feature(bake): add promote action

Author: jobcespedes

buildx-bake/promote/action.yml

@@ -0,0 +1,93 @@
+name: "Promote Manifests"
+description: "Promote an existing manifest with new tags"
+inputs:
+  version:
+    description: 'Conventional version to promote (e.g. 1.2.3)'
+    required: true
+  image-digests:
+    description: 'JSON with all merged image manifest digests'
+    required: true
+  registry:
+    description: 'The container registry'
+    required: false
+    default: 'ghcr.io'
+  registry-username:
+    description: 'The container registry username'
+    required: true
+    default: ${{ github.actor }}
+  registry-password:
+    description: 'The container registry password'
+    required: true
+  tag-latest:
+    description: 'Also tag as latest'
+    required: false
+    default: 'true'
+  tag-major:
+    description: 'Also tag with major version'
+    required: false
+    default: 'true'
+  tag-minor:
+    description: 'Also tag with major.minor version'
+    required: false
+    default: 'true'
+runs:
+  using: "composite"
+  steps:
+    - name: Login to registry
+      uses: docker/login-action@v3
+      with:
+        registry: ${{ inputs.registry }}
+        username: ${{ inputs.registry-username }}
+        password: ${{ inputs.registry-password }}
+
+    - name: Setup Docker Buildx
+      uses: docker/setup-buildx-action@v3
+
+    - name: Promote manifests
+      shell: python
+      env:
+        VERSION: ${{ inputs.version }}
+        IMAGE_DIGESTS: ${{ inputs.image-digests }}
+        TAG_LATEST: ${{ inputs.tag-latest }}
+        TAG_MAJOR: ${{ inputs.tag-major }}
+        TAG_MINOR: ${{ inputs.tag-minor }}
+      run: |
+        import json, os, re, subprocess
+
+        version = os.environ["VERSION"]
+        image_digests = json.loads(os.environ["IMAGE_DIGESTS"])
+        tag_latest = os.environ["TAG_LATEST"].lower() == "true"
+        tag_major = os.environ["TAG_MAJOR"].lower() == "true"
+        tag_minor = os.environ["TAG_MINOR"].lower() == "true"
+
+        # Parse semantic version
+        m = re.match(r"^v?(\d+)\.(\d+)\.(\d+)", version)
+        if not m:
+            raise ValueError(f"Invalid semantic version: {version}")
+        major, minor, patch = m.groups()
+        version_clean = f"{major}.{minor}.{patch}"
+
+        # Build tag list
+        tags = [version_clean]
+        if tag_minor:
+            tags.append(f"{major}.{minor}")
+        if tag_major:
+            tags.append(major)
+        if tag_latest:
+            tags.append("latest")
+
+        print(f"Promoting version: {version_clean}", flush=True)
+        print(f"Tags: {', '.join(tags)}", flush=True)
+
+        def run(cmd):
+            print(f"+ {' '.join(cmd)}", flush=True)
+            subprocess.run(cmd, check=True)
+
+        # Promote each image
+        for item in image_digests:
+            image_name = item["name"]
+            digest = item["digest"]
+            source = f"{image_name}@{digest}"
+            tag_args = [a for t in tags for a in ("-t", f"{image_name}:{t}")]
+            print(f"\nPromoting: {source}", flush=True)
+            run(["docker", "buildx", "imagetools", "create", *tag_args, source])