chore: Publish container image on release (#285)

.github/workflows/build-image.yaml

@@ -0,0 +1,39 @@
+---
+name: publish container image
+
+on:
+  push:
+    branches:
+      - master
+  release:
+    types:
+      - created
+  workflow_dispatch:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Set tag for image
+        run: |
+          echo IMAGE_TAG=$([ ${{ github.ref_type }} == 'tag' ] && echo ${{ github.ref_name }} || echo 'latest') >> $GITHUB_ENV
+      - name: Build and Push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          platforms: linux/amd64
+          push: true
+          tags: |
+            ghcr.io/${{ github.repository }}:${{ env.IMAGE_TAG }}