ci: Package action automatically on release branch (#15)

.github/workflows/build_action.yaml

@@ -0,0 +1,19 @@
+name: "Build Action (if not available)"
+
+on: [workflow_call]
+
+jobs:
+  build-action:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: npm install
+      - name: Build action (if not already built)
+        if: "!startsWith(github.ref, 'refs/heads/release')"
+        run: npm run build
+      - name: Push build into cache
+        if: "!startsWith(github.ref, 'refs/heads/release')"
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}

.github/workflows/directory.yml

@@ -3,11 +3,20 @@ name: Test Directory Extraction
 on: [push]
 
 jobs:
+  action:
+    uses: ./.github/workflows/build_action.yaml
   root-directory:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Contents of Directory from Example Image
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract
@@ -22,9 +31,16 @@ jobs:
       - run: test -e ${{ steps.extract.outputs.destination }}/y/006.txt || exit 1
   nested-directory:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Nested Directory from Example Image
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract
@@ -35,9 +51,16 @@ jobs:
       - run: test -e ${{ steps.extract.outputs.destination }}/x/005.txt || exit 1
   nested-directory-contents:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Nested Contents of Directory from Example Image
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract

.github/workflows/file.yml

@@ -3,11 +3,20 @@ name: Test File Extraction
 on: [push]
 
 jobs:
+  action:
+    uses: ./.github/workflows/build_action.yaml
   root-file:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Example File From Root of Built Image
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract
@@ -17,9 +26,16 @@ jobs:
       - run: test -e ${{ steps.extract.outputs.destination }}/001.txt || exit 1
   nested-file:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Nexted Example File From Built Image
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract

.github/workflows/package-action.yaml

@@ -0,0 +1,35 @@
+name: "Package Action"
+
+on:
+  push:
+    branches:
+      - "main"
+
+env:
+  source: "main"
+  release: "release"
+
+jobs:
+  package-changes:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ref: "${{ env.release }}"
+          fetch-depth: 0
+          ssh-key: "${{ secrets.COMMIT_KEY }}"
+      - uses: pr-mpt/actions-merge-branch@v2
+        with:
+          from: "origin/${{ env.source }}"
+          commit: false
+      - name: Install Javascript dependencies with npm
+        run: npm install
+      - name: Package action for distribution
+        run: npm run package
+      - name: Push packaged action to branch
+        uses: EndBug/add-and-commit@v7
+        with:
+          add: "['.', 'dist --force']"
+          branch: "${{ env.release }}"
+          default_author: github_actions
+          message: "build: Package action as `dist` with latest changes"

.github/workflows/platforms.yml

@@ -3,11 +3,20 @@ name: Test Cross Platform Support
 on: [push]
 
 jobs:
+  action:
+    uses: ./.github/workflows/build_action.yaml
   linux:
     runs-on: ubuntu-latest
+    needs:
+      - action
     name: Extract Example File on Ubuntu
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - run: docker build -t example:${{ github.sha }} ./.github/tests
       - uses: ./
         id: extract
@@ -17,9 +26,16 @@ jobs:
       - run: test -e ${{ steps.extract.outputs.destination }}/001.txt || exit 1
   macos:
     runs-on: macos-latest
+    needs:
+      - action
     name: Extract Example File on macOS
     steps:
       - uses: actions/checkout@v2
+      - name: Load action build from cache
+        uses: actions/cache@v3
+        with:
+          path: dist
+          key: build-${{ github.sha }}
       - name: Install Docker
         env:
           HOMEBREW_GITHUB_API_TOKEN: "${{ github.token }}"

.github/workflows/validate-tag.yaml

@@ -0,0 +1,22 @@
+name: "Limit Tags To Distributable Commits"
+
+on:
+  push:
+    tags:
+      - "**"
+
+jobs:
+  validate-tag:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ssh-key: "${{ secrets.COMMIT_KEY }}"
+      - name: Test that the tagged commit includes `dist`
+        uses: pr-mpt/actions-assert@v2
+        with:
+          assertion: npm://@assertions/directory-exists
+          expected: dist
+      - if: failure()
+        name: Delete invalid tag
+        uses: pr-mpt/actions-delete-tag@v1

.gitignore

@@ -1 +1,2 @@
 node_modules/
+/dist/

README.md

@@ -5,27 +5,27 @@ A GitHub Action for extracting files from a Docker Image.
 ```yaml
 - uses: shrink/actions-docker-extract@v1
   with:
-    image: 'ghost:alpine'
-    path: '/var/lib/ghost/current/core/built/assets/.'
+    image: "ghost:alpine"
+    path: "/var/lib/ghost/current/core/built/assets/."
 ```
 
 ## Inputs
 
 All inputs are required.
 
-| ID  | Description | Examples |
-| --- | ----------- | -------- |
-| `image` | Docker Image to extract files from | `alpine` `ghcr.io/github/super-linter:latest` |
-| `path` | Path (from root) to a file or directory within Image | `files/example.txt` `files` `files/.` |
+| ID      | Description                                          | Examples                                      |
+| ------- | ---------------------------------------------------- | --------------------------------------------- |
+| `image` | Docker Image to extract files from                   | `alpine` `ghcr.io/github/super-linter:latest` |
+| `path`  | Path (from root) to a file or directory within Image | `files/example.txt` `files` `files/.`         |
 
 > :paperclip: To copy the **contents** of a directory the `path` must end with
-`/.` otherwise the directory itself will be copied. More information about the
-specific rules can be found via the [docker cp][docker-cp] documentation.
+> `/.` otherwise the directory itself will be copied. More information about the
+> specific rules can be found via the [docker cp][docker-cp] documentation.
 
 ## Outputs
 
-| ID  | Description | Example |
-| --- | ----------- | ------- |
+| ID            | Description                                       | Example                  |
+| ------------- | ------------------------------------------------- | ------------------------ |
 | `destination` | Destination path containing the extracted file(s) | `.extracted-1598717412/` |
 
 ## Examples
@@ -88,6 +88,25 @@ jobs:
           name: dist
 ```
 
+## Automatic Release Packaging
+
+A Workflow packages the Action automatically when a collaborator created a new
+tag. Any reference to this Action in a Workflow must use a [tag][tags] (mutable)
+or the commit hash of a tag (immutable).
+
+```yaml
+✅ uses: shrink/actions-docker-extract@v2
+✅ uses: shrink/actions-docker-extract@v2.0.0
+✅ uses: shrink/actions-docker-extract@abde1147dd0d248b38feda9e75768c3d2b57eefc
+❌ uses: shrink/actions-docker-extract@main
+```
+
+The blog post
+[Package GitHub Actions automatically with GitHub Actions][blog/package-automatically]
+describes how this is achieved.
+
 [build-push-action]: https://github.com/docker/build-push-action
 [login-action]: https://github.com/docker/login-action
 [docker-cp]: https://docs.docker.com/engine/reference/commandline/cp/#extended-description
+[tags]: https://github.com/shrink/actions-docker-extract/tags
+[blog/package-automatically]: https://medium.com/prompt/package-github-actions-automatically-with-github-actions-a70b9f7bae4