Enhance GitHub Actions workflow by adding environment variables for GHCR repository and improving image tag preparation logic. Update DockerHub sync step to conditionally use password or token. Refactor output handling for built images.

.github/workflows/main.yml

@@ -5,6 +5,9 @@ on:
     branches:
       - 'master'
 
+env:
+  GHCR_REPOSITORY: ghcr.io/${{ github.repository }}
+
 jobs:
   quality-checks:
     runs-on: ubuntu-latest
@@ -64,9 +67,28 @@ jobs:
       -
         name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v4
+      -
+        name: Prepare image tags
+        id: image_tags
+        env:
+          DOCKERHUB_REPOSITORY: ${{ secrets.DOCKERHUB_REPOSITORY }}
+          GHCR_REPOSITORY: ${{ env.GHCR_REPOSITORY }}
+          DATE: ${{ steps.date.outputs.date }}
+        run: |
+          {
+            echo 'tags<<EOF'
+            if [ -n "$DOCKERHUB_REPOSITORY" ]; then
+              echo "${DOCKERHUB_REPOSITORY}:latest"
+              echo "${DOCKERHUB_REPOSITORY}:${DATE}"
+            fi
+            echo "${GHCR_REPOSITORY}:latest"
+            echo "${GHCR_REPOSITORY}:${DATE}"
+            echo EOF
+          } >> "$GITHUB_OUTPUT"
       -
         name: Login to DockerHub
         uses: docker/login-action@v4
+        if: ${{ secrets.DOCKERHUB_USERNAME != '' && secrets.DOCKERHUB_TOKEN != '' }}
         with:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
@@ -86,21 +108,18 @@ jobs:
           push: true
           build-args: |
             VERSION=${{ steps.date.outputs.date }}
-          tags: |
+          tags: ${{ steps.image_tags.outputs.tags }}
-            ${{ secrets.DOCKERHUB_REPOSITORY }}:latest
-            ${{ secrets.DOCKERHUB_REPOSITORY }}:${{ steps.date.outputs.date }}
-            ghcr.io/${{ github.repository }}:latest
-            ghcr.io/${{ github.repository }}:${{ steps.date.outputs.date }}
 
   dockerhub-sync-readme:
     needs: dockerhub-build-push
     runs-on: ubuntu-latest
+    if: ${{ secrets.DOCKERHUB_USERNAME != '' && (secrets.DOCKERHUB_PASSWORD != '' || secrets.DOCKERHUB_TOKEN != '') && secrets.DOCKERHUB_REPOSITORY != '' }}
     steps:
       - name: Sync README
         uses: docker://lsiodev/readme-sync:latest
         env:
           DOCKERHUB_USERNAME: ${{ secrets.DOCKERHUB_USERNAME }}
-          DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD }}
+          DOCKERHUB_PASSWORD: ${{ secrets.DOCKERHUB_PASSWORD != '' && secrets.DOCKERHUB_PASSWORD || secrets.DOCKERHUB_TOKEN }}
           GIT_REPOSITORY: ${{ github.repository }}
           DOCKER_REPOSITORY: ${{ secrets.DOCKERHUB_REPOSITORY }}
           GIT_BRANCH: master
@@ -157,7 +176,7 @@ jobs:
         id: release_body
         env:
           DOCKERHUB_REPO: ${{ secrets.DOCKERHUB_REPOSITORY }}
-          GHCR_REPO: ghcr.io/${{ github.repository }}
+          GHCR_REPO: ${{ env.GHCR_REPOSITORY }}
           DATE: ${{ steps.date.outputs.date }}
           HAS_COMMITS: ${{ steps.commits.outputs.has_commits }}
           COMMITS: ${{ steps.commits.outputs.commits }}
@@ -167,10 +186,12 @@ jobs:
             echo ''
             echo 'Docker images have been built and pushed:'
             echo ''
+            if [ -n "$DOCKERHUB_REPO" ]; then
               echo '**Docker Hub:**'
               echo "- \`${DOCKERHUB_REPO}:latest\`"
               echo "- \`${DOCKERHUB_REPO}:${DATE}\`"
               echo ''
+            fi
             echo '**GitHub Container Registry:**'
             echo "- \`${GHCR_REPO}:latest\`"
             echo "- \`${GHCR_REPO}:${DATE}\`"