Test supports remote

actions/docker-build-push/action.yml

@@ -33,12 +33,42 @@ inputs:
   github_token:
     description: 'GitHub token for metadata extraction'
     required: true
+  repository_checkout:
+    description: 'Repository to checkout (if different from the current one)'
+    required: false
+    default: ''
+  ref_checkout:
+    description: 'Git ref (branch/tag/SHA) to checkout in the external repo'
+    required: false
+    default: ''
 
 runs:
   using: "composite"
   steps:
-    - name: Checkout repository
+    - name: Checkout external repository
+      if: ${{ inputs.repository_checkout != '' }}
       uses: actions/checkout@v5
+      with:
+        repository: ${{ inputs.repository_checkout }}
+        ref: ${{ inputs.ref_checkout != '' && inputs.ref_checkout || 'main' }}
+        server-url: ${{ github.server_url }}
+        path: external-src
+        fetch-depth: 0
+
+    - name: Checkout repository
+      if: ${{ inputs.repository_checkout == '' }}
+      uses: actions/checkout@v5
+      with:
+        fetch-depth: 0
+
+    - name: Set build context path if remote specified else local
+      id: set-context
+      run: |
+        if [ "${{ inputs.repository_checkout }}" != "" ]; then
+          echo "context_path=external-src" >> $GITHUB_OUTPUT
+        else
+          echo "context_path=${{ inputs.context_path }}" >> $GITHUB_OUTPUT
+        fi
 
     - name: Define branch helpers
       id: branch
@@ -79,7 +109,7 @@ runs:
     - name: Build and push Docker image
       uses: docker/build-push-action@v5
       with:
-        context: ${{ inputs.context_path }}
+        context: ${{ steps.set-context.outputs.context_path }}
         file: ${{ inputs.dockerfile_path }}
         push: true
         platforms: ${{ inputs.platforms }}