[Express] Getting started guide (#3904)

* Reinstate Express GS guide.

* Fix express links. add add-database page.

* Doc review

---------

Co-authored-by: Anouck Colson <[email protected]>

Author: chadwcarlson

sites/upsun/src/get-started/stacks/express.md

@@ -0,0 +1,344 @@
+---
+title: Deploying Express on Upsun
+sectionBefore: Javascript/Node.js
+sidebarTitle: Express
+weight: -100
+layout: single
+description: |
+    Complete the last required steps to successfully deploy Express on {{% vendor/name %}}.
+---
+
+{{< note title="Note" theme="info" >}}
+
+Before you start, check out the [{{% vendor/name %}} demo app](https://console.upsun.com/projects/create-project) and the main [Getting started guide](/get-started/here/_index.md).
+They provide all of the core concepts and common commands you need to know before using the materials below.
+
+{{< /note >}}
+
+{{% guides/requirements name="Express" %}}
+
+## 1. Create an Express app
+
+To create your Express app, follow these steps.
+
+1. Follow the Express [installation guide](https://expressjs.com/en/starter/installing.html).
+   To fast track the process, run the following commands:
+
+   ```bash {location="Terminal"}
+   mkdir my-express-app && cd my-express-app
+   npx express-generator
+   ```
+
+2. To initialize the local Git repository and commit local files, run the following commands:
+
+   ```bash {location="Terminal"}
+   git init
+   echo "node_modules" >> .gitignore
+   git add .
+   git commit -m "Init Express application."
+   ```
+
+{{< note theme="info" >}}
+You can view your running app locally by installing dependencies (`npm install`) and running `npm run dev`.
+The local server is visible at `localhost:3000`.
+{{< /note >}}
+
+## 2. Create a new project
+
+To create a project on {{% vendor/name %}},
+follow these steps.
+
+{{< note title="Remember" >}}
+After creating your {{% vendor/name %}} project, copy your new **project ID** for later use.
+{{< /note >}}
+
+{{< codetabs >}}
++++
+title=Using the CLI
++++
+To create a new project with the {{% vendor/name %}} CLI, use the following command and follow the prompts:
+
+```bash {location="Terminal"}
+{{% vendor/cli %}} project:create
+```
+
+{{< note >}}
+
+When creating a new project using the {{% vendor/name %}} CLI command `project:create`,
+you are asked if you want to set the local remote to your new project. Enter **Yes (y)**.
+
+Your local source code is automatically linked to your newly created {{% vendor/name %}} project
+through the creation of a `.{{% vendor/cli %}}/local/project.yaml`.
+This file contains the corresponding `<projectId>` for the {{% vendor/name %}} CLI to use,
+and sets a Git remote to `{{% vendor/cli %}}`.
+
+{{< /note >}}
+
+<--->
++++
+title=Using the Console
++++
+
+1. Create an organization or select an existing one.
+
+2. Click **Create from scratch**.
+
+3. Fill in details like the project name and [region](/development/regions.md).
+   
+   {{% note %}}
+
+   You can define resources for your project later on, after your first push.
+
+   {{% /note %}}
+
+4. To link your local source code to your new {{% vendor/name %}} project,
+   run the following command:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} project:set-remote <projectId>
+   ```
+
+   This command adds a new remote called `{{% vendor/cli %}}` to your local Git repository,
+   which is equivalent to the following commands:
+
+   ```bash {location="Terminal"}
+   git remote
+   origin
+   {{% vendor/cli %}}
+   ```
+
+   It also creates a new `.{{% vendor/cli %}}/local/project.yaml` file that contains the `<projectId>`
+   for the `{{% vendor/cli %}}` CLI to use.
+
+   {{< note theme="info" title="Tip" >}}
+
+   If you forget your `<projectId>`, run the following command and find your project in the list:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} project:list
+   ```
+   {{< /note >}}
+
+{{< /codetabs >}}
+
+## 3. Choose your Git workflow
+
+You can use {{% vendor/name %}} projects as a classic Git repository,
+where you are able to push your source code in different ways,
+using either the Git CLI or the {{% vendor/name %}} CLI.
+You can choose which way —or Git workflow— you want to use for your project from the following options:
+
+- Your project source code is **hosted on a {{% vendor/name %}} Git repository**
+- Your project source code is **hosted on your own GitHub repository**
+
+{{< codetabs >}}
++++
+title={{% vendor/name %}} Git repository
++++
+For the rest of this guide, you will use the normal Git workflow (`git add . && git commit -m "message" && git push {{% vendor/cli %}}`) to commit your source code changes to Git history.
+You will also use the {{% vendor/name %}} CLI to deploy your [{{% vendor/name %}} environment](/environments.html) with the latest code updates.
+
+<--->
++++
+title=GitHub repository
++++
+{{% vendor/name %}} provides a [Github integration](integrations/source/github.md) that allows your {{% vendor/name %}} project to be fully integrated with your Github repository.
+This enables you, as a developer, to use a normal Git workflow (`git add . && git commit -m "message" && git push`) to deploy your environment—with no need to connect to the {{% vendor/name %}} Console.
+
+{{< note >}}
+Make sure you complete the following steps before adding a [Github integration](integrations/source/github.md):
+
+1. Create a Git repository in your own organization following the relevant [Github repository creation guide](https://docs.github.com/en/repositories/creating-and-managing-repositories/creating-a-new-repository).
+2. Create a [Github integration](integrations/source/github.md).
+3. Add a Git remote to your local project, from the root of your Express directory.</br>
+   To do so, run the following commands:
+
+    ```bash {location="Terminal"}
+    git remote add origin <urlOfYourOwnGitHubRepo>
+    git add . && git commit -m "init express"
+    git push origin
+    ```
+{{< /note >}}
+
+{{< /codetabs >}}
+
+## 4. Configure your project
+
+To host your Express application on {{% vendor/name %}},
+you need to have a few YAML configuration files at the root of your project.
+These files manage your app's behavior.
+They are located in a `.{{% vendor/cli %}}/` folder at the root of your source code
+and structured in a similar way to this:
+
+```txt
+my-express-app
+├── .{{% vendor/cli %}}
+│   └── config.yaml
+├── [.environment]
+└── <project sources>
+```
+
+To generate these files, run the following command at the root of your project:
+
+``` {location="Terminal"}
+{{% vendor/cli %}} project:init
+```
+
+Follow the prompts.
+
+To commit your new files, run the following commands:
+
+```bash {location="Terminal"}
+git add .
+git commit -m "Add {{% vendor/name %}} config files"
+```
+
+## 5. Deploy
+
+And just like that, it’s time to deploy!
+
+Depending on the Git workflow you chose at the beginning of this tutorial,
+there are two ways to deploy your source code changes.
+
+{{< codetabs >}}
+
++++
+title=Using {{% vendor/name %}} Git repository
++++
+
+You can push your code using the normal Git workflow (`git add . && git commit -m "message" && git push`). This pushes your source code changes to your `{{% vendor/cli %}}` remote repository. Alternatively, you can use the following {{% vendor/name %}} CLI command:
+
+```bash {location="Terminal"}
+{{% vendor/cli %}} push
+```
+
+<--->
++++
+title=Using a third-party Git repository
++++
+
+When you choose to use a third-party Git hosting service, the {{< vendor/name >}} Git
+repository becomes a read-only mirror of the third-party repository. All your
+changes take place in the third-party repository.
+
+Add an integration to your existing third-party repository:
+
+- [BitBucket](/integrations/source/bitbucket.md)
+- [GitHub](/integrations/source/github.md)
+- [GitLab](/integrations/source/gitlab.md)
+
+If you are using an integration, on each code updates,
+use the normal Git workflow (`git add . && git commit -m "message" && git push`) to push your code to your external repository.
+To do so, run the following command:
+
+```bash {location="Terminal"}
+git push origin
+```
+
+Your GitHub, GitLab, or Bibucket integration process then automatically deploys changes to your environment.
+If you're pushing a new Git branch, a new environment is created.
+
+{{< /codetabs >}}
+
+{{% vendor/name %}} then reads your configuration files,
+and deploys your project using [default container resources](/manage-resources/resource-init.md).
+If you don't want to use those default resources,
+define your own [resource initialization strategy](/manage-resources/resource-init.md#define-a-resource-initialization-strategy),
+or [amend those default container resources](/manage-resources/adjust-resources.md) after your project is deployed.
+
+Et voilà, your Express application is live!
+
+{{< note title="Tip" theme="info" >}}
+
+Each environment has its own domain name.
+To open the URL of your new environment, run the following command:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} environment:url --primary
+   ```
+{{< /note >}}
+
+## 6. Make changes to your project
+
+Now that your project is deployed, you can start making changes to it.
+For example, you might want to fix a bug or add a new feature.
+
+In your project, the `main` branch always represents the production environment.
+Other branches are for developing new features, fixing bugs, or updating the infrastructure.
+
+To make changes to your project, follow these steps:
+
+1. Create a new environment (a Git branch) to make changes without impacting production:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} branch feat-a
+   ```
+
+   This command creates a new local `feat-a` Git branch based on the main Git branch,
+   and activates a related environment on {{< vendor/name >}}.
+   The new environment inherits the data (service data and assets) of its parent environment (the production environment here).
+
+2. Make changes to your project.
+   For example, edit the `views/index.jade` file and make the following changes:
+
+   ```diff
+   diff --git a/views/index.jade b/views/index.jade
+   index 3d63b9a..77aee43 100644
+   --- a/views/index.jade
+   +++ b/views/index.jade
+   @@ -2,4 +2,4 @@ extends layout
+ 
+    block content
+      h1= title
+   -  p Welcome to #{title}
+   +  p Welcome to #{title} on Upsun
+   ``
+
+3. Commit your changes:
+
+   ```bash {location="Terminal"}
+   git add views/index.jade
+   git commit -m "Update index page view."
+   ```
+
+4. Deploy your changes to the `feat-a` environment:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} push
+   ```
+
+5. Iterate by changing the code, committing, and deploying.
+   When satisfied with your changes, merge them to the main branch,
+   and remove the feature branch:
+
+   ```bash {location="Terminal"}
+   {{% vendor/cli %}} merge
+       Are you sure you want to merge feat-a into its parent, main? [Y/n] y
+   {{% vendor/cli %}} checkout main
+   git pull {{% vendor/cli %}} main
+   {{% vendor/cli %}} environment:delete feat-a
+   git fetch --prune
+   ```
+   
+   Note that deploying to production is fast because the image built for the `feat-a` environment is reused.
+
+   For a long running branch, to keep the code up-to-date with the main branch, use `git merge main` or `git rebase main`.
+   You can also keep the data in sync with the production environment by using `{{% vendor/cli %}} env:sync`.
+
+## Further resources
+
+### Documentation
+
+- [JavaScript/Node.js documentation](/languages/nodejs/)
+- [Managing dependencies](/languages/nodejs#dependencies)
+- [Add a database to Express](/get-started/stacks/express/add-database)
+
+### Community content
+
+- [ExpressJS topics](https://support.platform.sh/hc/en-us/search?utf8=%E2%9C%93&query=express)
+- [Node.js topics](https://support.platform.sh/hc/en-us/search?utf8=%E2%9C%93&query=node)
+- [JavaScript topics](https://support.platform.sh/hc/en-us/search?utf8=%E2%9C%93&query=js)
+
+### Blogs
+
+- [A quick-start guide on hosting Express on Upsun](https://upsun.com/blog/setting-up-express-on-upsun/)