diff --git a/docs/Compose file reference (legacy)/compose-versioning.md b/docs/Compose file reference (legacy)/compose-versioning.md
new file mode 100644
index 00000000000..63acae76ec0
--- /dev/null
+++ b/docs/Compose file reference (legacy)/compose-versioning.md	
@@ -0,0 +1,474 @@
+There are three legacy versions of the Compose file format:
+
+- Version 1. This is specified by omitting a `version` key at the root of the YAML.
+
+- Version 2.x. This is specified with a `version: '2'` or `version: '2.1'`, etc., entry at the root of the YAML.
+
+- Version 3.x, designed to be cross-compatible between Compose and the Docker Engine's
+[swarm mode](https://docs.docker.com/engine/swarm/). This is specified with a `version: '3'` or `version: '3.1'`, etc., entry at the root of the YAML.
+
+The latest and recommended version of the Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/). This format merges the 2.x and 3.x versions and is implemented by **Compose 1.27.0+**.
+
+
+> **Note** 
+>
+> If you're using [multiple Compose files](https://docs.docker.com/compose/multiple-compose-files/) or
+> [extending services](https://docs.docker.com/compose/multiple-compose-files/extends/),
+> each file must be of the same version - you cannot, for example,
+> mix version 1 and 2 in a single project.
+
+Several things differ depending on which version you use:
+
+- The structure and permitted configuration keys
+- The minimum Docker Engine version you must be running
+- Compose's behaviour with regards to networking
+
+These differences are explained below.
+
+### Version 2
+
+Compose files using the version 2 syntax must indicate the version number at
+the root of the document. All [services](compose-file-v2.md#service-configuration-reference)
+must be declared under the `services` key.
+
+Version 2 files are supported by **Compose 1.6.0+** and require a Docker Engine
+of version **1.10.0+**.
+
+Named [volumes](compose-file-v2.md#volume-configuration-reference) can be declared under the
+`volumes` key, and [networks](compose-file-v2.md#network-configuration-reference) can be declared
+under the `networks` key.
+
+By default, every container joins an application-wide default network, and is
+discoverable at a hostname that's the same as the service name. This means
+[links](compose-file-v2.md#links) are largely unnecessary. For more details, see
+[Networking in Compose](https://docs.docker.com/compose/networking/).
+
+> **Note**
+>
+> With Compose version 2, when specifying the Compose file version to use, make sure to
+> specify both the _major_ and _minor_ numbers. If no minor version is given,
+> `0` is used by default and not the latest minor version. As a result, features added in later versions will not be supported. For example:
+>
+> ```yaml
+> version: "2"
+> ```
+>
+> is equivalent to:
+>
+> ```yaml
+> version: "2.0"
+> ```
+
+Simple example:
+
+    version: "{{% param "compose_file_v2" %}}"
+    services:
+      web:
+        build: .
+        ports:
+         - "8000:5000"
+        volumes:
+         - .:/code
+      redis:
+        image: redis
+
+A more extended example, defining volumes and networks:
+
+    version: "{{% param "compose_file_v2" %}}"
+    services:
+      web:
+        build: .
+        ports:
+         - "8000:5000"
+        volumes:
+         - .:/code
+        networks:
+          - front-tier
+          - back-tier
+      redis:
+        image: redis
+        volumes:
+          - redis-data:/var/lib/redis
+        networks:
+          - back-tier
+    volumes:
+      redis-data:
+        driver: local
+    networks:
+      front-tier:
+        driver: bridge
+      back-tier:
+        driver: bridge
+
+Several other options were added to support networking, such as:
+
+* [`aliases`](compose-file-v2.md#aliases)
+
+* The [`depends_on`](compose-file-v2.md#depends_on) option can be used in place of links to indicate dependencies
+between services and startup order.
+
+      version: "{{% param "compose_file_v2" %}}"
+      services:
+        web:
+          build: .
+          depends_on:
+            - db
+            - redis
+        redis:
+          image: redis
+        db:
+          image: postgres
+
+* [`ipv4_address`, `ipv6_address`](compose-file-v2.md#ipv4_address-ipv6_address)
+
+[Variable substitution](compose-file-v2.md#variable-substitution) also was added in Version 2.
+
+### Version 2.1
+
+An upgrade of [version 2](#version-2) that introduces new parameters only
+available with Docker Engine version **1.12.0+**. Version 2.1 files are
+supported by **Compose 1.9.0+**.
+
+Introduces the following additional parameters:
+
+- [`link_local_ips`](compose-file-v2.md#link_local_ips)
+- [`isolation`](compose-file-v2.md#isolation-1) in build configurations and
+  service definitions
+- `labels` for [volumes](compose-file-v2.md#volume-configuration-reference),
+  [networks](compose-file-v2.md#network-configuration-reference), and
+  [build](compose-file-v3.md#build)
+- `name` for [volumes](compose-file-v2.md#volume-configuration-reference)
+- [`userns_mode`](compose-file-v2.md#userns_mode)
+- [`healthcheck`](compose-file-v2.md#healthcheck)
+- [`sysctls`](compose-file-v2.md#sysctls)
+- [`pids_limit`](compose-file-v2.md#pids_limit)
+- [`oom_kill_disable`](compose-file-v2.md#cpu-and-other-resources)
+- [`cpu_period`](compose-file-v2.md#cpu-and-other-resources)
+
+### Version 2.2
+
+An upgrade of [version 2.1](#version-21) that introduces new parameters only
+available with Docker Engine version **1.13.0+**.  Version 2.2 files are
+supported by **Compose 1.13.0+**. This version also allows you to specify
+default scale numbers inside the service's configuration.
+
+Introduces the following additional parameters:
+
+- [`init`](compose-file-v2.md#init)
+- [`scale`](compose-file-v2.md#scale)
+- [`cpu_rt_runtime` and `cpu_rt_period`](compose-file-v2.md#cpu_rt_runtime-cpu_rt_period)
+- [`network`](compose-file-v2.md#network) for [build configurations](compose-file-v2.md#build)
+
+### Version 2.3
+
+An upgrade of [version 2.2](#version-22) that introduces new parameters only
+available with Docker Engine version **17.06.0+**. Version 2.3 files are
+supported by **Compose 1.16.0+**.
+
+Introduces the following additional parameters:
+
+- [`target`](compose-file-v2.md#target), [`extra_hosts`](compose-file-v2.md#extra_hosts-1) and
+  [`shm_size`](compose-file-v2.md#shm_size) for [build configurations](compose-file-v2.md#build)
+- `start_period` for [`healthchecks`](compose-file-v2.md#healthcheck)
+- ["Long syntax" for volumes](compose-file-v2.md#long-syntax)
+- [`runtime`](compose-file-v2.md#runtime) for service definitions
+- [`device_cgroup_rules`](compose-file-v2.md#device_cgroup_rules)
+
+### Version 2.4
+
+An upgrade of [version 2.3](#version-23) that introduces new parameters only
+available with Docker Engine version **17.12.0+**. Version 2.4 files are
+supported by **Compose 1.21.0+**.
+
+Introduces the following additional parameters:
+
+- [`platform`](compose-file-v2.md#platform) for service definitions
+- Support for extension fields at the root of service, network, and volume
+  definitions
+
+### Version 3
+
+Designed to be cross-compatible between Compose and the Docker Engine's
+[swarm mode](/engine/swarm/), version 3 removes several options and adds
+several more.
+
+- Removed: `volume_driver`, `volumes_from`, `cpu_shares`, `cpu_quota`,
+  `cpuset`, `mem_limit`, `memswap_limit`, `extends`, `group_add`. See
+  the [upgrading](#upgrading) guide for how to migrate away from these.
+
+- Added: [deploy](compose-file-v3.md#deploy)
+
+If only the major version is given (`version: '3'`),
+the latest minor version is used by default.
+
+### Version 3.1
+
+An upgrade of [version 3](#version-3) that introduces new parameters only
+available with Docker Engine version **1.13.1+**, and higher.
+
+Introduces the following additional parameters:
+
+- [`secrets`](compose-file-v3.md#secrets)
+
+### Version 3.2
+
+An upgrade of [version 3](#version-3) that introduces new parameters only
+available with Docker Engine version **17.04.0+**, and higher.
+
+Introduces the following additional parameters:
+
+- [`cache_from`](compose-file-v3.md#cache_from) in [build configurations](compose-file-v3.md#build)
+- Long syntax for [ports](compose-file-v3.md#ports) and [volume mounts](compose-file-v3.md#volumes)
+- [`attachable`](compose-file-v3.md#attachable) network driver option
+- [deploy `endpoint_mode`](compose-file-v3.md#endpoint_mode)
+- [deploy placement `preference`](compose-file-v3.md#placement)
+
+### Version 3.3
+
+An upgrade of [version 3](#version-3) that introduces new parameters only
+available with Docker Engine version **17.06.0+**, and higher.
+
+Introduces the following additional parameters:
+
+- [build `labels`](compose-file-v3.md#build)
+- [`credential_spec`](compose-file-v3.md#credential_spec)
+- [`configs`](compose-file-v3.md#configs)
+
+### Version 3.4
+
+An upgrade of [version 3](#version-3) that introduces new parameters. It is
+only available with Docker Engine version **17.09.0** and higher.
+
+Introduces the following additional parameters:
+
+- [`target`](compose-file-v3.md#target) and [`network`](compose-file-v3.md#network) in
+  [build configurations](compose-file-v3.md#build)
+- `start_period` for [`healthchecks`](compose-file-v3.md#healthcheck)
+- `order` for [update configurations](compose-file-v3.md#update_config)
+- `name` for [volumes](compose-file-v3.md#volume-configuration-reference)
+
+### Version 3.5
+
+An upgrade of [version 3](#version-3) that introduces new parameters. It is
+only available with Docker Engine version **17.12.0** and higher.
+
+Introduces the following additional parameters:
+
+- [`isolation`](compose-file-v3.md#isolation) in service definitions
+- `name` for networks, secrets and configs
+- `shm_size` in [build configurations](compose-file-v3.md#build)
+
+### Version 3.6
+
+An upgrade of [version 3](#version-3) that introduces new parameters. It is
+only available with Docker Engine version **18.02.0** and higher.
+
+Introduces the following additional parameters:
+
+- [`tmpfs` size](compose-file-v3.md#long-syntax-3) for `tmpfs`-type mounts
+
+### Version 3.7
+
+An upgrade of [version 3](#version-3) that introduces new parameters. It is
+only available with Docker Engine version **18.06.0** and higher.
+
+Introduces the following additional parameters:
+
+- [`init`](compose-file-v3.md#init) in service definitions
+- [`rollback_config`](compose-file-v3.md#rollback_config) in deploy configurations
+- Support for extension fields at the root of service, network, volume, secret
+  and config definitions
+
+### Version 3.8
+
+An upgrade of [version 3](#version-3) that introduces new parameters. It is
+only available with Docker Engine version **19.03.0** and higher.
+
+Introduces the following additional parameters:
+
+- [`max_replicas_per_node`](compose-file-v3.md#max_replicas_per_node) in placement
+  configurations
+- `template_driver` option for [config](compose-file-v3.md#configs-configuration-reference)
+   and [secret](compose-file-v3.md#secrets-configuration-reference) configurations. This
+   option is only supported when deploying swarm services using
+   `docker stack deploy`.
+- `driver` and `driver_opts` option for [secret](compose-file-v3.md#secrets-configuration-reference)
+   configurations. This option is only supported when deploying swarm services
+   using `docker stack deploy`.
+
+### Version 1 (Deprecated)
+
+Compose versions below 1.6.x are 
+
+Compose files that do not declare a version are considered "version 1".  In those
+files, all the [services](compose-file-v3.md#service-configuration-reference) are
+declared at the root of the document.
+
+Version 1 is supported by Compose up to 1.6.x** and has been deprecated.
+
+Version 1 files cannot declare named
+[volumes](compose-file-v3.md#volume-configuration-reference), [networks](compose-file-v3.md#network-configuration-reference) or
+[build arguments](compose-file-v3.md#args).
+
+Compose does not take advantage of [networking](https://docs.docker.com/compose/networking/) when you
+use version 1: every container is placed on the default `bridge` network and is
+reachable from every other container at its IP address. You need to use
+`links` to enable discovery between containers.
+
+Example:
+
+    web:
+      build: .
+      ports:
+       - "8000:5000"
+      volumes:
+       - .:/code
+      links:
+       - redis
+    redis:
+      image: redis
+
+## Upgrading
+
+### Version 2.x to 3.x
+
+Between versions 2.x and 3.x, the structure of the Compose file is the same, but
+several options have been removed:
+
+-   `volume_driver`: Instead of setting the volume driver on the service, define
+    a volume using the
+    [top-level `volumes` option](compose-file-v3.md#volume-configuration-reference)
+    and specify the driver there.
+
+        version: "3.8"
+        services:
+          db:
+            image: postgres
+            volumes:
+              - data:/var/lib/postgresql/data
+        volumes:
+          data:
+            driver: mydriver
+
+-   `volumes_from`: To share a volume between services, define it using the
+    [top-level `volumes` option](compose-file-v3.md#volume-configuration-reference)
+    and reference it from each service that shares it using the
+    [service-level `volumes` option](compose-file-v3.md#driver).
+
+-   `cpu_shares`, `cpu_quota`, `cpuset`, `mem_limit`, `memswap_limit`: These
+    have been replaced by the [resources](compose-file-v3.md#resources) key under
+    `deploy`. `deploy` configuration only takes effect when using
+    `docker stack deploy`, and is ignored by `docker-compose`.
+
+-   `extends`: This option has been removed for `version: "3.x"` Compose files.
+    For more information on `extends`, see
+    [Extending services](https://docs.docker.com/compose/multiple-compose-files/extends/).
+-   `group_add`: This option has been removed for `version: "3.x"` Compose files.
+-   `pids_limit`: This option has not been introduced in `version: "3.x"` Compose files.
+-   `link_local_ips` in `networks`: This option has not been introduced in
+    `version: "3.x"` Compose files.
+
+#### Compatibility mode
+
+`docker-compose` 1.20.0 introduces a new `--compatibility` flag designed to
+help developers transition to version 3 more easily. When enabled,
+`docker-compose` reads the `deploy` section of each service's definition and
+attempts to translate it into the equivalent version 2 parameter. Currently,
+the following deploy keys are translated:
+
+- [resources](compose-file-v3.md#resources) limits and memory reservations
+- [replicas](compose-file-v3.md#replicas)
+- [restart_policy](compose-file-v3.md#restart_policy) `condition` and `max_attempts`
+
+All other keys are ignored and produce a warning if present. You can review
+the configuration that will be used to deploy by using the `--compatibility`
+flag with the `config` command.
+
+> Do not use this in production
+>
+> We recommend against using `--compatibility` mode in production. The
+> resulting configuration is only an approximate using non-Swarm mode
+> properties, it may produce unexpected results.
+
+### Version 1 to 2.x
+
+In the majority of cases, moving from version 1 to 2 is a very simple process:
+
+1. Indent the whole file by one level and put a `services:` key at the top.
+2. Add a `version: '2'` line at the top of the file.
+
+It's more complicated if you're using particular configuration features:
+
+-   `dockerfile`: This now lives under the `build` key:
+
+        build:
+          context: .
+          dockerfile: Dockerfile-alternate
+
+-   `log_driver`, `log_opt`: These now live under the `logging` key:
+
+        logging:
+          driver: syslog
+          options:
+            syslog-address: "tcp://192.168.0.42:123"
+
+-   `links` with environment variables: environment variables created by
+    links, such as `CONTAINERNAME_PORT`, ` have been deprecated for some time. In the new Docker network system,
+    they have been removed. You should either connect directly to the
+    appropriate hostname or set the relevant environment variable yourself,
+    using the link hostname:
+
+        web:
+          links:
+            - db
+          environment:
+            - DB_PORT=tcp://db:5432
+
+-   `external_links`: Compose uses Docker networks when running version 2
+    projects, so links behave slightly differently. In particular, two
+    containers must be connected to at least one network in common in order to
+    communicate, even if explicitly linked together.
+
+    Either connect the external container to your app's
+    [default network](https://docs.docker.com/compose/networking/), or connect both the external container and
+    your service's containers to an
+    [external network](https://docs.docker.com/compose/networking/).
+
+-   `net`: This is now replaced by [network_mode](compose-file-v3.md#network_mode):
+
+        net: host    ->  network_mode: host
+        net: bridge  ->  network_mode: bridge
+        net: none    ->  network_mode: none
+
+    If you're using `net: "container:[service name]"`, you must now use
+    `network_mode: "service:[service name]"` instead.
+
+        net: "container:web"  ->  network_mode: "service:web"
+
+    If you're using `net: "container:[container name/id]"`, the value does not
+    need to change.
+
+        net: "container:cont-name"  ->  network_mode: "container:cont-name"
+        net: "container:abc12345"   ->  network_mode: "container:abc12345"
+
+-   `volumes` with named volumes: these must now be explicitly declared in a
+    top-level `volumes` section of your Compose file. If a service mounts a
+    named volume called `data`, you must declare a `data` volume in your
+    top-level `volumes` section. The whole file might look like this:
+
+        version: "{{% param "compose_file_v2" %}}"
+        services:
+          db:
+            image: postgres
+            volumes:
+              - data:/var/lib/postgresql/data
+        volumes:
+          data: {}
+
+    By default, Compose creates a volume whose name is prefixed with your
+    project name. If you want it to just be called `data`, declare it as
+    external:
+
+        volumes:
+          data:
+            external: true
diff --git a/docs/Compose file reference/version-2.md b/docs/Compose file reference (legacy)/version-2.md
similarity index 84%
rename from docs/Compose file reference/version-2.md
rename to docs/Compose file reference (legacy)/version-2.md
index 7865755317f..0d3eb6c0648 100644
--- a/docs/Compose file reference/version-2.md	
+++ b/docs/Compose file reference (legacy)/version-2.md	
@@ -1,4 +1,6 @@
-These topics describe version 2 of the Compose file format.
+This page describes version 2 of the Compose file format. 
+
+This is legacy content. The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**.
 
 ## Compose and Docker compatibility matrix
 
@@ -6,7 +8,33 @@ There are several versions of the Compose file format – 1, 2, 2.x, and 3.x. Th
 table below is a quick look. For full details on what each version includes and
 how to upgrade, see **[About versions and upgrading](compose-versioning.md)**.
 
-{{< include "content/compose-matrix.md" >}}
+This table shows which Compose file versions support specific Docker releases.
+
+| **Compose file format** | **Docker Engine release** |
+|  -------------------    |    ------------------     |
+|  Compose specification  |       19.03.0+            |
+|      3.8                |       19.03.0+            |
+|      3.7                |       18.06.0+            |
+|      3.6                |       18.02.0+            |
+|      3.5                |       17.12.0+            |
+|      3.4                |       17.09.0+            |
+|      3.3                |       17.06.0+            |
+|      3.2                |       17.04.0+            |
+|      3.1                |       1.13.1+             |
+|      3.0                |       1.13.0+             |
+|      2.4                |       17.12.0+            |
+|      2.3                |       17.06.0+            |
+|      2.2                |       1.13.0+             |
+|      2.1                |       1.12.0+             |
+|      2.0                |       1.10.0+             |
+
+In addition to Compose file format versions shown in the table, the Compose
+itself is on a release schedule, as shown in [Compose
+releases](https://github.com/docker/compose/releases/), but file format versions
+do not necessarily increment with each release. For example, Compose file format
+3.0 was first introduced in [Compose release
+1.10.0](https://github.com/docker/compose/releases/tag/1.10.0), and versioned
+gradually in subsequent releases.
 
 ## Service configuration reference
 
@@ -205,7 +233,7 @@ build:
 > In your Dockerfile, if you specify `ARG` before the `FROM` instruction,
 > `ARG` is not available in the build instructions under `FROM`.
 > If you need an argument to be available in both places, also specify it under
-> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](../../reference/dockerfile.md#understand-how-arg-and-from-interact)
+> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](https://docs.docker.com/reference/dockerfile#understand-how-arg-and-from-interact)
 > section in the documentation for usage details.
 
 You can omit the value when specifying a build argument, in which case its value
@@ -261,7 +289,7 @@ An entry with the ip address and hostname is created in `/etc/hosts` inside cont
 Specify a build’s container isolation technology. On Linux, the only supported value
 is `default`. On Windows, acceptable values are `default`, `process` and
 `hyperv`. Refer to the
-[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation)
+[Docker Engine docs](https://docs.docker.com/reference/cli/docker/container/run#isolation)
 for details.
 
 If unspecified, Compose will use the `isolation` value found in the service's definition
@@ -271,7 +299,7 @@ to determine the value to use for builds.
 
 > Added in [version 2.1](compose-versioning.md#version-21) file format
 
-Add metadata to the resulting image using [Docker labels](../../config/labels-custom-metadata.md).
+Add metadata to the resulting image using [Docker labels](https://docs.docker.com/config/labels-custom-metadata).
 You can use either an array or a dictionary.
 
 It's recommended that you use reverse-DNS notation to prevent your labels from
@@ -347,7 +375,7 @@ build:
 > Added in [version 2.3](compose-versioning.md#version-23) file format
 
 Build the specified stage as defined inside the `Dockerfile`. See the
-[multi-stage build docs](../../build/building/multi-stage.md) for
+[multi-stage build docs](https://docs.docker.com/build/building/multi-stage) for
 details.
 
 ```yaml
@@ -387,7 +415,7 @@ command: bundle exec thin -p 3000
 ```
 
 The command can also be a list, in a manner similar to
-[dockerfile](../../reference/dockerfile.md#cmd):
+[dockerfile](https://docs.docker.com/reference/dockerfile#cmd):
 
 ```yaml
 command: ["bundle", "exec", "thin", "-p", "3000"]
@@ -480,7 +508,7 @@ services:
 >
 > `depends_on` does not wait for `db` and `redis` to be "ready" before
 > starting `web` - only until they have been started. If you need to wait
-> for a service to be ready, see [Controlling startup order](../startup-order.md)
+> for a service to be ready, see [Controlling startup order](https://docs.docker.com/compose/startup-order/)
 > for more on this problem and strategies for solving it.
 
 > Added in [version 2.1](compose-versioning.md#version-21) file format.
@@ -562,7 +590,7 @@ entrypoint: /code/entrypoint.sh
 ```
 
 The entrypoint can also be a list, in a manner similar to
-[dockerfile](../../reference/dockerfile.md#entrypoint):
+[dockerfile](https://docs.docker.com/reference/dockerfile#entrypoint):
 
 ```yaml
 entrypoint: ["php", "-d", "memory_limit=-1", "vendor/bin/phpunit"]
@@ -718,7 +746,7 @@ indefinitely. Compose does not support circular references and `docker-compose`
 returns an error if it encounters one.
 
 For more on `extends`, see the
-[the extends documentation](../multiple-compose-files/extends.md)
+[the extends documentation](https://docs.docker.com/compose/multiple-compose-files/extends)
 
 ### external_links
 
@@ -766,7 +794,7 @@ host system to be added. An example of where this is useful is when multiple
 containers (running as different users) need to all read or write the same
 file on the host system. That file can be owned by a group shared by all the
 containers, and specified in `group_add`. See the
-[Docker documentation](../../reference/cli/docker/container/run.md#additional-groups) for more
+[Docker documentation](https://docs.docker.com/reference/cli/docker/container/run#additional-groups) for more
 details.
 
 A full example:
@@ -790,7 +818,7 @@ used.
 
 Configure a check that's run to determine whether or not containers for this
 service are "healthy". See the docs for the
-[HEALTHCHECK Dockerfile instruction](../../reference/dockerfile.md#healthcheck)
+[HEALTHCHECK Dockerfile instruction](https://docs.docker.com/reference/dockerfile#healthcheck)
 for details on how healthchecks work.
 
 ```yaml
@@ -879,7 +907,7 @@ services:
 > The default init binary that is used is [Tini](https://github.com/krallin/tini),
 > and is installed in `/usr/libexec/docker-init` on the daemon host. You can
 > configure the daemon to use a custom init binary through the
-> [`init-path` configuration option](../../reference/cli/dockerd.md#daemon-configuration-file).
+> [`init-path` configuration option](https://docs.docker.com/reference/cli/dockerd#daemon-configuration-file).
 
 ### isolation
 
@@ -888,12 +916,12 @@ services:
 Specify a container’s isolation technology. On Linux, the only supported value
 is `default`. On Windows, acceptable values are `default`, `process` and
 `hyperv`. Refer to the
-[Docker Engine docs](../../reference/cli/docker/container/run.md#isolation)
+[Docker Engine docs](https://docs.docker.com/reference/cli/docker/container/run#isolation)
 for details.
 
 ### labels
 
-Add metadata to containers using [Docker labels](../../config/labels-custom-metadata.md). You can use either an array or a dictionary.
+Add metadata to containers using [Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary.
 
 It's recommended that you use reverse-DNS notation to prevent your labels from conflicting with those used by other software.
 
@@ -932,7 +960,7 @@ the alias, or the service name if no alias was specified.
 
 Links are not required to enable services to communicate - by default,
 any service can reach any other service at that service’s name. (See also, the
-[Links topic in Networking in Compose](../networking.md#link-containers).)
+[Links topic in Networking in Compose](https://docs.docker.com/compose/networking#link-containers).)
 
 Links also express dependency between services in the same way as
 [depends_on](#depends_on), so they determine the order of service startup.
@@ -956,7 +984,7 @@ logging:
 
 The `driver`  name specifies a logging driver for the service's
 containers, as with the ``--log-driver`` option for docker run
-([documented here](../../config/containers/logging/configure.md)).
+([documented here](https://docs.docker.com/config/containers/logging/configure)).
 
 The default value is json-file.
 
@@ -1282,7 +1310,7 @@ web:
 Specify the default number of containers to deploy for this service. Whenever
 you run `docker-compose up`, Compose creates or removes containers to match
 the specified number. This value can be overridden using the
-[`--scale`](../../reference/cli/docker/compose/up.md)
+[`--scale`](https://docs.docker.com/reference/cli/docker/compose/up)
 
 ```yaml
 web:
@@ -1395,7 +1423,7 @@ userns_mode: "host"
 ```
 
 Disables the user namespace for this service, if Docker daemon is configured with user namespaces.
-See [dockerd](../../engine/security/userns-remap.md#disable-namespace-remapping-for-a-container) for
+See [dockerd](https://docs.docker.com/engine/security/userns-remap#disable-namespace-remapping-for-a-container) for
 more information.
 
 ### volumes
@@ -1483,7 +1511,7 @@ volumes:
 > When creating bind mounts, using the long syntax requires the
 > referenced folder to be created beforehand. Using the short syntax
 > creates the folder on the fly if it doesn't exist.
-> See the [bind mounts documentation](../../storage/bind-mounts.md#differences-between--v-and---mount-behavior)
+> See the [bind mounts documentation](https://docs.docker.com/storage/bind-mounts#differences-between--v-and---mount-behavior)
 > for more information.
 
 ### volume\_driver
@@ -1504,7 +1532,7 @@ volume_driver: mydriver
 > entry in the [top-level `volumes` option](#volume-configuration-reference).
 
 
-See [Docker Volumes](../../storage/volumes.md) and
+See [Docker Volumes](https://docs.docker.com/storage/volumes) and
 [Volume Plugins](/engine/extend/plugins_volume/) for more information.
 
 ### volumes_from
@@ -1545,7 +1573,7 @@ restart: "unless-stopped"
 ### cpu_count, cpu_percent, cpu\_shares, cpu\_period, cpu\_quota, cpus, cpuset, domainname, hostname, ipc, mac\_address, mem\_limit, memswap\_limit, mem\_swappiness, mem\_reservation, oom_kill_disable, oom_score_adj, privileged, read\_only, shm\_size, stdin\_open, tty, user, working\_dir
 
 Each of these is a single value, analogous to its
-[docker run](../../reference/cli/docker/container/run.md#runtime-constraints-on-resources) counterpart.
+[docker run](https://docs.docker.com/reference/cli/docker/container/run#runtime-constraints-on-resources) counterpart.
 
 > Added in [version 2.2](compose-versioning.md#version-22) file format.
 >
@@ -1623,10 +1651,10 @@ While it is possible to declare [volumes](#volumes) on the fly as part of the
 service declaration, this section allows you to create named volumes that can be
 reused across multiple services (without relying on `volumes_from`), and are
 easily retrieved and inspected using the docker command line or API.
-See the [docker volume](../../reference/cli/docker/volume/create.md)
+See the [docker volume](https://docs.docker.com/reference/cli/docker/volume/create)
 subcommand documentation for more information.
 
-See [use volumes](../../storage/volumes.md) and [volume plugins](/engine/extend/plugins_volume/)
+See [use volumes](https://docs.docker.com/storage/volumes) and [volume plugins](/engine/extend/plugins_volume/)
 for general information on volumes.
 
 Here's an example of a two-service setup where a database's data directory is
@@ -1729,7 +1757,7 @@ volumes:
 > Added in [version 2.1](compose-versioning.md#version-21) file format.
 
 Add metadata to containers using
-[Docker labels](../../config/labels-custom-metadata.md). You can use either
+[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either
 an array or a dictionary.
 
 It's recommended that you use reverse-DNS notation to prevent your labels from
@@ -1778,7 +1806,7 @@ volumes:
 
 The top-level `networks` key lets you specify networks to be created. For a full
 explanation of Compose's use of Docker networking features, see the
-[Networking guide](../networking.md).
+[Networking guide](https://docs.docker.com/compose/networking).
 
 ### driver
 
@@ -1862,7 +1890,7 @@ you can set this option to `true`.
 > Added in [version 2.1](compose-versioning.md#version-21) file format.
 
 Add metadata to containers using
-[Docker labels](../../config/labels-custom-metadata.md). You can use either
+[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either
 an array or a dictionary.
 
 It's recommended that you use reverse-DNS notation to prevent your labels from
@@ -1958,10 +1986,151 @@ networks:
 
 ## Variable substitution
 
-{{< include "content/compose-var-sub.md" >}}
+Your configuration options can contain environment variables. Compose uses the
+variable values from the shell environment in which `docker compose` is run. For
+example, suppose the shell contains `POSTGRES_VERSION=9.3` and you supply this
+configuration:
+
+```yaml
+db:
+  image: "postgres:${POSTGRES_VERSION}"
+```
+
+When you run `docker compose up` with this configuration, Compose looks for the
+`POSTGRES_VERSION` environment variable in the shell and substitutes its value
+in. For this example, Compose resolves the `image` to `postgres:9.3` before
+running the configuration.
+
+If an environment variable is not set, Compose substitutes with an empty
+string. In the example above, if `POSTGRES_VERSION` is not set, the value for
+the `image` option is `postgres:`.
+
+You can set default values for environment variables using a
+`.env` file, which Compose automatically looks for in
+project directory (parent folder of your Compose file). 
+Values set in the shell environment override those set in the `.env` file.
+
+> Note when using docker stack deploy
+>
+> The `.env file` feature only works when you use the `docker compose up` command
+> and does not work with `docker stack deploy`.
+{ .important }
+
+Both `$VARIABLE` and `${VARIABLE}` syntax are supported. Additionally when using
+the [2.1 file format](compose-versioning.md#version-21), it is possible to
+provide inline default values using typical shell syntax:
+
+- `${VARIABLE:-default}` evaluates to `default` if `VARIABLE` is unset or
+  empty in the environment.
+- `${VARIABLE-default}` evaluates to `default` only if `VARIABLE` is unset
+  in the environment.
+
+Similarly, the following syntax allows you to specify mandatory variables:
+
+- `${VARIABLE:?err}` exits with an error message containing `err` if
+  `VARIABLE` is unset or empty in the environment.
+- `${VARIABLE?err}` exits with an error message containing `err` if
+  `VARIABLE` is unset in the environment.
+
+Other extended shell-style features, such as `${VARIABLE/foo/bar}`, are not
+supported.
+
+You can use a `$$` (double-dollar sign) when your configuration needs a literal
+dollar sign. This also prevents Compose from interpolating a value, so a `$$`
+allows you to refer to environment variables that you don't want processed by
+Compose.
+
+```yaml
+web:
+  build: .
+  command: "$$VAR_NOT_INTERPOLATED_BY_COMPOSE"
+```
+
+If you forget and use a single dollar sign (`$`), Compose interprets the value
+as an environment variable and warns you:
+
+```console
+The VAR_NOT_INTERPOLATED_BY_COMPOSE is not set. Substituting an empty string.
+```
 
 ## Extension fields
 
 > Added in [version 2.1](compose-versioning.md#version-21) file format.
 
-{{< include "content/compose-extfields-sub.md" >}}
+It is possible to re-use configuration fragments using extension fields. Those
+special fields can be of any format as long as they are located at the root of
+your Compose file and their name start with the `x-` character sequence.
+
+> **Note**
+>
+> Starting with the 3.7 format (for the 3.x series) and 2.4 format
+> (for the 2.x series), extension fields are also allowed at the root
+> of service, volume, network, config and secret definitions.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-custom:
+  items:
+    - a
+    - b
+  options:
+    max-size: '12m'
+  name: "custom"
+```
+
+The contents of those fields are ignored by Compose, but they can be
+inserted in your resource definitions using [YAML anchors](https://yaml.org/spec/1.2/spec.html#id2765878).
+For example, if you want several of your services to use the same logging
+configuration:
+
+```yaml
+logging:
+  options:
+    max-size: '12m'
+    max-file: '5'
+  driver: json-file
+```
+
+You may write your Compose file as follows:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-logging:
+  &default-logging
+  options:
+    max-size: '12m'
+    max-file: '5'
+  driver: json-file
+
+services:
+  web:
+    image: myapp/web:latest
+    logging: *default-logging
+  db:
+    image: mysql:latest
+    logging: *default-logging
+```
+
+It is also possible to partially override values in extension fields using
+the [YAML merge type](https://yaml.org/type/merge.html). For example:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-volumes:
+  &default-volume
+  driver: foobar-storage
+
+services:
+  web:
+    image: myapp/web:latest
+    volumes: ["vol1", "vol2", "vol3"]
+volumes:
+  vol1: *default-volume
+  vol2:
+    << : *default-volume
+    name: volume02
+  vol3:
+    << : *default-volume
+    driver: default
+    name: volume-local
+```
diff --git a/docs/Compose file reference (legacy)/version-3.md b/docs/Compose file reference (legacy)/version-3.md
new file mode 100644
index 00000000000..d95d3c33edd
--- /dev/null
+++ b/docs/Compose file reference (legacy)/version-3.md	
@@ -0,0 +1,2913 @@
+
+This page describes version 3 of the Compose file format. 
+
+This is legacy content. The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**.
+ 
+## Compose and Docker compatibility matrix
+
+There are several versions of the Compose file format – 1, 2, 2.x, and 3.x. The
+table below is a quick look. For full details on what each version includes and
+how to upgrade, see **[About versions and upgrading](compose-versioning.md)**.
+
+This table shows which Compose file versions support specific Docker releases.
+
+| **Compose file format** | **Docker Engine release** |
+|  -------------------    |    ------------------     |
+|  Compose specification  |       19.03.0+            |
+|      3.8                |       19.03.0+            |
+|      3.7                |       18.06.0+            |
+|      3.6                |       18.02.0+            |
+|      3.5                |       17.12.0+            |
+|      3.4                |       17.09.0+            |
+|      3.3                |       17.06.0+            |
+|      3.2                |       17.04.0+            |
+|      3.1                |       1.13.1+             |
+|      3.0                |       1.13.0+             |
+|      2.4                |       17.12.0+            |
+|      2.3                |       17.06.0+            |
+|      2.2                |       1.13.0+             |
+|      2.1                |       1.12.0+             |
+|      2.0                |       1.10.0+             |
+
+In addition to Compose file format versions shown in the table, the Compose
+itself is on a release schedule, as shown in [Compose
+releases](https://github.com/docker/compose/releases/), but file format versions
+do not necessarily increment with each release. For example, Compose file format
+3.0 was first introduced in [Compose release
+1.10.0](https://github.com/docker/compose/releases/tag/1.10.0), and versioned
+gradually in subsequent releases.
+
+The latest Compose file format is defined by the [Compose Specification](https://docs.docker.com/compose/compose-file/) and is implemented by Docker Compose **1.27.0+**.
+
+## Compose file structure and examples
+
+Here is a sample Compose file from the voting app sample used in the
+[Docker for Beginners lab](https://github.com/docker/labs/tree/master/beginner/)
+topic on [Deploying an app to a Swarm](https://github.com/docker/labs/blob/master/beginner/chapters/votingapp.md):
+
+    
+{{< accordion title="Example Compose file version 3" >}}
+
+```yml
+version: "{{% param "compose_file_v3" %}}"
+services:
+
+  redis:
+    image: redis:alpine
+    ports:
+      - "6379"
+    networks:
+      - frontend
+    deploy:
+      replicas: 2
+      update_config:
+        parallelism: 2
+        delay: 10s
+      restart_policy:
+        condition: on-failure
+
+  db:
+    image: postgres:9.4
+    volumes:
+      - db-data:/var/lib/postgresql/data
+    networks:
+      - backend
+    deploy:
+      placement:
+        max_replicas_per_node: 1
+        constraints:
+          - "node.role==manager"
+
+  vote:
+    image: dockersamples/examplevotingapp_vote:before
+    ports:
+      - "5000:80"
+    networks:
+      - frontend
+    depends_on:
+      - redis
+    deploy:
+      replicas: 2
+      update_config:
+        parallelism: 2
+      restart_policy:
+        condition: on-failure
+
+  result:
+    image: dockersamples/examplevotingapp_result:before
+    ports:
+      - "5001:80"
+    networks:
+      - backend
+    depends_on:
+      - db
+    deploy:
+      replicas: 1
+      update_config:
+        parallelism: 2
+        delay: 10s
+      restart_policy:
+        condition: on-failure
+
+  worker:
+    image: dockersamples/examplevotingapp_worker
+    networks:
+      - frontend
+      - backend
+    deploy:
+      mode: replicated
+      replicas: 1
+      labels: [APP=VOTING]
+      restart_policy:
+        condition: on-failure
+        delay: 10s
+        max_attempts: 3
+        window: 120s
+      placement:
+        constraints:
+          - "node.role==manager"
+
+  visualizer:
+    image: dockersamples/visualizer:stable
+    ports:
+      - "8080:8080"
+    stop_grace_period: 1m30s
+    volumes:
+      - "/var/run/docker.sock:/var/run/docker.sock"
+    deploy:
+      placement:
+        constraints:
+          - "node.role==manager"
+
+networks:
+  frontend:
+  backend:
+
+volumes:
+  db-data:
+```
+{{< /accordion >}}
+
+The topics on this reference page are organized alphabetically by top-level key
+to reflect the structure of the Compose file itself. Top-level keys that define
+a section in the configuration file such as `build`, `deploy`, `depends_on`,
+`networks`, and so on, are listed with the options that support them as
+sub-topics. This maps to the `<key>: <option>: <value>` indent structure of the
+Compose file.
+
+## Service configuration reference
+
+The Compose file is a [YAML](https://yaml.org) file defining
+[services](#service-configuration-reference),
+[networks](#network-configuration-reference) and
+[volumes](#volume-configuration-reference).
+The default path for a Compose file is `./docker-compose.yml`.
+
+> **Tip**: You can use either a `.yml` or `.yaml` extension for this file.
+> They both work.
+
+A service definition contains configuration that is applied to each
+container started for that service, much like passing command-line parameters to
+`docker run`. Likewise, network and volume definitions are analogous to
+`docker network create` and `docker volume create`.
+
+As with `docker run`, options specified in the Dockerfile, such as `CMD`,
+`EXPOSE`, `VOLUME`, `ENV`, are respected by default - you don't need to
+specify them again in `docker-compose.yml`.
+
+You can use environment variables in configuration values with a Bash-like
+`${VARIABLE}` syntax - see [variable substitution](#variable-substitution) for
+full details.
+
+This section contains a list of all configuration options supported by a service
+definition in version 3.
+
+### build
+
+Configuration options that are applied at build time.
+
+`build` can be specified either as a string containing a path to the build
+context:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  webapp:
+    build: ./dir
+```
+
+Or, as an object with the path specified under [context](#context) and
+optionally [Dockerfile](#dockerfile) and [args](#args):
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  webapp:
+    build:
+      context: ./dir
+      dockerfile: Dockerfile-alternate
+      args:
+        buildno: 1
+```
+
+If you specify `image` as well as `build`, then Compose names the built image
+with the `webapp` and optional `tag` specified in `image`:
+
+```yaml
+build: ./dir
+image: webapp:tag
+```
+
+This results in an image named `webapp` and tagged `tag`, built from `./dir`.
+
+> Note when using docker stack deploy
+>
+> The `build` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/engine/swarm/stack-deploy/)
+> The `docker stack` command does not build images before deploying.
+{ .important }
+
+#### context
+
+Either a path to a directory containing a Dockerfile, or a url to a git repository.
+
+When the value supplied is a relative path, it is interpreted as relative to the
+location of the Compose file. This directory is also the build context that is
+sent to the Docker daemon.
+
+Compose builds and tags it with a generated name, and uses that image
+thereafter.
+
+```yaml
+build:
+  context: ./dir
+```
+
+#### dockerfile
+
+Alternate Dockerfile.
+
+Compose uses an alternate file to build with. A build path must also be
+specified.
+
+```yaml
+build:
+  context: .
+  dockerfile: Dockerfile-alternate
+```
+
+#### args
+
+Add build arguments, which are environment variables accessible only during the
+build process.
+
+First, specify the arguments in your Dockerfile:
+
+```dockerfile
+# syntax=docker/dockerfile:1
+
+ARG buildno
+ARG gitcommithash
+
+RUN echo "Build number: $buildno"
+RUN echo "Based on commit: $gitcommithash"
+```
+
+Then specify the arguments under the `build` key. You can pass a mapping
+or a list:
+
+```yaml
+build:
+  context: .
+  args:
+    buildno: 1
+    gitcommithash: cdc3b19
+```
+
+```yaml
+build:
+  context: .
+  args:
+    - buildno=1
+    - gitcommithash=cdc3b19
+```
+
+> Scope of build-args
+>
+> In your Dockerfile, if you specify `ARG` before the `FROM` instruction,
+> `ARG` is not available in the build instructions under `FROM`.
+> If you need an argument to be available in both places, also specify it under
+> the `FROM` instruction. Refer to the [understand how ARGS and FROM interact](https://docs.docker.com/reference/dockerfile/#understand-how-arg-and-from-interact)
+> section in the documentation for usage details.
+
+You can omit the value when specifying a build argument, in which case its value
+at build time is the value in the environment where Compose is running.
+
+```yaml
+args:
+  - buildno
+  - gitcommithash
+```
+
+> Tip when using boolean values
+>
+> YAML boolean values (`"true"`, `"false"`, `"yes"`, `"no"`, `"on"`,
+> `"off"`) must be enclosed in quotes, so that the parser interprets them as
+> strings.
+
+#### cache_from
+
+> Added in [version 3.2](compose-versioning.md#version-32) file format
+
+A list of images that the engine uses for cache resolution.
+
+```yaml
+build:
+  context: .
+  cache_from:
+    - alpine:latest
+    - corp/web_app:3.14
+```
+
+#### labels
+
+> Added in [version 3.3](compose-versioning.md#version-33) file format
+
+Add metadata to the resulting image using [Docker labels](https://docs.docker.com/config/labels-custom-metadata/).
+You can use either an array or a dictionary.
+
+It's recommended that you use reverse-DNS notation to prevent your labels from
+conflicting with those used by other software.
+
+```yaml
+build:
+  context: .
+  labels:
+    com.example.description: "Accounting webapp"
+    com.example.department: "Finance"
+    com.example.label-with-empty-value: ""
+```
+
+```yaml
+build:
+  context: .
+  labels:
+    - "com.example.description=Accounting webapp"
+    - "com.example.department=Finance"
+    - "com.example.label-with-empty-value"
+```
+
+#### network
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format
+
+Set the network containers connect to for the `RUN` instructions during
+build.
+
+```yaml
+build:
+  context: .
+  network: host
+```
+
+```yaml
+build:
+  context: .
+  network: custom_network_1
+```
+
+Use `none` to disable networking during build:
+
+```yaml
+build:
+  context: .
+  network: none
+```
+
+#### shm_size
+
+> Added in [version 3.5](compose-versioning.md#version-35) file format
+
+Set the size of the `/dev/shm` partition for this build's containers. Specify
+as an integer value representing the number of bytes or as a string expressing
+a [byte value](#specifying-byte-values).
+
+```yaml
+build:
+  context: .
+  shm_size: '2gb'
+```
+
+```yaml
+build:
+  context: .
+  shm_size: 10000000
+```
+
+#### target
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format
+
+Build the specified stage as defined inside the `Dockerfile`. See the
+[multi-stage build docs](https://docs.docker.com/build/building/multi-stage/) for
+details.
+
+```yaml
+build:
+  context: .
+  target: prod
+```
+
+### cap_add, cap_drop
+
+Add or drop container capabilities.
+See `man 7 capabilities` for a full list.
+
+```yaml
+cap_add:
+  - ALL
+
+cap_drop:
+  - NET_ADMIN
+  - SYS_ADMIN
+```
+
+### cgroup_parent
+
+Specify an optional parent cgroup for the container.
+
+```yaml
+cgroup_parent: m-executor-abcd
+```
+
+> Note when using docker stack deploy
+>
+> The `cgroup_parent` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy/)
+{ .important }
+
+### command
+
+Override the default command.
+
+```yaml
+command: bundle exec thin -p 3000
+```
+
+The command can also be a list, in a manner similar to
+[dockerfile](https://docs.docker.com/reference/dockerfile#cmd):
+
+```yaml
+command: ["bundle", "exec", "thin", "-p", "3000"]
+```
+
+### configs
+
+Grant access to configs on a per-service basis using the per-service `configs`
+configuration. Two different syntax variants are supported.
+
+> **Note**: The config must already exist or be
+> [defined in the top-level `configs` configuration](#configs-configuration-reference)
+> of this stack file, or stack deployment fails.
+
+For more information on configs, see [configs](https://docs.docker.com/engine/swarm/configs).
+
+#### Short syntax
+
+The short syntax variant only specifies the config name. This grants the
+container access to the config and mounts it at `/<config_name>`
+within the container. The source name and destination mountpoint are both set
+to the config name.
+
+The following example uses the short syntax to grant the `redis` service
+access to the `my_config` and `my_other_config` configs. The value of
+`my_config` is set to the contents of the file `./my_config.txt`, and
+`my_other_config` is defined as an external resource, which means that it has
+already been defined in Docker, either by running the `docker config create`
+command or by another stack deployment. If the external config does not exist,
+the stack deployment fails with a `config not found` error.
+
+> Added in [version 3.3](compose-versioning.md#version-33) file format.
+> 
+> `config` definitions are only supported in version 3.3 and higher  of the
+> compose file format.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:latest
+    deploy:
+      replicas: 1
+    configs:
+      - my_config
+      - my_other_config
+configs:
+  my_config:
+    file: ./my_config.txt
+  my_other_config:
+    external: true
+```
+
+#### Long syntax
+
+The long syntax provides more granularity in how the config is created within
+the service's task containers.
+
+- `source`: The identifier of the config as it is defined in this configuration.
+- `target`: The path and name of the file to be mounted in the service's
+  task containers. Defaults to `/<source>` if not specified.
+- `uid` and `gid`: The numeric UID or GID that owns the mounted config file
+  within in the service's task containers. Both default to `0` on Linux if not
+  specified. Not supported on Windows.
+- `mode`: The permissions for the file that is mounted within the service's
+  task containers, in octal notation. For instance, `0444`
+  represents world-readable. The default is `0444`. Configs cannot be writable
+  because they are mounted in a temporary filesystem, so if you set the writable
+  bit, it is ignored. The executable bit can be set. If you aren't familiar with
+  UNIX file permission modes, you may find this
+  [permissions calculator](http://permissions-calculator.org/)
+  useful.
+
+The following example sets the name of `my_config` to `redis_config` within the
+container, sets the mode to `0440` (group-readable) and sets the user and group
+to `103`. The `redis` service does not have access to the `my_other_config`
+config.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:latest
+    deploy:
+      replicas: 1
+    configs:
+      - source: my_config
+        target: /redis_config
+        uid: '103'
+        gid: '103'
+        mode: 0440
+configs:
+  my_config:
+    file: ./my_config.txt
+  my_other_config:
+    external: true
+```
+
+You can grant a service access to multiple configs and you can mix long and
+short syntax. Defining a config does not imply granting a service access to it.
+
+### container_name
+
+Specify a custom container name, rather than a generated default name.
+
+```yaml
+container_name: my-web-container
+```
+
+Because Docker container names must be unique, you cannot scale a service beyond
+1 container if you have specified a custom name. Attempting to do so results in
+an error.
+
+> Note when using docker stack deploy
+>
+> The `container_name` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy)
+{ .important }
+
+### credential_spec
+
+> Added in [version 3.3](compose-versioning.md#version-33) file format.
+> 
+> The `credential_spec` option was added in v3.3. Using group Managed Service
+> Account (gMSA) configurations with compose files is supported in file format
+> version 3.8 or up.
+
+Configure the credential spec for managed service account. This option is only
+used for services using Windows containers. The `credential_spec` must be in the
+format `file://<filename>` or `registry://<value-name>`.
+
+When using `file:`, the referenced file must be present in the `CredentialSpecs`
+subdirectory in the Docker data directory, which defaults to `C:\ProgramData\Docker\`
+on Windows. The following example loads the credential spec from a file named
+`C:\ProgramData\Docker\CredentialSpecs\my-credential-spec.json`.
+
+```yaml
+credential_spec:
+  file: my-credential-spec.json
+```
+
+When using `registry:`, the credential spec is read from the Windows registry on
+the daemon's host. A registry value with the given name must be located in:
+
+    HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Virtualization\Containers\CredentialSpecs
+
+The following example load the credential spec from a value named `my-credential-spec`
+in the registry:
+
+```yaml
+credential_spec:
+  registry: my-credential-spec
+```
+
+#### Example gMSA configuration
+
+When configuring a gMSA credential spec for a service, you only need
+to specify a credential spec with `config`, as shown in the following example:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  myservice:
+    image: myimage:latest
+    credential_spec:
+      config: my_credential_spec
+
+configs:
+  my_credentials_spec:
+    file: ./my-credential-spec.json|
+```
+
+### depends_on
+
+Express dependency between services. Service dependencies cause the following
+behaviors:
+
+- `docker-compose up` starts services in dependency order. In the following
+  example, `db` and `redis` are started before `web`.
+- `docker-compose up SERVICE` automatically includes `SERVICE`'s
+  dependencies. In the example below, `docker-compose up web` also
+  creates and starts `db` and `redis`.
+- `docker-compose stop` stops services in dependency order. In the following
+  example, `web` is stopped before `db` and `redis`.
+
+Simple example:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    build: .
+    depends_on:
+      - db
+      - redis
+  redis:
+    image: redis
+  db:
+    image: postgres
+```
+
+> There are several things to be aware of when using `depends_on`:
+>
+> - `depends_on` does not wait for `db` and `redis` to be "ready" before
+>   starting `web` - only until they have been started. If you need to wait
+>   for a service to be ready, see [Controlling startup order](https://docs.docker.com/compose/startup-order/)
+>   for more on this problem and strategies for solving it.
+> - The `depends_on` option is ignored when
+>   [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy)
+>   with a version 3 Compose file.
+
+### deploy
+
+> Added in [version 3](compose-versioning.md#version-3) file format.
+
+Specify configuration related to the deployment and running of services. The following  
+sub-options only takes effect when deploying to a [swarm](https://docs.docker.com/engine/swarm/index) with
+[docker stack deploy](https://docs.docker.com/reference/cli/docker/stack/deploy), and is
+ignored by `docker-compose up` and `docker-compose run`, except for `resources`.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:alpine
+    deploy:
+      replicas: 6
+      placement:
+        max_replicas_per_node: 1
+      update_config:
+        parallelism: 2
+        delay: 10s
+      restart_policy:
+        condition: on-failure
+```
+
+Several sub-options are available:
+
+#### endpoint_mode
+
+> Added in [version 3.2](compose-versioning.md#version-32) file format.
+
+Specify a service discovery method for external clients connecting to a swarm.
+
+* `endpoint_mode: vip` - Docker assigns the service a virtual IP (VIP)
+that acts as the front end for clients to reach the service on a
+network. Docker routes requests between the client and available worker
+nodes for the service, without client knowledge of how many nodes
+are participating in the service or their IP addresses or ports.
+(This is the default.)
+
+* `endpoint_mode: dnsrr` -  DNS round-robin (DNSRR) service discovery does
+not use a single virtual IP. Docker sets up DNS entries for the service
+such that a DNS query for the service name returns a list of IP addresses,
+and the client connects directly to one of these. DNS round-robin is useful
+in cases where you want to use your own load balancer, or for Hybrid
+Windows and Linux applications.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  wordpress:
+    image: wordpress
+    ports:
+      - "8080:80"
+    networks:
+      - overlay
+    deploy:
+      mode: replicated
+      replicas: 2
+      endpoint_mode: vip
+
+  mysql:
+    image: mysql
+    volumes:
+       - db-data:/var/lib/mysql/data
+    networks:
+       - overlay
+    deploy:
+      mode: replicated
+      replicas: 2
+      endpoint_mode: dnsrr
+
+volumes:
+  db-data:
+
+networks:
+  overlay:
+```
+
+The options for `endpoint_mode` also work as flags on the swarm mode CLI command
+[docker service create](https://docs.docker.com/reference/cli/docker/service/create). For a
+quick list of all swarm related `docker` commands, see
+[Swarm mode CLI commands](https://docs.docker.com/engine/swarm/index#swarm-mode-key-concepts-and-tutorial).
+
+To learn more about service discovery and networking in swarm mode, see
+[Configure service discovery](https://docs.docker.com/engine/swarm/networking#configure-service-discovery)
+in the swarm mode topics.
+
+
+#### labels
+
+Specify labels for the service. These labels are *only* set on the service,
+and *not* on any containers for the service.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    image: web
+    deploy:
+      labels:
+        com.example.description: "This label will appear on the web service"
+```
+
+To set labels on containers instead, use the `labels` key outside of `deploy`:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    image: web
+    labels:
+      com.example.description: "This label will appear on all containers for the web service"
+```
+
+#### mode
+
+Either `global` (exactly one container per swarm node) or `replicated` (a
+specified number of containers). The default is `replicated`. (To learn more,
+see [Replicated and global services](https://docs.docker.com/engine/swarm/how-swarm-mode-works/services.#replicated-and-global-services)
+in the [swarm](https://docs.docker.com/engine/swarm/) topics.)
+
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  worker:
+    image: dockersamples/examplevotingapp_worker
+    deploy:
+      mode: global
+```
+
+#### placement
+
+Specify placement of constraints and preferences. See the docker service create
+documentation for a full description of the syntax and available types of
+[constraints](https://docs.docker.com/reference/cli/docker/service/create#constraint),
+[preferences](https://docs.docker.com/reference/cli/docker/service/create#placement-pref),
+and [specifying the maximum replicas per node](https://docs.docker.com/reference/cli/docker/service/create#replicas-max-per-node)
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  db:
+    image: postgres
+    deploy:
+      placement:
+        constraints:
+          - "node.role==manager"
+          - "engine.labels.operatingsystem==ubuntu 22.04"
+        preferences:
+          - spread: node.labels.zone
+```
+
+#### max_replicas_per_node
+
+> Added in [version 3.8](compose-versioning.md#version-38) file format.
+
+If the service is `replicated` (which is the default), [limit the number of replicas](https://docs.docker.com/reference/cli/docker/service/create#replicas-max-per-node)
+that can run on a node at any time.
+
+When there are more tasks requested than running nodes, an error
+`no suitable node (max replicas per node limit exceed)` is raised.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  worker:
+    image: dockersamples/examplevotingapp_worker
+    networks:
+      - frontend
+      - backend
+    deploy:
+      mode: replicated
+      replicas: 6
+      placement:
+        max_replicas_per_node: 1
+```
+
+#### replicas
+
+If the service is `replicated` (which is the default), specify the number of
+containers that should be running at any given time.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  worker:
+    image: dockersamples/examplevotingapp_worker
+    networks:
+      - frontend
+      - backend
+    deploy:
+      mode: replicated
+      replicas: 6
+```
+
+#### resources
+
+Configures resource constraints.
+
+> Changed in compose-file version 3
+>
+> The `resources` section replaces  the [older resource constraint options](compose-file-v2.md#cpu-and-other-resources)
+> in Compose files prior to version 3 (`cpu_shares`, `cpu_quota`, `cpuset`,
+> `mem_limit`, `memswap_limit`, `mem_swappiness`).
+> Refer to [Upgrading version 2.x to 3.x](compose-versioning.md#upgrading)
+> to learn about differences between version 2 and 3 of the compose-file format.
+
+Each of these is a single value, analogous to its
+[docker service create](https://docs.docker.com/reference/cli/docker/service/create) counterpart.
+
+In this general example, the `redis` service is constrained to use no more than
+50M of memory and `0.50` (50% of a single core) of available processing time (CPU),
+and has `20M` of memory and `0.25` CPU time reserved (as always available to it).
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:alpine
+    deploy:
+      resources:
+        limits:
+          cpus: '0.50'
+          memory: 50M
+        reservations:
+          cpus: '0.25'
+          memory: 20M
+```
+
+The topics below describe available options to set resource constraints on
+services or containers in a swarm.
+
+> Looking for options to set resources on non swarm mode containers?
+>
+> The options described here are specific to the
+`deploy` key and swarm mode. If you want to set resource constraints
+on non swarm deployments, use
+[Compose file format version 2 CPU, memory, and other resource options](compose-file-v2.md#cpu-and-other-resources).
+If you have further questions, refer to the discussion on the GitHub
+issue [docker/compose/4513](https://github.com/docker/compose/issues/4513).
+{ .important }
+
+##### Out Of Memory Exceptions (OOME)
+
+If your services or containers attempt to use more memory than the system has
+available, you may experience an Out Of Memory Exception (OOME) and a container,
+or the Docker daemon, might be killed by the kernel OOM killer. To prevent this
+from happening, ensure that your application runs on hosts with adequate memory
+and see [Understand the risks of running out of memory](https://docs.docker.com/config/containers/resource_constraints#understand-the-risks-of-running-out-of-memory).
+
+
+#### restart_policy
+
+Configures if and how to restart containers when they exit. Replaces
+[`restart`](compose-file-v2.md#orig-resources).
+
+- `condition`: One of `none`, `on-failure` or `any` (default: `any`).
+- `delay`: How long to wait between restart attempts, specified as a
+  [duration](#specifying-durations) (default: 5s).
+- `max_attempts`: How many times to attempt to restart a container before giving
+  up (default: never give up). If the restart does not succeed within the configured
+  `window`, this attempt doesn't count toward the configured `max_attempts` value.
+  For example, if `max_attempts` is set to '2', and the restart fails on the first
+  attempt, more than two restarts may be attempted.
+- `window`: How long to wait before deciding if a restart has succeeded,
+  specified as a [duration](#specifying-durations) (default:
+  decide immediately).
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:alpine
+    deploy:
+      restart_policy:
+        condition: on-failure
+        delay: 5s
+        max_attempts: 3
+        window: 120s
+```
+
+#### rollback_config
+
+> Added in [version 3.7](compose-versioning.md#version-37) file format.
+
+Configures how the service should be rollbacked in case of a failing
+update.
+
+- `parallelism`: The number of containers to rollback at a time. If set to 0, all containers rollback simultaneously.
+- `delay`: The time to wait between each container group's rollback (default 0s).
+- `failure_action`: What to do if a rollback fails. One of `continue` or `pause` (default `pause`)
+- `monitor`: Duration after each task update to monitor for failure `(ns|us|ms|s|m|h)` (default 5s) **Note**: Setting to 0 will use the default 5s.
+- `max_failure_ratio`: Failure rate to tolerate during a rollback (default 0).
+- `order`: Order of operations during rollbacks. One of `stop-first` (old task is stopped before starting new one), or `start-first` (new task is started first, and the running tasks briefly overlap) (default `stop-first`).
+
+#### update_config
+
+Configures how the service should be updated. Useful for configuring rolling
+updates.
+
+- `parallelism`: The number of containers to update at a time.
+- `delay`: The time to wait between updating a group of containers.
+- `failure_action`: What to do if an update fails. One of `continue`, `rollback`, or `pause`
+  (default: `pause`).
+- `monitor`: Duration after each task update to monitor for failure `(ns|us|ms|s|m|h)` (default 5s) **Note**: Setting to 0 will use the default 5s.
+- `max_failure_ratio`: Failure rate to tolerate during an update.
+- `order`: Order of operations during updates. One of `stop-first` (old task is stopped before starting new one), or `start-first` (new task is started first, and the running tasks briefly overlap) (default `stop-first`) **Note**: Only supported for v3.4 and higher.
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format.
+>
+> The `order` option is only supported by v3.4 and higher of the compose
+> file format.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  vote:
+    image: dockersamples/examplevotingapp_vote:before
+    depends_on:
+      - redis
+    deploy:
+      replicas: 2
+      update_config:
+        parallelism: 2
+        delay: 10s
+        order: stop-first
+```
+
+#### Not supported for `docker stack deploy`
+
+The following sub-options (supported for `docker-compose up` and `docker-compose run`) are _not supported_ for `docker stack deploy` or the `deploy` key.
+
+- [build](#build)
+- [cgroup_parent](#cgroup_parent)
+- [container_name](#container_name)
+- [devices](#devices)
+- [tmpfs](#tmpfs)
+- [external_links](#external_links)
+- [links](#links)
+- [network_mode](#network_mode)
+- [restart](#restart)
+- [security_opt](#security_opt)
+- [userns_mode](#userns_mode)
+
+> Tip
+>
+> See the section on [how to configure volumes for services, swarms, and docker-stack.yml
+> files](#volumes-for-services-swarms-and-stack-files). Volumes _are_ supported
+> but to work with swarms and services, they must be configured as named volumes
+> or associated with services that are constrained to nodes with access to the
+> requisite volumes.
+
+### devices
+
+List of device mappings.  Uses the same format as the `--device` docker
+client create option.
+
+```yaml
+devices:
+  - "/dev/ttyUSB0:/dev/ttyUSB0"
+```
+
+> Note when using docker stack deploy
+>
+> The `devices` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy)
+{ .important }
+
+### dns
+
+Custom DNS servers. Can be a single value or a list.
+
+```yaml
+dns: 8.8.8.8
+```
+
+```yaml
+dns:
+  - 8.8.8.8
+  - 9.9.9.9
+```
+
+### dns_search
+
+Custom DNS search domains. Can be a single value or a list.
+
+```yaml
+dns_search: example.com
+```
+
+```yaml
+dns_search:
+  - dc1.example.com
+  - dc2.example.com
+```
+
+### entrypoint
+
+Override the default entrypoint.
+
+```yaml
+entrypoint: /code/entrypoint.sh
+```
+
+The entrypoint can also be a list, in a manner similar to
+[dockerfile](https://docs.docker.com/reference/dockerfile#entrypoint):
+
+```yaml
+entrypoint: ["php", "-d", "memory_limit=-1", "vendor/bin/phpunit"]
+```
+
+> **Note**
+>
+> Setting `entrypoint` both overrides any default entrypoint set on the service's
+> image with the `ENTRYPOINT` Dockerfile instruction, *and* clears out any default
+> command on the image - meaning that if there's a `CMD` instruction in the
+> Dockerfile, it is ignored.
+
+### env_file
+
+Add environment variables from a file. Can be a single value or a list.
+
+If you have specified a Compose file with `docker-compose -f FILE`, paths in
+`env_file` are relative to the directory that file is in.
+
+Environment variables declared in the [environment](#environment) section
+_override_ these values &ndash; this holds true even if those values are
+empty or undefined.
+
+```yaml
+env_file: .env
+```
+
+```yaml
+env_file:
+  - ./common.env
+  - ./apps/web.env
+  - /opt/runtime_opts.env
+```
+
+Compose expects each line in an env file to be in `VAR=VAL` format. Lines
+beginning with `#` are treated as comments and are ignored. Blank lines are
+also ignored.
+
+```console
+# Set Rails/Rack environment
+RACK_ENV=development
+```
+
+Compose also recognizes inline comments, like in:
+
+```sh
+MY_VAR = value # this is a comment
+```
+
+To avoid interpreting "#" as an inline comment, use the quotation marks:
+
+```sh
+MY_VAR = "All the # inside are taken as part of the value"
+```
+
+> **Note**
+>
+> If your service specifies a [build](#build) option, variables defined in
+> environment files are _not_ automatically visible during the build. Use
+> the [args](#args) sub-option of `build` to define build-time environment
+> variables.
+
+The value of `VAL` is used as is and not modified at all. For example if the
+value is surrounded by quotes (as is often the case of shell variables), the
+quotes are included in the value passed to Compose.
+
+Keep in mind that _the order of files in the list is significant in determining
+the value assigned to a variable that shows up more than once_. The files in the
+list are processed from the top down. For the same variable specified in file
+`a.env` and assigned a different value in file `b.env`, if `b.env` is
+listed below (after), then the value from `b.env` stands. For example, given the
+following declaration in `docker-compose.yml`:
+
+```yaml
+services:
+  some-service:
+    env_file:
+      - a.env
+      - b.env
+```
+
+And the following files:
+
+```console
+# a.env
+VAR=1
+```
+
+and
+
+```console
+# b.env
+VAR=hello
+```
+
+`$VAR` is `hello`.
+
+### environment
+
+Add environment variables. You can use either an array or a dictionary. Any
+boolean values (true, false, yes, no) need to be enclosed in quotes to ensure
+they are not converted to True or False by the YML parser.
+
+Environment variables with only a key are resolved to their values on the
+machine Compose is running on, which can be helpful for secret or host-specific values.
+
+```yaml
+environment:
+  RACK_ENV: development
+  SHOW: 'true'
+  SESSION_SECRET:
+```
+
+```yaml
+environment:
+  - RACK_ENV=development
+  - SHOW=true
+  - SESSION_SECRET
+```
+
+> **Note**
+>
+> If your service specifies a [build](#build) option, variables defined in
+> `environment` are _not_ automatically visible during the build. Use the
+> [args](#args) sub-option of `build` to define build-time environment
+> variables.
+
+### expose
+
+Expose ports without publishing them to the host machine - they'll only be
+accessible to linked services. Only the internal port can be specified.
+
+```yaml
+expose:
+  - "3000"
+  - "8000"
+```
+
+### external_links
+
+Link to containers started outside this `docker-compose.yml` or even outside of
+Compose, especially for containers that provide shared or common services.
+`external_links` follow semantics similar to the legacy option `links` when
+specifying both the container name and the link alias (`CONTAINER:ALIAS`).
+
+```yaml
+external_links:
+  - redis_1
+  - project_db_1:mysql
+  - project_db_1:postgresql
+```
+
+> **Note**
+>
+> The externally-created  containers must be connected to at least one of the same
+> networks as the service that is linking to them. [Links](compose-file-v2.md#links)
+> are a legacy option. We recommend using [networks](#networks) instead.
+
+> Note when using docker stack deploy
+>
+> The `external_links` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy)
+{ .important }
+
+### extra_hosts
+
+Add hostname mappings. Use the same values as the docker client `--add-host` parameter.
+
+```yaml
+extra_hosts:
+  - "somehost:162.242.195.82"
+  - "otherhost:50.31.209.229"
+```
+
+An entry with the ip address and hostname is created in `/etc/hosts` inside containers for this service, e.g:
+
+```console
+162.242.195.82  somehost
+50.31.209.229   otherhost
+```
+
+### healthcheck
+
+Configure a check that's run to determine whether or not containers for this
+service are "healthy". See the docs for the
+[HEALTHCHECK Dockerfile instruction](https://docs.docker.com/reference/dockerfile#healthcheck)
+for details on how healthchecks work.
+
+```yaml
+healthcheck:
+  test: ["CMD", "curl", "-f", "http://localhost"]
+  interval: 1m30s
+  timeout: 10s
+  retries: 3
+  start_period: 2m
+```
+
+`interval`, `timeout` and `start_period` are specified as
+[durations](#specifying-durations).
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format.
+>
+> The `start_period` option was added in file format 3.4.
+
+`test` must be either a string or a list. If it's a list, the first item must be
+either `NONE`, `CMD` or `CMD-SHELL`. If it's a string, it's equivalent to
+specifying `CMD-SHELL` followed by that string.
+
+```yaml
+# Hit the local web app
+test: ["CMD", "curl", "-f", "http://localhost"]
+```
+
+As above, but wrapped in `/bin/sh`. Both forms below are equivalent.
+
+```yaml
+test: ["CMD-SHELL", "curl -f http://localhost || exit 1"]
+```
+
+```yaml
+test: curl -f https://localhost || exit 1
+```
+
+To disable any default healthcheck set by the image, you can use `disable: true`.
+This is equivalent to specifying `test: ["NONE"]`.
+
+```yaml
+healthcheck:
+  disable: true
+```
+
+### image
+
+Specify the image to start the container from. Can either be a repository/tag or
+a partial image ID.
+
+```yaml
+image: redis
+```
+```yaml
+image: ubuntu:22.04
+```
+```yaml
+image: tutum/influxdb
+```
+```yaml
+image: example-registry.com:4000/postgresql
+```
+```yaml
+image: a4bc65fd
+```
+
+If the image does not exist, Compose attempts to pull it, unless you have also
+specified [build](#build), in which case it builds it using the specified
+options and tags it with the specified tag.
+
+### init
+
+> Added in [version 3.7](compose-versioning.md#version-37) file format.
+
+Run an init inside the container that forwards signals and reaps processes.
+Set this option to `true` to enable this feature for the service.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    image: alpine:latest
+    init: true
+```
+
+> The default init binary that is used is [Tini](https://github.com/krallin/tini),
+> and is installed in `/usr/libexec/docker-init` on the daemon host. You can
+> configure the daemon to use a custom init binary through the
+> [`init-path` configuration option](/reference/cli/docker/dockerd/#daemon-configuration-file).
+
+### isolation
+
+Specify a container’s isolation technology. On Linux, the only supported value
+is `default`. On Windows, acceptable values are `default`, `process` and
+`hyperv`. Refer to the
+[Docker Engine docs](https://docs.docker.com/reference/cli/docker/container/run#isolation)
+for details.
+
+### labels
+
+Add metadata to containers using [Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either an array or a dictionary.
+
+It's recommended that you use reverse-DNS notation to prevent your labels from conflicting with those used by other software.
+
+```yaml
+labels:
+  com.example.description: "Accounting webapp"
+  com.example.department: "Finance"
+  com.example.label-with-empty-value: ""
+```
+
+```yaml
+labels:
+  - "com.example.description=Accounting webapp"
+  - "com.example.department=Finance"
+  - "com.example.label-with-empty-value"
+```
+
+### links
+
+>**Warning**
+>
+> The `--link` flag is a legacy feature of Docker. It may eventually be removed.
+> Unless you absolutely need to continue using it, we recommend that you use
+> [user-defined networks](https://docs.docker.com/compose/networking/)
+> to facilitate communication between two containers instead of using `--link`.
+>
+> One feature that user-defined networks do not support that you can do with
+> `--link` is sharing environmental variables between containers. However, you
+> can use other mechanisms such as volumes to share environment variables between
+> containers in a more controlled way.
+{ .warning }
+
+Link to containers in another service. Either specify both the service name and
+a link alias (`"SERVICE:ALIAS"`), or just the service name.
+
+```yaml
+web:
+  links:
+    - "db"
+    - "db:database"
+    - "redis"
+```
+
+Containers for the linked service are reachable at a hostname identical to
+the alias, or the service name if no alias was specified.
+
+Links are not required to enable services to communicate - by default,
+any service can reach any other service at that service’s name. (See also, the
+[Link containers section in Networking in Compose](https://docs.docker.com/compose/networking#link-containers).)
+
+Links also express dependency between services in the same way as
+[depends_on](#depends_on), so they determine the order of service startup.
+
+> **Note**
+>
+> If you define both links and [networks](#networks), services with
+> links between them must share at least one network in common to
+> communicate.
+
+> Note when using docker stack deploy
+>
+> The `links` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.comreference/cli/docker/stack/deploy)
+{ .important }
+
+### logging
+
+Logging configuration for the service.
+
+```yaml
+logging:
+  driver: syslog
+  options:
+    syslog-address: "tcp://192.168.0.42:123"
+```
+
+The `driver`  name specifies a logging driver for the service's
+containers, as with the ``--log-driver`` option for docker run
+([documented here](https://docs.docker.comconfig/containers/logging/configure)).
+
+The default value is json-file.
+
+```yaml
+driver: "json-file"
+```
+```yaml
+driver: "syslog"
+```
+```yaml
+driver: "none"
+```
+
+> **Note**
+>
+> Only the `json-file` and `journald` drivers make the logs available directly
+> from `docker-compose up` and `docker-compose logs`. Using any other driver
+> does not print any logs.
+
+Specify logging options for the logging driver with the ``options`` key, as with the ``--log-opt`` option for `docker run`.
+
+Logging options are key-value pairs. An example of `syslog` options:
+
+```yaml
+driver: "syslog"
+options:
+  syslog-address: "tcp://192.168.0.42:123"
+```
+
+The default driver [json-file](https://docs.docker.com/config/containers/logging/json-file), has options to limit the amount of logs stored. To do this, use a key-value pair for maximum storage size and maximum number of files:
+
+```yaml
+options:
+  max-size: "200k"
+  max-file: "10"
+```
+
+The example shown above would store log files until they reach a `max-size` of
+200kB, and then rotate them. The amount of individual log files stored is
+specified by the `max-file` value. As logs grow beyond the max limits, older log
+files are removed to allow storage of new logs.
+
+Here is an example `docker-compose.yml` file that limits logging storage:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  some-service:
+    image: some-service
+    logging:
+      driver: "json-file"
+      options:
+        max-size: "200k"
+        max-file: "10"
+```
+
+> Logging options available depend on which logging driver you use
+>
+> The above example for controlling log files and sizes uses options
+> specific to the [json-file driver](https://docs.docker.com/config/containers/logging/json-file).
+> These particular options are not available on other logging drivers.
+> For a full list of supported logging drivers and their options, refer to the
+> [logging drivers](https://docs.docker.com/config/containers/logging/configure) documentation.
+
+### network_mode
+
+Network mode. Use the same values as the docker client `--network` parameter, plus
+the special form `service:[service name]`.
+
+```yaml
+network_mode: "bridge"
+```
+```yaml
+network_mode: "host"
+```
+```yaml
+network_mode: "none"
+```
+```yaml
+network_mode: "service:[service name]"
+```
+```yaml
+network_mode: "container:[container name/id]"
+```
+
+> **Note**
+>
+> * This option is ignored when
+>   [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy).
+> * `network_mode: "host"` cannot be mixed with [links](#links).
+{ .important }
+
+### networks
+
+Networks to join, referencing entries under the
+[top-level `networks` key](#network-configuration-reference).
+
+```yaml
+services:
+  some-service:
+    networks:
+     - some-network
+     - other-network
+```
+
+#### aliases
+
+Aliases (alternative hostnames) for this service on the network. Other containers on the same network can use either the service name or this alias to connect to one of the service's containers.
+
+Since `aliases` is network-scoped, the same service can have different aliases on different networks.
+
+> **Note**
+>
+> A network-wide alias can be shared by multiple containers, and even by multiple
+> services. If it is, then exactly which container the name resolves to is not
+> guaranteed.
+
+The general format is shown here.
+
+```yaml
+services:
+  some-service:
+    networks:
+      some-network:
+        aliases:
+          - alias1
+          - alias3
+      other-network:
+        aliases:
+          - alias2
+```
+
+In the example below, three services are provided (`web`, `worker`, and `db`),
+along with two networks (`new` and `legacy`). The `db` service is reachable at
+the hostname `db` or `database` on the `new` network, and at `db` or `mysql` on
+the `legacy` network.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  web:
+    image: "nginx:alpine"
+    networks:
+      - new
+
+  worker:
+    image: "my-worker-image:latest"
+    networks:
+      - legacy
+
+  db:
+    image: mysql
+    networks:
+      new:
+        aliases:
+          - database
+      legacy:
+        aliases:
+          - mysql
+
+networks:
+  new:
+  legacy:
+```
+
+#### ipv4_address, ipv6_address
+
+Specify a static IP address for containers for this service when joining the network.
+
+The corresponding network configuration in the
+[top-level networks section](#network-configuration-reference) must have an
+`ipam` block with subnet configurations covering each static address.
+
+If you'd like to use IPv6, you must first ensure that the Docker daemon is configured to support IPv6.  See [Enable IPv6](https://docs.docker.com/config/daemon/ipv6) for detailed instructions. You can then access IPv6 addressing in a version 3.x Compose file by editing the `/etc/docker/daemon.json` to contain:
+`{"ipv6": true, "fixed-cidr-v6": "2001:db8:1::/64"}`
+
+Then, reload the docker daemon and edit docker-compose.yml to contain the following under the service:
+
+```yaml
+    sysctls:
+      - net.ipv6.conf.all.disable_ipv6=0
+```
+
+> The [`enable_ipv6`](compose-file-v2.md#enable_ipv6)
+> option is only available in a [version 2.x Compose file](compose-file-v2.md#ipv4_address-ipv6_address).
+> _IPv6 options do not currently work in swarm mode_.
+
+An example:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  app:
+    image: nginx:alpine
+    networks:
+      app_net:
+        ipv4_address: 172.16.238.10
+        ipv6_address: 2001:3984:3989::10
+
+networks:
+  app_net:
+    ipam:
+      driver: default
+      config:
+        - subnet: "172.16.238.0/24"
+        - subnet: "2001:3984:3989::/64"
+```
+
+### pid
+
+```yaml
+pid: "host"
+```
+
+Sets the PID mode to the host PID mode.  This turns on sharing between
+container and the host operating system the PID address space.  Containers
+launched with this flag can access and manipulate other
+containers in the bare-metal machine's namespace and vice versa.
+
+### ports
+
+Expose ports.
+
+> **Note**
+>
+> Port mapping is incompatible with `network_mode: host`
+
+> **Note**
+>
+> `docker-compose run` ignores `ports` unless you include `--service-ports`.
+
+#### Short syntax
+
+There are three options: 
+* Specify both ports (`HOST:CONTAINER`)
+* Specify just the container port (an ephemeral host port is chosen for the host port).
+* Specify the host IP address to bind to AND both ports (the default is 0.0.0.0, meaning all interfaces): (`IPADDR:HOSTPORT:CONTAINERPORT`). If HOSTPORT is empty (for example `127.0.0.1::80`), an ephemeral port is chosen to bind to on the host.
+
+> **Note**
+>
+> When mapping ports in the `HOST:CONTAINER` format, you may experience
+> erroneous results when using a container port lower than 60, because YAML
+> parses numbers in the format `xx:yy` as a base-60 value. For this reason,
+> we recommend always explicitly specifying your port mappings as strings.
+
+```yaml
+ports:
+  - "3000"
+  - "3000-3005"
+  - "8000:8000"
+  - "9090-9091:8080-8081"
+  - "49100:22"
+  - "127.0.0.1:8001:8001"
+  - "127.0.0.1:5000-5010:5000-5010"
+  - "127.0.0.1::5000"
+  - "6060:6060/udp"
+  - "12400-12500:1240"
+```
+
+#### Long syntax
+
+The long form syntax allows the configuration of additional fields that can't be
+expressed in the short form.
+
+- `target`: the port inside the container
+- `published`: the publicly exposed port
+- `protocol`: the port protocol (`tcp` or `udp`)
+- `mode`: `host` for publishing a host port on each node, or `ingress` for a swarm
+   mode port to be load balanced.
+
+```yaml
+ports:
+  - target: 80
+    published: 8080
+    protocol: tcp
+    mode: host
+```
+
+> Added in [version 3.2](compose-versioning.md#version-32) file format.
+>
+> The long syntax is new in the v3.2 file format.
+
+### profiles
+
+```yaml
+profiles: ["frontend", "debug"]
+profiles:
+  - frontend
+  - debug
+```
+
+`profiles` defines a list of named profiles for the service to be enabled under.
+When not set, the service is _always_ enabled. For the services that make up
+your core application you should omit `profiles` so they will always be started.
+
+Valid profile names follow the regex format `[a-zA-Z0-9][a-zA-Z0-9_.-]+`.
+
+See also [_Using profiles with Compose_](https://docs.docker.com/compose/profiles/) to learn more about
+profiles.
+
+### restart
+
+`no` is the default [restart policy](https://docs.docker.com/config/containers/start-containers-automatically#use-a-restart-policy), and it does not restart a container under
+any circumstance. When `always` is specified, the container always restarts. The
+`on-failure` policy restarts a container if the exit code indicates an
+on-failure error. `unless-stopped` always restarts a container, except when the
+container is stopped (manually or otherwise).
+
+    restart: "no"
+    restart: always
+    restart: on-failure
+    restart: unless-stopped
+
+> Note when using docker stack deploy
+>
+> The `restart` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy).
+{ .important }
+
+### secrets
+
+Grant access to secrets on a per-service basis using the per-service `secrets`
+configuration. Two different syntax variants are supported.
+
+> Note when using docker stack deploy
+>
+> The secret must already exist or be
+> [defined in the top-level `secrets` configuration](#secrets-configuration-reference)
+> of the compose file, or stack deployment fails.
+{ .important }
+
+For more information on secrets, see [secrets](https://docs.docker.com/engine/swarm/secrets).
+
+#### Short syntax
+
+The short syntax variant only specifies the secret name. This grants the
+container access to the secret and mounts it at `/run/secrets/<secret_name>`
+within the container. The source name and destination mountpoint are both set
+to the secret name.
+
+The following example uses the short syntax to grant the `redis` service
+access to the `my_secret` and `my_other_secret` secrets. The value of
+`my_secret` is set to the contents of the file `./my_secret.txt`, and
+`my_other_secret` is defined as an external resource, which means that it has
+already been defined in Docker, either by running the `docker secret create`
+command or by another stack deployment. If the external secret does not exist,
+the stack deployment fails with a `secret not found` error.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:latest
+    deploy:
+      replicas: 1
+    secrets:
+      - my_secret
+      - my_other_secret
+secrets:
+  my_secret:
+    file: ./my_secret.txt
+  my_other_secret:
+    external: true
+```
+
+#### Long syntax
+
+The long syntax provides more granularity in how the secret is created within
+the service's task containers.
+
+- `source`: The identifier of the secret as it is defined in this configuration.
+- `target`: The name of the file to be mounted in `/run/secrets/` in the
+  service's task containers. Defaults to `source` if not specified.
+- `uid` and `gid`: The numeric UID or GID that owns the file within
+  `/run/secrets/` in the service's task containers. Both default to `0` if not
+  specified.
+- `mode`: The permissions for the file to be mounted in `/run/secrets/`
+  in the service's task containers, in octal notation. For instance, `0444`
+  represents world-readable. The default in Docker 1.13.1 is `0000`, but it is
+  `0444` in newer versions. Secrets cannot be writable because they are mounted
+  in a temporary filesystem, so if you set the writable bit, it is ignored. The
+  executable bit can be set. If you aren't familiar with UNIX file permission
+  modes, you may find this
+  [permissions calculator](http://permissions-calculator.org/)
+  useful.
+
+The following example sets name of the `my_secret` to `redis_secret` within the
+container, sets the mode to `0440` (group-readable) and sets the user and group
+to `103`. The `redis` service does not have access to the `my_other_secret`
+secret.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  redis:
+    image: redis:latest
+    deploy:
+      replicas: 1
+    secrets:
+      - source: my_secret
+        target: redis_secret
+        uid: '103'
+        gid: '103'
+        mode: 0440
+secrets:
+  my_secret:
+    file: ./my_secret.txt
+  my_other_secret:
+    external: true
+```
+
+You can grant a service access to multiple secrets and you can mix long and
+short syntax. Defining a secret does not imply granting a service access to it.
+
+### security_opt
+
+Override the default labeling scheme for each container.
+
+```yaml
+security_opt:
+  - label:user:USER
+  - label:role:ROLE
+```
+
+> Note when using docker stack deploy
+>
+> The `security_opt` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy).
+{ .important }
+
+### stop_grace_period
+
+Specify how long to wait when attempting to stop a container if it doesn't
+handle SIGTERM (or whatever stop signal has been specified with
+[`stop_signal`](#stop_signal)), before sending SIGKILL. Specified
+as a [duration](#specifying-durations).
+
+```yaml
+stop_grace_period: 1s
+```
+
+```yaml
+stop_grace_period: 1m30s
+```
+
+By default, `stop` waits 10 seconds for the container to exit before sending
+SIGKILL.
+
+### stop_signal
+
+Sets an alternative signal to stop the container. By default `stop` uses
+SIGTERM. Setting an alternative signal using `stop_signal` causes
+`stop` to send that signal instead.
+
+```yaml
+stop_signal: SIGUSR1
+```
+
+### sysctls
+
+Kernel parameters to set in the container. You can use either an array or a
+dictionary.
+
+```yaml
+sysctls:
+  net.core.somaxconn: 1024
+  net.ipv4.tcp_syncookies: 0
+```
+
+```yaml
+sysctls:
+  - net.core.somaxconn=1024
+  - net.ipv4.tcp_syncookies=0
+```
+
+You can only use sysctls that are namespaced in the kernel. Docker does not
+support changing sysctls inside a container that also modify the host system.
+For an overview of supported sysctls, refer to
+[configure namespaced kernel parameters (sysctls) at runtime](https://docs.docker.com/reference/cli/docker/container/run#sysctl).
+
+> Note when using docker stack deploy
+>
+> This option requires Docker Engine 19.03 or up when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy).
+
+### tmpfs
+
+> Added in [version 3.6](compose-versioning.md#version-36) file format.
+
+Mount a temporary file system inside the container. Can be a single value or a list.
+
+```yaml
+tmpfs: /run
+```
+
+```yaml
+tmpfs:
+  - /run
+  - /tmp
+```
+
+> Note when using docker stack deploy
+>
+> This option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy)
+> with a (version 3-3.5) Compose file.
+
+Mount a temporary file system inside the container. Size parameter specifies the size
+of the tmpfs mount in bytes. Unlimited by default.
+
+```yaml
+- type: tmpfs
+  target: /app
+  tmpfs:
+    size: 1000
+```
+
+### ulimits
+
+Override the default ulimits for a container. You can either specify a single
+limit as an integer or soft/hard limits as a mapping.
+
+```yaml
+ulimits:
+  nproc: 65535
+  nofile:
+    soft: 20000
+    hard: 40000
+```
+
+### userns_mode
+
+```yaml
+userns_mode: "host"
+```
+
+Disables the user namespace for this service, if Docker daemon is configured with user namespaces.
+See [dockerd](https://docs.docker.com/engine/security/userns-remap#disable-namespace-remapping-for-a-container) for
+more information.
+
+> Note when using docker stack deploy
+>
+> The `userns_mode` option is ignored when
+> [deploying a stack in swarm mode](https://docs.docker.com/reference/cli/docker/stack/deploy).
+{ .important }
+
+### volumes
+
+Mount host paths or named volumes, specified as sub-options to a service.
+
+You can mount a host path as part of a definition for a single service, and
+there is no need to define it in the top level `volumes` key.
+
+But, if you want to reuse a volume across multiple services, then define a named
+volume in the [top-level `volumes` key](#volume-configuration-reference). Use
+named volumes with [services, swarms, and stack
+files](#volumes-for-services-swarms-and-stack-files).
+
+> Changed in [version 3](compose-versioning.md#version-3) file format.
+>
+> The top-level [volumes](#volume-configuration-reference) key defines
+> a named volume and references it from each service's `volumes` list. This
+> replaces `volumes_from` in earlier versions of the Compose file format.
+
+This example shows a named volume (`mydata`) being used by the `web` service,
+and a bind mount defined for a single service (first path under `db` service
+`volumes`). The `db` service also uses a named volume called `dbdata` (second
+path under `db` service `volumes`), but defines it using the old string format
+for mounting a named volume. Named volumes must be listed under the top-level
+`volumes` key, as shown.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    image: nginx:alpine
+    volumes:
+      - type: volume
+        source: mydata
+        target: /data
+        volume:
+          nocopy: true
+      - type: bind
+        source: ./static
+        target: /opt/app/static
+
+  db:
+    image: postgres:latest
+    volumes:
+      - "/var/run/postgres/postgres.sock:/var/run/postgres/postgres.sock"
+      - "dbdata:/var/lib/postgresql/data"
+
+volumes:
+  mydata:
+  dbdata:
+```
+
+> **Note**
+> 
+> For general information on volumes, refer to the [use volumes](https://docs.docker.comstorage/volumes)
+> and [volume plugins](/engine/extend/plugins_volume/) sections in the documentation.
+
+
+#### Short syntax
+
+The short syntax uses the generic `[SOURCE:]TARGET[:MODE]` format, where
+`SOURCE` can be either a host path or volume name. `TARGET` is the container
+path where the volume is mounted. Standard modes are `ro` for read-only
+and `rw` for read-write (default).
+
+You can mount a relative path on the host, which expands relative to
+the directory of the Compose configuration file being used. Relative paths
+should always begin with `.` or `..`.
+
+```yaml
+volumes:
+  # Just specify a path and let the Engine create a volume
+  - /var/lib/mysql
+
+  # Specify an absolute path mapping
+  - /opt/data:/var/lib/mysql
+
+  # Path on the host, relative to the Compose file
+  - ./cache:/tmp/cache
+
+  # User-relative path
+  - ~/configs:/etc/configs/:ro
+
+  # Named volume
+  - datavolume:/var/lib/mysql
+```
+
+#### Long syntax
+
+> Added in [version 3.2](compose-versioning.md#version-32) file format.
+
+The long form syntax allows the configuration of additional fields that can't be
+expressed in the short form.
+
+- `type`: the mount type `volume`, `bind`, `tmpfs` or `npipe`
+- `source`: the source of the mount, a path on the host for a bind mount, or the
+  name of a volume defined in the
+  [top-level `volumes` key](#volume-configuration-reference). Not applicable for a tmpfs mount.
+- `target`: the path in the container where the volume is mounted
+- `read_only`: flag to set the volume as read-only
+- `bind`: configure additional bind options
+  - `propagation`: the propagation mode used for the bind
+- `volume`: configure additional volume options
+  - `nocopy`: flag to disable copying of data from a container when a volume is
+    created
+- `tmpfs`: configure additional tmpfs options
+  - `size`: the size for the tmpfs mount in bytes
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    image: nginx:alpine
+    ports:
+      - "80:80"
+    volumes:
+      - type: volume
+        source: mydata
+        target: /data
+        volume:
+          nocopy: true
+      - type: bind
+        source: ./static
+        target: /opt/app/static
+
+networks:
+  webnet:
+
+volumes:
+  mydata:
+```
+
+> **Note**
+>
+> When creating bind mounts, using the long syntax requires the
+> referenced folder to be created beforehand. Using the short syntax
+> creates the folder on the fly if it doesn't exist.
+> See the [bind mounts documentation](https://docs.docker.com/storage/bind-mounts#differences-between--v-and---mount-behavior)
+> for more information.
+
+#### Volumes for services, swarms, and stack files
+
+> Note when using docker stack deploy
+>
+> When working with services, swarms, and `docker-stack.yml` files, keep in mind
+> that the tasks (containers) backing a service can be deployed on any node in a
+> swarm, and this may be a different node each time the service is updated.
+
+In the absence of having named volumes with specified sources, Docker creates an
+anonymous volume for each task backing a service. Anonymous volumes do not
+persist after the associated containers are removed.
+
+If you want your data to persist, use a named volume and a volume driver that
+is multi-host aware, so that the data is accessible from any node. Or, set
+constraints on the service so that its tasks are deployed on a node that has the
+volume present.
+
+As an example, the `docker-stack.yml` file for the
+[votingapp sample in Docker Labs](https://github.com/docker/labs/blob/master/beginner/chapters/votingapp.md)
+defines a service called `db` that runs a `postgres` database. It is configured
+as a named volume to persist the data on the swarm, _and_ is constrained to run
+only on `manager` nodes. Here is the relevant snip-it from that file:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  db:
+    image: postgres:9.4
+    volumes:
+      - db-data:/var/lib/postgresql/data
+    networks:
+      - backend
+    deploy:
+      placement:
+        constraints: [node.role == manager]
+```
+
+### domainname, hostname, ipc, mac\_address, privileged, read\_only, shm\_size, stdin\_open, tty, user, working\_dir
+
+Each of these is a single value, analogous to its
+[docker run](https://docs.docker.com/reference/cli/docker/container/run) counterpart. Note that `mac_address` is a legacy option.
+
+```yaml
+user: postgresql
+working_dir: /code
+
+domainname: foo.com
+hostname: foo
+ipc: host
+mac_address: 02:42:ac:11:65:43
+
+privileged: true
+
+
+read_only: true
+shm_size: 64M
+stdin_open: true
+tty: true
+```
+
+## Specifying durations
+
+Some configuration options, such as the `interval` and `timeout` sub-options for
+[`check`](#healthcheck), accept a duration as a string in a
+format that looks like this:
+
+    2.5s
+    10s
+    1m30s
+    2h32m
+    5h34m56s
+
+The supported units are `us`, `ms`, `s`, `m` and `h`.
+
+## Specifying byte values
+
+Some configuration options, such as the `shm_size` sub-option for
+[`build`](#build), accept a byte value as a string in a format
+that looks like this:
+
+    2b
+    1024kb
+    2048k
+    300m
+    1gb
+
+The supported units are `b`, `k`, `m` and `g`, and their alternative notation `kb`,
+`mb` and `gb`. Decimal values are not supported at this time.
+
+## Volume configuration reference
+
+While it is possible to declare [volumes](#volumes) on the fly as part of the
+service declaration, this section allows you to create named volumes that can be
+reused across multiple services (without relying on `volumes_from`), and are
+easily retrieved and inspected using the docker command line or API.
+See the [docker volume](https://docs.docker.com/reference/cli/docker/volume/create)
+subcommand documentation for more information.
+
+See [use volumes](https://docs.docker.com/storage/volumes) and [volume
+plugins](/engine/extend/plugins_volume/) for general information on volumes.
+
+Here's an example of a two-service setup where a database's data directory is
+shared with another service as a volume so that it can be periodically backed
+up:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  db:
+    image: db
+    volumes:
+      - data-volume:/var/lib/db
+  backup:
+    image: backup-service
+    volumes:
+      - data-volume:/var/lib/backup/data
+
+volumes:
+  data-volume:
+```
+
+An entry under the top-level `volumes` key can be empty, in which case it
+uses the default driver configured by the Engine (in most cases, this is the
+`local` driver). Optionally, you can configure it with the following keys:
+
+### driver
+
+Specify which volume driver should be used for this volume. Defaults to whatever
+driver the Docker Engine has been configured to use, which in most cases is
+`local`. If the driver is not available, the Engine returns an error when
+`docker-compose up` tries to create the volume.
+
+```yaml
+driver: foobar
+```
+
+### driver_opts
+
+Specify a list of options as key-value pairs to pass to the driver for this
+volume. Those options are driver-dependent - consult the driver's
+documentation for more information. Optional.
+
+```yaml
+volumes:
+  example:
+    driver_opts:
+      type: "nfs"
+      o: "addr=10.40.0.199,nolock,soft,rw"
+      device: ":/docker/example"
+```
+
+### external
+
+If set to `true`, specifies that this volume has been created outside of
+Compose. `docker-compose up` does not attempt to create it, and raises
+an error if it doesn't exist.
+
+For version 3.3 and below of the format, `external` cannot be used in
+conjunction with other volume configuration keys (`driver`, `driver_opts`,
+`labels`). This limitation no longer exists for
+[version 3.4](compose-versioning.md#version-34) and above.
+
+In the example below, instead of attempting to create a volume called
+`[projectname]_data`, Compose looks for an existing volume simply
+called `data` and mount it into the `db` service's containers.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  db:
+    image: postgres
+    volumes:
+      - data:/var/lib/postgresql/data
+
+volumes:
+  data:
+    external: true
+```
+
+> Deprecated in [version 3.4](compose-versioning.md#version-34) file format.
+>
+> external.name was deprecated in version 3.4 file format use `name` instead.
+{ .important }
+
+You can also specify the name of the volume separately from the name used to
+refer to it within the Compose file:
+
+```yaml
+volumes:
+  data:
+    external:
+      name: actual-name-of-volume
+```
+
+> Note when using docker stack deploy
+>
+> External volumes that do not exist _are created_ if you use [docker stack deploy](#deploy) 
+> to launch the app in [swarm mode](https://docs.docker.com/engine/swarm/index) (instead of
+> [docker compose up](https://docs.docker.com/reference/cli/docker/compose/up)). In swarm mode, a volume is
+> automatically created when it is defined by a service. As service tasks are
+> scheduled on new nodes, [swarmkit](https://github.com/docker/swarmkit/blob/master/README.md)
+> creates the volume on the local node. To learn more, see [moby/moby#29976](https://github.com/moby/moby/issues/29976).
+{ .important }
+
+### labels
+
+Add metadata to containers using
+[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either
+an array or a dictionary.
+
+It's recommended that you use reverse-DNS notation to prevent your labels from
+conflicting with those used by other software.
+
+```yaml
+labels:
+  com.example.description: "Database volume"
+  com.example.department: "IT/Ops"
+  com.example.label-with-empty-value: ""
+```
+
+```yaml
+labels:
+  - "com.example.description=Database volume"
+  - "com.example.department=IT/Ops"
+  - "com.example.label-with-empty-value"
+```
+
+### name
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format.
+
+Set a custom name for this volume. The name field can be used to reference
+volumes that contain special characters. The name is used as is
+and will **not** be scoped with the stack name.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+volumes:
+  data:
+    name: my-app-data
+```
+
+It can also be used in conjunction with the `external` property:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+volumes:
+  data:
+    external: true
+    name: my-app-data
+```
+
+## Network configuration reference
+
+The top-level `networks` key lets you specify networks to be created.
+
+* For a full explanation of Compose's use of Docker networking features and all
+  network driver options, see the [Networking guide](https://docs.docker.com/compose/networking/).
+* For [Docker Labs](https://github.com/docker/labs/blob/master/README.md)
+  tutorials on networking, start with [Designing Scalable, Portable Docker Container Networks](https://github.com/docker/labs/blob/master/networking/README.md)
+
+### driver
+
+Specify which driver should be used for this network.
+
+The default driver depends on how the Docker Engine you're using is configured,
+but in most instances it is `bridge` on a single host and `overlay` on a
+Swarm.
+
+The Docker Engine returns an error if the driver is not available.
+
+```yaml
+driver: overlay
+```
+
+#### bridge
+
+Docker defaults to using a `bridge` network on a single host. For examples of
+how to work with bridge networks, see the Docker Labs tutorial on
+[Bridge networking](https://github.com/docker/labs/blob/master/networking/A2-bridge-networking.md).
+
+#### overlay
+
+The `overlay` driver creates a named network across multiple nodes in a
+[swarm](https://docs.docker.com/engine/swarm/index).
+
+* For a working example of how to build and use an
+`overlay` network with a service in swarm mode, see the Docker Labs tutorial on
+[Overlay networking and service discovery](https://github.com/docker/labs/blob/master/networking/A3-overlay-networking.md).
+
+* For an in-depth look at how it works under the hood, see the
+networking concepts lab on the
+[Overlay Driver Network Architecture](https://github.com/docker/labs/blob/master/networking/concepts/06-overlay-networks.md).
+
+#### host or none
+
+Use the host's networking stack, or no networking. Equivalent to
+`docker run --net=host` or `docker run --net=none`. Only used if you use
+`docker stack` commands. If you use the `docker-compose` command,
+use [network_mode](#network_mode) instead.
+
+If you want to use a particular network on a common build, use `network` as
+mentioned in the second yaml file example.
+
+The syntax for using built-in networks such as `host` and `none` is a little
+different. Define an external network with the name `host` or `none` (that
+Docker has already created automatically) and an alias that Compose can use
+(`hostnet` or `nonet` in the following examples), then grant the service access to that
+network using the alias.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+services:
+  web:
+    networks:
+      hostnet: {}
+
+networks:
+  hostnet:
+    external: true
+    name: host
+```
+
+```yaml
+services:
+  web:
+    ...
+    build:
+      ...
+      network: host
+      context: .
+      ...
+```
+
+```yaml
+services:
+  web:
+    ...
+    networks:
+      nonet: {}
+
+networks:
+  nonet:
+    external: true
+    name: none
+```
+
+### driver_opts
+
+Specify a list of options as key-value pairs to pass to the driver for this
+network. Those options are driver-dependent - consult the driver's
+documentation for more information. Optional.
+
+```yaml
+driver_opts:
+  foo: "bar"
+  baz: 1
+```
+
+### attachable
+
+> Added in [version 3.2](compose-versioning.md#version-32) file format.
+
+Only used when the `driver` is set to `overlay`. If set to `true`, then
+standalone containers can attach to this network, in addition to services. If a
+standalone container attaches to an overlay network, it can communicate with
+services and standalone containers that are also attached to the overlay
+network from other Docker daemons.
+
+```yaml
+networks:
+  mynet1:
+    driver: overlay
+    attachable: true
+```
+
+### enable_ipv6
+
+Enable IPv6 networking on this network.
+
+> Not supported in Compose File version 3
+>
+> `enable_ipv6` requires you to use a version 2 Compose file, as this directive
+> is not yet supported in Swarm mode.
+{ .warning }
+
+### ipam
+
+Specify custom IPAM config. This is an object with several properties, each of
+which is optional:
+
+-   `driver`: Custom IPAM driver, instead of the default.
+-   `config`: A list with zero or more config blocks, each containing any of
+    the following keys:
+    - `subnet`: Subnet in CIDR format that represents a network segment
+
+A full example:
+
+```yaml
+ipam:
+  driver: default
+  config:
+    - subnet: 172.28.0.0/16
+```
+
+> **Note**
+>
+> Additional IPAM configurations, such as `gateway`, are only honored for version 2 at the moment.
+
+### internal
+
+By default, Docker also connects a bridge network to it to provide external
+connectivity. If you want to create an externally isolated overlay network,
+you can set this option to `true`.
+
+### labels
+
+Add metadata to containers using
+[Docker labels](https://docs.docker.com/config/labels-custom-metadata). You can use either
+an array or a dictionary.
+
+It's recommended that you use reverse-DNS notation to prevent your labels from
+conflicting with those used by other software.
+
+```yaml
+labels:
+  com.example.description: "Financial transaction network"
+  com.example.department: "Finance"
+  com.example.label-with-empty-value: ""
+```
+
+```yaml
+labels:
+  - "com.example.description=Financial transaction network"
+  - "com.example.department=Finance"
+  - "com.example.label-with-empty-value"
+```
+
+### external
+
+If set to `true`, specifies that this network has been created outside of
+Compose. `docker-compose up` does not attempt to create it, and raises
+an error if it doesn't exist.
+
+For version 3.3 and below of the format, `external` cannot be used in
+conjunction with other network configuration keys (`driver`, `driver_opts`,
+`ipam`, `internal`). This limitation no longer exists for
+[version 3.4](compose-versioning.md#version-34) and above.
+
+In the example below, `proxy` is the gateway to the outside world. Instead of
+attempting to create a network called `[projectname]_outside`, Compose
+looks for an existing network simply called `outside` and connect the `proxy`
+service's containers to it.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+
+services:
+  proxy:
+    build: ./proxy
+    networks:
+      - outside
+      - default
+  app:
+    build: ./app
+    networks:
+      - default
+
+networks:
+  outside:
+    external: true
+```
+
+> Deprecated in [version 3.5](compose-versioning.md#version-35) file format.
+>
+> external.name was deprecated in version 3.5 file format use `name` instead.
+{ .important }
+
+You can also specify the name of the network separately from the name used to
+refer to it within the Compose file:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+networks:
+  outside:
+    external:
+      name: actual-name-of-network
+```
+
+### name
+
+> Added in [version 3.5](compose-versioning.md#version-35) file format.
+
+Set a custom name for this network. The name field can be used to reference
+networks which contain special characters. The name is used as is
+and will **not** be scoped with the stack name.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+networks:
+  network1:
+    name: my-app-net
+```
+
+It can also be used in conjunction with the `external` property:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+networks:
+  network1:
+    external: true
+    name: my-app-net
+```
+
+## configs configuration reference
+
+The top-level `configs` declaration defines or references
+[configs](https://docs.docker.com/engine/swarm/configs) that can be granted to the services in
+this stack. The source of the config is either `file` or `external`.
+
+- `file`: The config is created with the contents of the file at the specified
+  path.
+- `external`: If set to true, specifies that this config has already been
+  created. Docker does not attempt to create it, and if it does not exist, a
+  `config not found` error occurs.
+- `name`: The name of the config object in Docker. This field can be used to
+  reference configs that contain special characters. The name is used as is
+  and will **not** be scoped with the stack name. Introduced in version 3.5
+  file format.
+- `driver` and `driver_opts`: The name of a custom secret driver, and driver-specific
+  options passed as key/value pairs. Introduced in version 3.8 file format, and
+  only supported when using `docker stack`.
+- `template_driver`: The name of the templating driver to use, which controls
+  whether and how to evaluate the secret payload as a template. If no driver
+  is set, no templating is used. The only driver currently supported is `golang`,
+  which uses a `golang`. Introduced in version 3.8 file format, and only supported
+  when using `docker stack`. Refer to [use a templated config](https://docs.docker.com/engine/swarm/configs#example-use-a-templated-config)
+  for a examples of templated configs.
+
+In this example, `my_first_config` is created (as
+`<stack_name>_my_first_config)`when the stack is deployed,
+and `my_second_config` already exists in Docker.
+
+```yaml
+configs:
+  my_first_config:
+    file: ./config_data
+  my_second_config:
+    external: true
+```
+
+Another variant for external configs is when the name of the config in Docker
+is different from the name that exists within the service. The following
+example modifies the previous one to use the external config called
+`redis_config`.
+
+```yaml
+configs:
+  my_first_config:
+    file: ./config_data
+  my_second_config:
+    external:
+      name: redis_config
+```
+
+You still need to [grant access to the config](#configs) to each service in the
+stack.
+
+
+
+## secrets configuration reference
+
+The top-level `secrets` declaration defines or references
+[secrets](https://docs.docker.com/engine/swarm/secrets) that can be granted to the services in
+this stack. The source of the secret is either `file` or `external`.
+
+- `file`: The secret is created with the contents of the file at the specified
+  path.
+- `external`: If set to true, specifies that this secret has already been
+  created. Docker does not attempt to create it, and if it does not exist, a
+  `secret not found` error occurs.
+- `name`: The name of the secret object in Docker. This field can be used to
+  reference secrets that contain special characters. The name is used as is
+  and will **not** be scoped with the stack name. Introduced in version 3.5
+  file format.
+- `template_driver`: The name of the templating driver to use, which controls
+  whether and how to evaluate the secret payload as a template. If no driver
+  is set, no templating is used. The only driver currently supported is `golang`,
+  which uses a `golang`. Introduced in version 3.8 file format, and only
+  supported when using `docker stack`.
+
+In this example, `my_first_secret` is created as
+`<stack_name>_my_first_secret` when the stack is deployed,
+and `my_second_secret` already exists in Docker.
+
+```yaml
+secrets:
+  my_first_secret:
+    file: ./secret_data
+  my_second_secret:
+    external: true
+```
+
+Another variant for external secrets is when the name of the secret in Docker
+is different from the name that exists within the service. The following
+example modifies the previous one to use the external secret called
+`redis_secret`.
+
+### Compose File v3.5 and above
+
+```yaml
+secrets:
+  my_first_secret:
+    file: ./secret_data
+  my_second_secret:
+    external: true
+    name: redis_secret
+```
+
+### Compose File v3.4 and under
+
+```yaml
+  my_second_secret:
+    external:
+      name: redis_secret
+```
+
+You still need to [grant access to the secrets](#secrets) to each service in the
+stack.
+
+## Variable substitution
+
+Your configuration options can contain environment variables. Compose uses the
+variable values from the shell environment in which `docker compose` is run. For
+example, suppose the shell contains `POSTGRES_VERSION=9.3` and you supply this
+configuration:
+
+```yaml
+db:
+  image: "postgres:${POSTGRES_VERSION}"
+```
+
+When you run `docker compose up` with this configuration, Compose looks for the
+`POSTGRES_VERSION` environment variable in the shell and substitutes its value
+in. For this example, Compose resolves the `image` to `postgres:9.3` before
+running the configuration.
+
+If an environment variable is not set, Compose substitutes with an empty
+string. In the example above, if `POSTGRES_VERSION` is not set, the value for
+the `image` option is `postgres:`.
+
+You can set default values for environment variables using a
+`.env` file, which Compose automatically looks for in
+project directory (parent folder of your Compose file). 
+Values set in the shell environment override those set in the `.env` file.
+
+> Note when using docker stack deploy
+>
+> The `.env file` feature only works when you use the `docker compose up` command
+> and does not work with `docker stack deploy`.
+{ .important }
+
+Both `$VARIABLE` and `${VARIABLE}` syntax are supported. Additionally when using
+the [2.1 file format](compose-versioning.md#version-21), it is possible to
+provide inline default values using typical shell syntax:
+
+- `${VARIABLE:-default}` evaluates to `default` if `VARIABLE` is unset or
+  empty in the environment.
+- `${VARIABLE-default}` evaluates to `default` only if `VARIABLE` is unset
+  in the environment.
+
+Similarly, the following syntax allows you to specify mandatory variables:
+
+- `${VARIABLE:?err}` exits with an error message containing `err` if
+  `VARIABLE` is unset or empty in the environment.
+- `${VARIABLE?err}` exits with an error message containing `err` if
+  `VARIABLE` is unset in the environment.
+
+Other extended shell-style features, such as `${VARIABLE/foo/bar}`, are not
+supported.
+
+You can use a `$$` (double-dollar sign) when your configuration needs a literal
+dollar sign. This also prevents Compose from interpolating a value, so a `$$`
+allows you to refer to environment variables that you don't want processed by
+Compose.
+
+```yaml
+web:
+  build: .
+  command: "$$VAR_NOT_INTERPOLATED_BY_COMPOSE"
+```
+
+If you forget and use a single dollar sign (`$`), Compose interprets the value
+as an environment variable and warns you:
+
+```console
+The VAR_NOT_INTERPOLATED_BY_COMPOSE is not set. Substituting an empty string.
+```
+
+## Extension fields
+
+> Added in [version 3.4](compose-versioning.md#version-34) file format.
+
+It is possible to re-use configuration fragments using extension fields. Those
+special fields can be of any format as long as they are located at the root of
+your Compose file and their name start with the `x-` character sequence.
+
+> **Note**
+>
+> Starting with the 3.7 format (for the 3.x series) and 2.4 format
+> (for the 2.x series), extension fields are also allowed at the root
+> of service, volume, network, config and secret definitions.
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-custom:
+  items:
+    - a
+    - b
+  options:
+    max-size: '12m'
+  name: "custom"
+```
+
+The contents of those fields are ignored by Compose, but they can be
+inserted in your resource definitions using [YAML anchors](https://yaml.org/spec/1.2/spec.html#id2765878).
+For example, if you want several of your services to use the same logging
+configuration:
+
+```yaml
+logging:
+  options:
+    max-size: '12m'
+    max-file: '5'
+  driver: json-file
+```
+
+You may write your Compose file as follows:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-logging:
+  &default-logging
+  options:
+    max-size: '12m'
+    max-file: '5'
+  driver: json-file
+
+services:
+  web:
+    image: myapp/web:latest
+    logging: *default-logging
+  db:
+    image: mysql:latest
+    logging: *default-logging
+```
+
+It is also possible to partially override values in extension fields using
+the [YAML merge type](https://yaml.org/type/merge.html). For example:
+
+```yaml
+version: "{{% param "compose_file_v3" %}}"
+x-volumes:
+  &default-volume
+  driver: foobar-storage
+
+services:
+  web:
+    image: myapp/web:latest
+    volumes: ["vol1", "vol2", "vol3"]
+volumes:
+  vol1: *default-volume
+  vol2:
+    << : *default-volume
+    name: volume02
+  vol3:
+    << : *default-volume
+    driver: default
+    name: volume-local
+```
diff --git a/docs/Compose file reference/version-3.md b/docs/Compose file reference/version-3.md
deleted file mode 100644
index e69de29bb2d..00000000000
diff --git a/docs/README.md b/docs/README.md
deleted file mode 100644
index accc7c23e42..00000000000
--- a/docs/README.md
+++ /dev/null
@@ -1,14 +0,0 @@
-# The docs have been moved!
-
-The documentation for Compose has been merged into
-[the general documentation repo](https://github.com/docker/docker.github.io).
-
-The docs for Compose are now here:
-https://github.com/docker/docker.github.io/tree/master/compose
-
-Please submit pull requests for unreleased features/changes on the `master` branch (https://github.com/docker/docker.github.io/tree/master), please prefix the PR title with `[WIP]` to indicate that it relates to an unreleased change.
-
-If you submit a PR to this codebase that has a docs impact, create a second docs PR on `docker.github.io`. Use the docs PR template provided.
-
-As always, the docs remain open-source and we appreciate your feedback and
-pull requests!