Set up CI for plugins

This will lint, test, and publish individual plugins.

.github/workflows/publish.yaml

@@ -0,0 +1,28 @@
+name: Publish
+
+# This workflow will publish releases published on GitHub to NPM.
+
+on:
+  release:
+    types:
+      - released
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: The tag to publish (for example "coder/v0.0.0")
+        type: string
+        required: true
+
+concurrency: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+  npm:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: robinraju/release-downloader@v1.9
+        with:
+          tag: ${{ github.event.inputs.tag || github.ref_name }}
+          fileName: "*.tgz"
+      - run: yarn publish *.tgz
+        env:
+          NPM_TOKEN: ${{ secrets.NPM_TOKEN }}

.github/workflows/release.yaml

@@ -0,0 +1,54 @@
+name: Release
+
+# This workflow will draft a release for a plugin when tagged.
+# The tag format is <name>/v<version> without the backstage-plugin- prefix.
+
+on:
+  push:
+    tags:
+      - "*/v*"
+
+permissions:
+  contents: write # For creating releases.
+
+concurrency: ${{ github.workflow }}-${{ github.ref }}
+
+jobs:
+  split-tag:
+    runs-on: ubuntu-latest
+    outputs:
+      plugin: ${{ steps.split.outputs.plugin }}
+      version: ${{ steps.split.outputs.version }}
+    steps:
+      - env:
+          TAG: ${{ github.ref_name }}
+        id: split
+        run: |
+          parts=(${TAG//\/v/ })
+          echo "plugin=${parts[0]}" >> $GITHUB_OUTPUT
+          echo "version=${parts[1]}" >> $GITHUB_OUTPUT
+  plugin:
+    needs: split-tag
+    runs-on: ubuntu-latest
+    defaults:
+      run:
+        working-directory: plugins/backstage-plugin-${{ needs.split-tag.outputs.plugin }}
+    name: ${{ needs.split-tag.outputs.plugin }} v${{ needs.split-tag.outputs.version }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+          cache: yarn
+      - run: yarn install --frozen-lockfile
+      - run: yarn lint
+      - run: yarn tsc
+      - run: yarn test
+      - run: yarn build
+      # Version it with the version in the tag and upload it to a draft release.
+      - run: yarn version --new-version ${{ needs.split-tag.outputs.version }}
+      - run: yarn pack
+      - uses: softprops/action-gh-release@v1
+        with:
+          draft: true
+          files: plugins/backstage-plugin-${{ needs.split-tag.outputs.plugin }}/*.tgz

.github/workflows/test.yaml

@@ -0,0 +1,63 @@
+name: Test
+
+# This workflow will lint and test a plugin whenever it or CI changes.
+
+on:
+  push:
+    branches:
+      - main
+  pull_request:
+    branches:
+      - main
+
+# Cancel in-progress runs for pull requests when developers push changes.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ github.ref != 'refs/heads/main' }}
+
+jobs:
+  changes:
+    runs-on: ubuntu-latest
+    outputs:
+      plugins: ${{ steps.filter.outputs.changes }}
+    steps:
+      # Pull requests do not need to check out the code to detect changes
+      # because the action fetches changed files through the API.
+      - uses: actions/checkout@v4
+        if: github.event_name != 'pull_request'
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            coder:
+              - ".github/workflows/build.yaml"
+              - "plugins/backstage-plugin-coder/**"
+  plugin:
+    needs: changes
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        plugin: ${{ fromJSON(needs.changes.outputs.plugins) }}
+    name: ${{ matrix.plugin }}
+    defaults:
+      run:
+        working-directory: plugins/backstage-plugin-${{ matrix.plugin }}
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
+        with:
+          node-version-file: .node-version
+          cache: yarn
+      - run: yarn install --frozen-lockfile
+      - run: yarn lint
+      - run: yarn tsc
+      - run: yarn test
+      - run: yarn build
+      # Version it with the SHA and upload to the run as an artifact in case
+      # someone needs to download it for testing.
+      - run: yarn version --new-version "0.0.0-devel+$GITHUB_SHA"
+      - run: yarn pack
+      - uses: actions/upload-artifact@v4
+        with:
+          name: ${{ matrix.plugin }}
+          path: plugins/backstage-plugin-${{ matrix.plugin }}/*.tgz

.node-version

@@ -0,0 +1 @@
+18.19.0

.yarnrc

@@ -0,0 +1,4 @@
+# We add the tags ourselves and do not commit the version bump; prevent Yarn
+# from trying to do so.
+version-git-tag false
+version-commit-hooks false

README.md

@@ -1,10 +1,32 @@
 # [Backstage](https://backstage.io)
 
-This is your newly scaffolded Backstage App, Good Luck!
+## Contributing
 
-To start the app, run:
+To start the app:
 
 ```sh
 yarn install
 yarn dev
 ```
+
+To run an individual plugin:
+
+```sh
+cd plugins/backstage-plugin-$name
+yarn install
+yarn start
+```
+
+## Releasing
+
+To draft a release for a plugin push a tag named `$name/v$version` without the
+`backstage-plugin-` prefix.  For example:
+
+```sh
+git tag -a coder/v0.0.0 -m "coder v0.0.0"
+git push origin coder/v0.0.0
+```
+
+This will kick off an action that will create a draft release for the plugin.
+Once you have reviewed the release you can publish it and another action will
+publish the plugin to NPM.

packages/app/package.json

@@ -39,7 +39,7 @@
     "@backstage/plugin-techdocs-react": "^1.1.15",
     "@backstage/plugin-user-settings": "^0.8.0",
     "@backstage/theme": "^0.5.0",
-    "@coder/backstage-plugin-coder": "^0.1.0",
+    "@coder/backstage-plugin-coder": "^0.0.0",
     "@material-ui/core": "^4.12.2",
     "@material-ui/icons": "^4.9.1",
     "history": "^5.0.0",

plugins/backstage-plugin-coder/package.json

@@ -1,6 +1,6 @@
 {
   "name": "@coder/backstage-plugin-coder",
-  "version": "0.1.0",
+  "version": "0.0.0",
   "main": "src/index.ts",
   "types": "src/index.ts",
   "license": "Apache-2.0",

yarn.lock

@@ -9571,7 +9571,7 @@ anymatch@^3.0.3, anymatch@~3.1.2:
     "@backstage/plugin-techdocs-react" "^1.1.15"
     "@backstage/plugin-user-settings" "^0.8.0"
     "@backstage/theme" "^0.5.0"
-    "@coder/backstage-plugin-coder" "^0.1.0"
+    "@coder/backstage-plugin-coder" "^0.0.0"
     "@material-ui/core" "^4.12.2"
     "@material-ui/icons" "^4.9.1"
     history "^5.0.0"