ci: only publish on tagged releases

.github/workflows/deploy-image.yaml

@@ -3,7 +3,6 @@ name: Create and publish a Docker image
 # Publish semver tags as releases.
 on:
   push:
-    branches: ['main']
     tags: [ 'v*.*.*' ]
 
 # Defines two custom environment variables for the workflow. These are used for the Container registry domain, and a name for the Docker image that this workflow builds.
@@ -21,7 +20,7 @@ jobs:
       packages: write
       attestations: write
       id-token: write
-       
+
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
@@ -33,14 +32,14 @@ jobs:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
-          
+
       # This step uses [docker/metadata-action](https://github.com/docker/metadata-action#about) to extract tags and labels that will be applied to the specified image. The `id` "meta" allows the output of this step to be referenced in a subsequent step. The `images` value provides the base name for the tags and labels.
       - name: Extract metadata (tags, labels) for Docker
         id: meta
         uses: docker/metadata-action@9ec57ed1fcdbf14dcef7dfbe97b2010124a938b7
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
-          
+
       # This step uses the `docker/build-push-action` action to build the image, based on your repository's `Dockerfile`. If the build succeeds, it pushes the image to GitHub Packages.
       # It uses the `context` parameter to define the build's context as the set of files located in the specified path. For more information, see "[Usage](https://github.com/docker/build-push-action#usage)" in the README of the `docker/build-push-action` repository.
       # It uses the `tags` and `labels` parameters to tag and label the image with the output from the "meta" step.
@@ -52,12 +51,11 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
-      
-      # This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see "[AUTOTITLE](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds)." 
+
+      # This step generates an artifact attestation for the image, which is an unforgeable statement about where and how it was built. It increases supply chain security for people who consume the image. For more information, see "[AUTOTITLE](/actions/security-guides/using-artifact-attestations-to-establish-provenance-for-builds)."
       - name: Generate artifact attestation
         uses: actions/attest-build-provenance@v1
         with:
           subject-name: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
           subject-digest: ${{ steps.push.outputs.digest }}
           push-to-registry: true
-