Follow this guide to get started with creating a basic Docker extension. The Quickstart guide automatically generates boilerplate files for you.
NodeJS and Go are only required when you follow the quickstart guide to create an extension. It uses the
docker extension initcommand to automatically generate boilerplate files. This command uses a template based on a ReactJS and Go application.
To set up your directory, use the
init subcommand and provide a name for your extension.
$ docker extension init <my-extension>
The command asks a series of questions about your extension, such as its name, a description, and the name of your Hub repository. This helps the CLI generate a set of boilerplate files for you to get started. It stores the boilerplate files in the
The automatically generated extension contains:
- A Go backend service in the
backendfolder that listens on a socket. It has one endpoint
/hellothat returns a JSON payload.
- A React frontend in the
frontendfolder that can call the backend and output the backend’s response.
For more information and guidelines on building the UI, see the Design and UI styling section.
To build the extension, move into the newly created directory and run:
$ docker build -t <name-of-your-extension> .
docker build builds the extension and generates an image named the same as the chosen hub repository. For example, if you typed
john/my-extension as the answer to the following question:
? Hub repository (eg. namespace/repository on hub): john/my-extension`
docker build generates an image with name
To install the extension in Docker Desktop, run:
$ docker extension install <name-of-your-extension>
To preview the extension in Docker Desktop, once the installation is complete and you should see a Quickstart item underneath the Extensions menu. Selecting this item opens the extension's frontend.
During UI development, it’s helpful to use hot reloading to test your changes without rebuilding your entire extension. See Preview whilst developing the UI for more information.
You may also want to inspect the containers that belong to the extension. By default, extension containers are hidden from the Docker Dashboard. You can change this in Settings, see how to show extension containers for more information.
If you want to make your extension available to all Docker Desktop users, you can submit it for publication in the Marketplace. For more information, see Publish.
To remove the extension, run:
$ docker extension rm <name-of-your-extension>
Already built an extension?
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