Merge pull request #30 from sagikazarmark/publish-docker-image

Add GitHub Actions build for publishing container image

.github/.editorconfig

@@ -0,0 +1,2 @@
+[{*.yml,*.yaml}]
+indent_size = 2

.github/workflows/docker.yaml

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+name: Docker
+
+on:
+  push:
+    branches:
+      - master
+    tags:
+      - v[0-9]+.[0-9]+.[0-9]+
+  pull_request:
+
+jobs:
+  docker:
+    name: Docker
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Calculate Docker image tags
+        id: tags
+        env:
+          DOCKER_IMAGES: "ghcr.io/${{ github.repository }}"
+        run: |
+          case $GITHUB_REF in
+            refs/tags/*)  VERSION=${GITHUB_REF#refs/tags/};;
+            refs/heads/*) VERSION=$(echo ${GITHUB_REF#refs/heads/} | sed -r 's#/+#-#g');;
+            refs/pull/*)  VERSION=pr-${{ github.event.number }};;
+            *)            VERSION=sha-${GITHUB_SHA::8};;
+          esac
+
+          TAGS=()
+          for image in $DOCKER_IMAGES; do
+            TAGS+=("${image}:${VERSION}")
+
+            if [[ "${{ github.event.repository.default_branch }}" == "$VERSION" ]]; then
+              TAGS+=("${image}:latest")
+            fi
+          done
+
+          echo ::set-output name=version::${VERSION}
+          echo ::set-output name=tags::$(IFS=,; echo "${TAGS[*]}")
+          echo ::set-output name=build_date::$(git show -s --format=%cI)
+
+      - 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.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+        if: github.event_name == 'push'
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          push: ${{ github.event_name == 'push' }}
+          tags: ${{ steps.tags.outputs.tags }}
+          context: worker/
+          labels: |
+            org.opencontainers.image.title=${{ github.event.repository.name }}
+            org.opencontainers.image.description=${{ github.event.repository.description }}
+            org.opencontainers.image.url=${{ github.event.repository.html_url }}
+            org.opencontainers.image.source=${{ github.event.repository.clone_url }}
+            org.opencontainers.image.version=${{ steps.tags.outputs.version }}
+            org.opencontainers.image.created=${{ steps.tags.outputs.build_date }}
+            org.opencontainers.image.revision=${{ github.sha }}
+            org.opencontainers.image.licenses=${{ github.event.repository.license.spdx_id }}