ci: also publish release images to Docker Hub

.github/workflows/publish-ghcr-image.yml

@@ -1,4 +1,4 @@
-name: Build & Publish GHCR Image
+name: Build & Publish Release Image
 
 on:
   push:
@@ -17,7 +17,10 @@ concurrency:
 
 env:
   versionTag: ${{ inputs.version || github.ref_name }}
-  registry: ghcr.io
+  ghcrRegistry: ghcr.io
+  dockerHubRegistry: docker.io
+  imageName: ${{ github.repository }}
+  dockerHubImage: vechain/block-explorer
 
 jobs:
   build:
@@ -50,7 +53,7 @@ jobs:
       - name: Login to GHCR
         uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
         with:
-          registry: ${{ env.registry }}
+          registry: ${{ env.ghcrRegistry }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
@@ -67,7 +70,7 @@ jobs:
           sbom: false
           cache-from: type=gha,scope=buildkit-${{ matrix.arch }}
           cache-to: type=gha,mode=max,scope=buildkit-${{ matrix.arch }}
-          outputs: type=image,name=${{ env.registry }}/${{ github.repository }},push-by-digest=true,name-canonical=true,push=true
+          outputs: type=image,name=${{ env.ghcrRegistry }}/${{ env.imageName }},push-by-digest=true,name-canonical=true,push=true
 
       - name: Export digest
         run: |
@@ -104,10 +107,17 @@ jobs:
       - name: Login to GHCR
         uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
         with:
-          registry: ${{ env.registry }}
+          registry: ${{ env.ghcrRegistry }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
+      - name: Login to Docker Hub
+        uses: docker/login-action@c94ce9fb468520275223c153574b00df6fe4bcc9 # v3
+        with:
+          registry: ${{ env.dockerHubRegistry }}
+          username: ${{ vars.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
       - name: Extract version tags
         id: version
         run: |
@@ -124,24 +134,50 @@ jobs:
             echo "stable=false" >> "$GITHUB_OUTPUT"
           fi
 
-      - name: Create manifest list and push
+      - name: Create GHCR manifest list
         working-directory: /tmp/digests
         env:
-          IMAGE: ${{ env.registry }}/${{ github.repository }}
+          GHCR_IMAGE: ${{ env.ghcrRegistry }}/${{ env.imageName }}
+          FULL_VERSION: ${{ steps.version.outputs.full }}
+          STABLE: ${{ steps.version.outputs.stable }}
+          MAJOR: ${{ steps.version.outputs.major }}
+          MINOR: ${{ steps.version.outputs.minor }}
         run: |
-          TAGS="-t ${{ env.IMAGE }}:${{ steps.version.outputs.full }}"
+          set -euo pipefail
 
-          if [ "${{ steps.version.outputs.stable }}" = "true" ]; then
-            TAGS="$TAGS -t ${{ env.IMAGE }}:${{ steps.version.outputs.minor }}"
-            TAGS="$TAGS -t ${{ env.IMAGE }}:${{ steps.version.outputs.major }}"
-            TAGS="$TAGS -t ${{ env.IMAGE }}:latest"
+          tags=("-t" "${GHCR_IMAGE}:${FULL_VERSION}")
+          if [ "${STABLE}" = "true" ]; then
+            tags+=("-t" "${GHCR_IMAGE}:${MINOR}")
+            tags+=("-t" "${GHCR_IMAGE}:${MAJOR}")
+            tags+=("-t" "${GHCR_IMAGE}:latest")
           fi
 
-          IMAGE_REFS=()
+          refs=()
           for digest in *; do
-            IMAGE_REFS+=("${IMAGE}@sha256:${digest}")
+            refs+=("${GHCR_IMAGE}@sha256:${digest}")
           done
 
-          docker buildx imagetools create \
-            $TAGS \
-            "${IMAGE_REFS[@]}"
+          docker buildx imagetools create "${tags[@]}" "${refs[@]}"
+
+      - name: Mirror manifest from GHCR to Docker Hub
+        env:
+          GHCR_IMAGE: ${{ env.ghcrRegistry }}/${{ env.imageName }}
+          DOCKERHUB_IMAGE: ${{ env.dockerHubRegistry }}/${{ env.dockerHubImage }}
+          FULL_VERSION: ${{ steps.version.outputs.full }}
+          STABLE: ${{ steps.version.outputs.stable }}
+          MAJOR: ${{ steps.version.outputs.major }}
+          MINOR: ${{ steps.version.outputs.minor }}
+        run: |
+          set -euo pipefail
+
+          copy_tag() {
+            local tag="$1"
+            docker buildx imagetools create -t "${DOCKERHUB_IMAGE}:${tag}" "${GHCR_IMAGE}:${tag}"
+          }
+
+          copy_tag "${FULL_VERSION}"
+          if [ "${STABLE}" = "true" ]; then
+            copy_tag "${MINOR}"
+            copy_tag "${MAJOR}"
+            copy_tag "latest"
+          fi