Try Out Development Containers: Node.js

A development container is a running Docker container with a well-defined tool/runtime stack and its prerequisites. You can try out development containers with GitHub Codespaces or Visual Studio Code Remote - Containers.

This is a sample project that lets you try out either option in a few easy steps. We have a variety of other vscode-remote-try-* sample projects, too.

Note: If you already have a Codespace or dev container, you can jump to the Things to try section.

Setting up the development container

GitHub Codespaces

Follow these steps to open this sample in a Codespace: 1. Click the Code drop-down menu and select the Open with Codespaces option. 1. Select + New codespace at the bottom on the pane.

For more info, check out the GitHub documentation.

VS Code Remote - Containers

Follow these steps to open this sample in a container using the VS Code Remote - Containers extension:

1. If this is your first time using a development container, please ensure your system meets the pre-reqs (i.e. have Docker installed) in the getting started steps.

2. To use this repository, you can either open the repository in an isolated Docker volume:

- Press F1 and select the **Remote-Containers: Try a Sample...** command.
- Choose the "Node" sample, wait for the container to start, and try things out!
    > **Note:** Under the hood, this will use the **Remote-Containers: Clone Repository in Container Volume...** command to clone the source code in a Docker volume instead of the local filesystem. [Volumes](https://docs.docker.com/storage/volumes/) are the preferred mechanism for persisting container data.

Or open a locally cloned copy of the code:

• Clone this repository to your local filesystem.
• Press F1 and select the Remote-Containers: Open Folder in Container... command.
• Select the cloned copy of this folder, wait for the container to start, and try things out!

Things to try

Once you have this sample opened, you'll be able to work with it like you would locally.

Note: This container runs as a non-root user with sudo access by default. Comment out

"remoteUser": "node"

in

.devcontainer/devcontainer.json

if you'd prefer to run as root.

Some things to try:

1. Edit:
   • Open

     server.js

   • Try adding some code and check out the language features.
   • Notice that

     eslint

     and the

     vscode-eslint

     extension are already installed in the container since the

     .devcontainer/devcontainer.json

     lists

     "dbaeumer.vscode-eslint"

     as an extension to install automatically when the container is created.
2. Terminal: Press Ctrl+Shift+` and type

   uname

   and other Linux commands from the terminal window.
3. Build, Run, and Debug:
   • Open

     server.js

   • Add a breakpoint (e.g. on line 20).
   • Press F5 to launch the app in the container.
   • Once the breakpoint is hit, try hovering over variables, examining locals, and more.
   • Continue (F5). You can connect to the server in the container by either:
     • Clicking on

       Open in Browser

       in the notification telling you:

       Your service running on port 3000 is available

       .
     • Clicking the globe icon in the 'Ports' view. The 'Ports' view gives you an organized table of your forwarded ports, and you can access it with the command Ports: Focus on Ports View.
   • Notice port 3000 in the 'Ports' view is labeled "Hello Remote World." In

     devcontainer.json

     , you can set

     "portsAttributes"

     , such as a label for your forwarded ports and the action to be taken when the port is autoforwarded.
     • If we didn't know the port was 3000, we could've used a regex instead of "3000" in the

       "portsAttributes"

       , such as ".+/server.js".

Note: In Remote - Containers, you can access your app at

http://localhost:3000

in a local browser. But in a browser-based Codespace, you must click the link from the notification or the

Ports

view so that the service handles port forwarding in the browser and generates the correct URL.

1. Rebuild or update your container

You may want to make changes to your container, such as installing a different version of a software or forwarding a new port. You'll rebuild your container for your changes to take effect.

Open browser automatically: As an example change, let's update the

portsAttributes

.devcontainer/devcontainer.json

• Open the

  .devcontainer/devcontainer.json

  file.
• Modify the

  "onAutoForward"

  attribute in your

  portsAttributes

  from

  "notify"

  to

  "openBrowser"

  .
• Press F1 and select the Remote-Containers: Rebuild Container or Codespaces: Rebuild Container command so the modifications are picked up.

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

License

Copyright © Microsoft Corporation All rights reserved.
Licensed under the MIT License. See LICENSE in the project root for license information.