feat: add pull-docker-image action

README.md

@@ -349,6 +349,36 @@ jobs using a registry.
 - run: docker run ${{ steps.docker.outputs.tagged-image }}
 ```
 
+#### pull-docker-image
+
+[Source](pull-docker-image/action.yml)
+
+Pulls and caches a docker image. Outputs the image name that was input to provide an easy way to not have to repeat the image name in the rest of your workflow.
+
+##### Inputs
+
+| Required | Name              | Description                 | Example            | Default          |
+|----------|-------------------|-----------------------------|--------------------|------------------|
+| Yes      | `image`           | Image name                  | `my-name/my-image` | –                |
+| No       | `cache-directory` | Directory to store cache in | `/path/to/cache`   | `/.docker-cache` |
+
+##### Outputs
+
+| Name    | Description | Example            |
+|---------|-------------|--------------------|
+| `image` | Image name  | `my-name/my-image` |
+
+##### Example
+
+```yaml
+- uses: myparcelnl/actions/pull-docker-image@v3
+  id: pull
+  with:
+    image: ghcr.io/myparcelnl/php-xd:7.4
+
+- run: docker run ${{ steps.pull.outputs.image }}
+```
+
 ### Releasing
 
 #### semantic-release
@@ -421,7 +451,6 @@ Set up git credentials and authenticate as a [GitHub app].
 | `git-name`  | The name to use with git.    | `my-app[bot]`                          |
 | `git-email` | The email to use with git.   | `my-app[bot]@users.noreply.github.com` |
 
-
 #### rebase
 
 [Source](rebase/action.yml)

pull-docker-image/action.yml

@@ -0,0 +1,40 @@
+name: 'Pull Docker image'
+description: 'Pull Docker image from registry, or load it from cache.'
+
+inputs:
+  image:
+    description: 'Image name'
+    required: true
+
+  cache-directory:
+    description: 'Directory to store cache in'
+    required: false
+    default: '/.docker-cache'
+
+outputs:
+  image:
+    description: 'Image name'
+    value: ${{ inputs.image }}
+
+runs:
+  using: composite
+  steps:
+    - uses: actions/cache@v3
+      id: docker-cache
+      with:
+        path: ${{ inputs.cache-directory }}
+        key: docker-cache-${{ runner.os }}
+
+    - name: 'Load cached Docker image'
+      if: steps.docker-cache.outputs.cache-hit == 'true'
+      shell: bash
+      run: |
+        docker load -i ${{ inputs.cache-directory }}/image.tar
+
+    - name: 'Pull Docker image'
+      if: steps.docker-cache.outputs.cache-hit != 'true'
+      shell: bash
+      run: |
+        docker pull ${{ inputs.image }}
+        mkdir -p ${{ inputs.cache-directory }}
+        docker save -o ${{ inputs.cache-directory }}/image.tar ${{ inputs.image }} }}