Building and Shipping Plugins

This section explains how to start developing a Headlamp plugin, and how to ship it once finished.

Creating a new plugin

This is how to start a new plugin:

npx --yes @kinvolk/headlamp-plugin create headlamp-myfancy
cd headlamp-myfancy
npm run start

There’s some basic code inside src/index.tsx.

Now run Headlamp (the desktop app or the development version ), and your plugin should be loaded.

Using the above commands means that Headlamp will automatically reload whenever to make a change to the plugin.

ℹ️ This automatic reload does not happen when running in-cluster, even if the plugins folder is changed. i.e. if you want to serve updated plugins, you need to restart the server.

Code Formatting, Linting, and Type Checking

Your plugin has a few tools built in to help make development easier.

Format code with prettier

npm run format

Find code lint issues with eslint

npm run lint

Eslint also allows you to try and automatically fix issues.

npm run lint-fix

Run the type checker

npm run tsc

Building for production

To build the previous plugin example for production, run the following command:

cd headlamp-myfancy
npm run build

This will create a file with the bundled plugin in headlamp-myfancy/dist/main.js.

Building a folder of packages at once

For convienience the headlamp-plugin build command can build a package or folder of packages.

npx @kinvolk/headlamp-plugin build myplugins/headlamp-myfancy
npx @kinvolk/headlamp-plugin build myplugins

Shipping and Deploying Plugins

Once a plugin is ready to be shipped (built for production) it needs to be placed in a “plugins directory”, for Headlamp to load them.

For example, if we have built 3 plugins called MyPlugin1, MyPlugin2, and MyPlugin3, they should be added to a directory in the following structure:

.plugins/
  MyPlugin1/
    main.js
  MyPlugin2/
    main.js
  MyPlugin3/
    main.js

If our plugins are places in myplugins, we can conveniently create that folder with the following command:

npx @kinvolk/headlamp-plugin extract ./myplugins /path/to/.plugins

This also works individually (for each plugin):

npx @kinvolk/headlamp-plugin extract ./myplugins/MyPlugin1 /path/to/./plugins

In-cluster deployment with plugins

For in-cluster Headlamp deployments, when running Headlamp’s server, the -plugin-dir option should point to the directory:

./headlamp-server -plugins-dir=.plugins

Using plugins on the desktop version

The Headlamp desktop app will look for the plugins directory (in the format mentioned above) either under the user’s Headlamp configuration folder, or within the current folder as .plugins if the former doesn’t exist.

Bundling plugins with desktop version

To build a Headlamp app with a set of plugins, first extract some plugins into the .plugins folder in the root of the “headlamp” repo.

cd plugins/examples/pod-counter
npm install
npm run build
cd ../..

mkdir .plugins
npx @kinvolk/headlamp-plugin extract ./plugins/examples/ ./.plugins
ls -la .plugins
make app-linux

For more on how to extract files into there see “Shipping and Deploying Plugins” above.