feat: add publish image workflow

.github/workflows/publish-image.yml

@@ -0,0 +1,60 @@
+name: Publish Image
+
+on: 
+  release:
+    types: [published]
+
+# Ensure only the most recent workflow runs.
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  publish_to_ghcr:
+    name: Publish image to ghcr.io
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out
+        uses: actions/checkout@v2
+
+      - name: Lowercase repo owner
+        id: lowercase_repo_owner
+        uses: ASzc/change-string-case-action@v1
+        with:
+          string: ${{ github.repository_owner }}
+
+      - name: Setup Image Metadata
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            ghcr.io/${{ steps.lowercase_repo_owner.outputs.lowercase }}/aries-acapy-plugin-toolbox
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha
+
+      - name: Log in to the GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Build and Push to Docker ghcr.io
+        uses: docker/build-push-action@v2
+        with:
+          push: true
+          file: docker/Dockerfile
+          context: .
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}