Add markdown CI (kubernetes-sigs#5380)

Author: Miouge1

Diff for: .gitlab-ci/lint.yml

@@ -47,3 +47,11 @@ tox-inventory-builder:
     - cd contrib/inventory_builder && tox
   when: manual
   except: ['triggers', 'master']
+
+markdownlint:
+  stage: unit-tests
+  image: node
+  before_script:
+    - npm install -g markdownlint-cli
+  script:
+    - markdownlint README.md docs --ignore docs/_sidebar.md

Diff for: .markdownlint.yaml

@@ -0,0 +1,2 @@
+---
+MD013: false

Diff for: README.md

@@ -1,9 +1,7 @@
-Ansible variables
-===============
+# Ansible variables
 
+## Inventory
 
-Inventory
--------------
 The inventory is composed of 3 groups:
 
 * **kube-node** : list of kubernetes nodes where the pods will run.
@@ -14,7 +12,7 @@ Note: do not modify the children of _k8s-cluster_, like putting
 the _etcd_ group into the _k8s-cluster_, unless you are certain
 to do that and you have it fully contained in the latter:
 
-```
+```ShellSession
 k8s-cluster ⊂ etcd => kube-node ∩ etcd = etcd
 ```
 
@@ -32,7 +30,7 @@ There are also two special groups:
 
 Below is a complete inventory example:
 
-```
+```ini
 ## Configure 'ip' variable to bind kubernetes services on a
 ## different ip than the default iface
 node1 ansible_host=95.54.0.12 ip=10.3.0.1
@@ -63,8 +61,7 @@ kube-node
 kube-master
 ```
 
-Group vars and overriding variables precedence
-----------------------------------------------
+## Group vars and overriding variables precedence
 
 The group variables to control main deployment options are located in the directory ``inventory/sample/group_vars``.
 Optional variables are located in the `inventory/sample/group_vars/all.yml`.
@@ -73,7 +70,7 @@ Mandatory variables that are common for at least one role (or a node group) can
 There are also role vars for docker, kubernetes preinstall and master roles.
 According to the [ansible docs](http://docs.ansible.com/ansible/playbooks_variables.html#variable-precedence-where-should-i-put-a-variable),
 those cannot be overridden from the group vars. In order to override, one should use
-the `-e ` runtime flags (most simple way) or other layers described in the docs.
+the `-e` runtime flags (most simple way) or other layers described in the docs.
 
 Kubespray uses only a few layers to override things (or expect them to
 be overridden for roles):
@@ -97,8 +94,8 @@ block vars (only for tasks in block) | Kubespray overrides for internal roles' l
 task vars (only for the task) | Unused for roles, but only for helper scripts
 **extra vars** (always win precedence) | override with ``ansible-playbook -e @foo.yml``
 
-Ansible tags
-------------
+## Ansible tags
+
 The following tags are defined in playbooks:
 
 |                 Tag name | Used for
@@ -145,36 +142,40 @@ Note: Use the ``bash scripts/gen_tags.sh`` command to generate a list of all
 tags found in the codebase. New tags will be listed with the empty "Used for"
 field.
 
-Example commands
-----------------
+## Example commands
+
 Example command to filter and apply only DNS configuration tasks and skip
 everything else related to host OS configuration and downloading images of containers:
 
-```
+```ShellSession
 ansible-playbook -i inventory/sample/hosts.ini cluster.yml --tags preinstall,facts --skip-tags=download,bootstrap-os
 ```
+
 And this play only removes the K8s cluster DNS resolver IP from hosts' /etc/resolv.conf files:
-```
+
+```ShellSession
 ansible-playbook -i inventory/sample/hosts.ini -e dns_mode='none' cluster.yml --tags resolvconf
 ```
+
 And this prepares all container images locally (at the ansible runner node) without installing
 or upgrading related stuff or trying to upload container to K8s cluster nodes:
-```
+
+```ShellSession
 ansible-playbook -i inventory/sample/hosts.ini cluster.yml \
     -e download_run_once=true -e download_localhost=true \
     --tags download --skip-tags upload,upgrade
 ```
 
 Note: use `--tags` and `--skip-tags` wise and only if you're 100% sure what you're doing.
 
-Bastion host
---------------
+## Bastion host
+
 If you prefer to not make your nodes publicly accessible (nodes with private IPs only),
 you can use a so called *bastion* host to connect to your nodes. To specify and use a bastion,
 simply add a line to your inventory, where you have to replace x.x.x.x with the public IP of the
 bastion host.
 
-```
+```ShellSession
 [bastion]
 bastion ansible_host=x.x.x.x
 ```

Diff for: docs/ansible.md

@@ -1,6 +1,7 @@
-## Architecture compatibility
+# Architecture compatibility
 
 The following table shows the impact of the CPU architecture on compatible features:
+
 - amd64: Cluster using only x86/amd64 CPUs
 - arm64: Cluster using only arm64 CPUs
 - amd64 + arm64: Cluster with a mix of x86/amd64 and arm64 CPUs

Diff for: docs/arch.md

@@ -1,23 +1,22 @@
-Atomic host bootstrap
-=====================
+# Atomic host bootstrap
 
 Atomic host testing has been done with the network plugin flannel. Change the inventory var `kube_network_plugin: flannel`.
 
 Note: Flannel is the only plugin that has currently been tested with atomic
 
-### Vagrant
+## Vagrant
 
-* For bootstrapping with Vagrant, use box centos/atomic-host or fedora/atomic-host 
+* For bootstrapping with Vagrant, use box centos/atomic-host or fedora/atomic-host
 * Update VagrantFile variable `local_release_dir` to `/var/vagrant/temp`.
 * Update `vm_memory = 2048` and `vm_cpus = 2`
 * Networking on vagrant hosts has to be brought up manually once they are booted.
 
-    ```
+    ```ShellSession
     vagrant ssh
     sudo /sbin/ifup enp0s8
     ```
 
-* For users of vagrant-libvirt download centos/atomic-host qcow2 format from https://wiki.centos.org/SpecialInterestGroup/Atomic/Download/
-* For users of vagrant-libvirt download fedora/atomic-host qcow2 format from https://dl.fedoraproject.org/pub/alt/atomic/stable/
+* For users of vagrant-libvirt download centos/atomic-host qcow2 format from <https://wiki.centos.org/SpecialInterestGroup/Atomic/Download/>
+* For users of vagrant-libvirt download fedora/atomic-host qcow2 format from <https://dl.fedoraproject.org/pub/alt/atomic/stable/>
 
 Then you can proceed to [cluster deployment](#run-deployment)

Diff for: docs/atomic.md

@@ -1,5 +1,4 @@
-AWS
-===============
+# AWS
 
 To deploy kubespray on [AWS](https://aws.amazon.com/) uncomment the `cloud_provider` option in `group_vars/all.yml` and set it to `'aws'`. Refer to the [Kubespray Configuration](#kubespray-configuration) for customizing the provider.
 
@@ -13,11 +12,13 @@ The next step is to make sure the hostnames in your `inventory` file are identic
 
 You can now create your cluster!
 
-### Dynamic Inventory ###
+## Dynamic Inventory
+
 There is also a dynamic inventory script for AWS that can be used if desired. However, be aware that it makes some certain assumptions about how you'll create your inventory. It also does not handle all use cases and groups that we may use as part of more advanced deployments. Additions welcome.
 
 This will produce an inventory that is passed into Ansible that looks like the following:
-```
+
+```json
 {
   "_meta": {
     "hostvars": {
@@ -48,15 +49,18 @@ This will produce an inventory that is passed into Ansible that looks like the f
 ```
 
 Guide:
+
 - Create instances in AWS as needed.
 - Either during or after creation, add tags to the instances with a key of `kubespray-role` and a value of `kube-master`, `etcd`, or `kube-node`. You can also share roles like `kube-master, etcd`
 - Copy the `kubespray-aws-inventory.py` script from `kubespray/contrib/aws_inventory` to the `kubespray/inventory` directory.
 - Set the following AWS credentials and info as environment variables in your terminal:
-```
+
+```ShellSession
 export AWS_ACCESS_KEY_ID="xxxxx"
 export AWS_SECRET_ACCESS_KEY="yyyyy"
 export REGION="us-east-2"
 ```
+
 - We will now create our cluster. There will be either one or two small changes. The first is that we will specify `-i inventory/kubespray-aws-inventory.py` as our inventory script. The other is conditional. If your AWS instances are public facing, you can set the `VPC_VISIBILITY` variable to `public` and that will result in public IP and DNS names being passed into the inventory. This causes your cluster.yml command to look like `VPC_VISIBILITY="public" ansible-playbook ... cluster.yml`
 
 ## Kubespray configuration
@@ -75,4 +79,3 @@ aws_kubernetes_cluster_id|string|KubernetesClusterID is the cluster id we'll use
 aws_disable_security_group_ingress|bool|The aws provider creates an inbound rule per load balancer on the node security group. However, this can run into the AWS security group rule limit of 50 if many LoadBalancers are created. This flag disables the automatic ingress creation. It requires that the user has setup a rule that allows inbound traffic on kubelet ports from the local VPC subnet (so load balancers can access it). E.g. 10.82.0.0/16 30000-32000.
 aws_elb_security_group|string|Only in Kubelet version >= 1.7 : AWS has a hard limit of 500 security groups. For large clusters creating a security group for each ELB can cause the max number of security groups to be reached. If this is set instead of creating a new Security group for each ELB this security group will be used instead.
 aws_disable_strict_zone_check|bool|During the instantiation of an new AWS cloud provider, the detected region is validated against a known set of regions. In a non-standard, AWS like environment (e.g. Eucalyptus), this check may be undesirable.  Setting this to true will disable the check and provide a warning that the check was skipped.  Please note that this is an experimental feature and work-in-progress for the moment.
-

Diff for: docs/aws.md

@@ -1,46 +1,50 @@
-Azure
-===============
+# Azure
 
 To deploy Kubernetes on [Azure](https://azure.microsoft.com) uncomment the `cloud_provider` option in `group_vars/all.yml` and set it to `'azure'`.
 
 All your instances are required to run in a resource group and a routing table has to be attached to the subnet your instances are in.
 
 Not all features are supported yet though, for a list of the current status have a look [here](https://github.com/colemickens/azure-kubernetes-status)
 
-### Parameters
+## Parameters
 
 Before creating the instances you must first set the `azure_` variables in the `group_vars/all.yml` file.
 
-All of the values can be retrieved using the azure cli tool which can be downloaded here: https://docs.microsoft.com/en-gb/azure/xplat-cli-install
+All of the values can be retrieved using the azure cli tool which can be downloaded here: <https://docs.microsoft.com/en-gb/azure/xplat-cli-install>
 After installation you have to run `azure login` to get access to your account.
 
+### azure\_tenant\_id + azure\_subscription\_id
 
-#### azure\_tenant\_id + azure\_subscription\_id
 run `azure account show` to retrieve your subscription id and tenant id:
 `azure_tenant_id` -> Tenant ID field
 `azure_subscription_id` -> ID field
 
+### azure\_location
 
-#### azure\_location
 The region your instances are located, can be something like `westeurope` or `westcentralus`. A full list of region names can be retrieved via `azure location list`
 
+### azure\_resource\_group
 
-#### azure\_resource\_group
 The name of the resource group your instances are in, can be retrieved via `azure group list`
 
-#### azure\_vnet\_name
+### azure\_vnet\_name
+
 The name of the virtual network your instances are in, can be retrieved via `azure network vnet list`
 
-#### azure\_subnet\_name
+### azure\_subnet\_name
+
 The name of the subnet your instances are in, can be retrieved via `azure network vnet subnet list --resource-group RESOURCE_GROUP --vnet-name VNET_NAME`
 
-#### azure\_security\_group\_name
+### azure\_security\_group\_name
+
 The name of the network security group your instances are in, can be retrieved via `azure network nsg list`
 
-#### azure\_aad\_client\_id + azure\_aad\_client\_secret
+### azure\_aad\_client\_id + azure\_aad\_client\_secret
+
 These will have to be generated first:
+
 - Create an Azure AD Application with:
-`azure ad app create --display-name kubernetes --identifier-uris http://kubernetes --homepage http://example.com --password CLIENT_SECRET` 
+`azure ad app create --display-name kubernetes --identifier-uris http://kubernetes --homepage http://example.com --password CLIENT_SECRET`
 display name, identifier-uri, homepage and the password can be chosen
 Note the AppId in the output.
 - Create Service principal for the application with:
@@ -51,24 +55,28 @@ This is the AppId from the last command
 
 azure\_aad\_client\_id must be set to the AppId, azure\_aad\_client\_secret is your chosen secret.
 
-#### azure\_loadbalancer\_sku
+### azure\_loadbalancer\_sku
+
 Sku of Load Balancer and Public IP. Candidate values are: basic and standard.
 
-#### azure\_exclude\_master\_from\_standard\_lb
+### azure\_exclude\_master\_from\_standard\_lb
+
 azure\_exclude\_master\_from\_standard\_lb excludes master nodes from `standard` load balancer.
 
-#### azure\_disable\_outbound\_snat
+### azure\_disable\_outbound\_snat
+
 azure\_disable\_outbound\_snat disables the outbound SNAT for public load balancer rules. It should only be set when azure\_exclude\_master\_from\_standard\_lb is `standard`.
- 
-#### azure\_primary\_availability\_set\_name
-(Optional) The name of the availability set that should be used as the load balancer backend .If this is set, the Azure 
-cloudprovider will only add nodes from that availability set to the load balancer backend pool. If this is not set, and 
-multiple agent pools (availability sets) are used, then the cloudprovider will try to add all nodes to a single backend 
+
+### azure\_primary\_availability\_set\_name
+
+(Optional) The name of the availability set that should be used as the load balancer backend .If this is set, the Azure
+cloudprovider will only add nodes from that availability set to the load balancer backend pool. If this is not set, and
+multiple agent pools (availability sets) are used, then the cloudprovider will try to add all nodes to a single backend
 pool which is forbidden. In other words, if you use multiple agent pools (availability sets), you MUST set this field.
 
-#### azure\_use\_instance\_metadata
-Use instance metadata service where possible
+### azure\_use\_instance\_metadata
 
+Use instance metadata service where possible
 
 ## Provisioning Azure with Resource Group Templates