Add push-container workflow

.github/workflows/push-container.yml

@@ -0,0 +1,57 @@
+name: Push Container
+
+on:
+  workflow_run:
+    workflows: ["Linting"]
+    branches:
+      - main
+    types:
+      - completed
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+    if: github.event.workflow_run.conclusion == 'success' && github.event.workflow_run.event == 'push'
+    name: Build & Push Container
+
+    steps:
+      # Create a commit SHA-based tag for the container repositories
+      - name: Create SHA Container Tag
+        id: sha_tag
+        run: |
+          tag=$(cut -c 1-7 <<< $GITHUB_SHA)
+          echo "::set-output name=tag::$tag"
+
+      # Check out the current repository in the `cloudflare-ddns-docker` subdirectory
+      - name: Checkout code
+        uses: actions/checkout@v2
+        with:
+          path: cloudflare-ddns-docker
+
+      - 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: ${{ secrets.GHCR_TOKEN  }}
+
+      # Build and push the container to the GitHub Container
+      # Repository. The container will be tagged as "latest"
+      # and with the short SHA of the commit.
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: cloudflare-ddns-docker/
+          file: cloudflare-ddns-docker/Dockerfile
+          push: true
+          cache-from: type=registry,ref=ghcr.io/akarys42/cloudflare-ddns-docker:latest
+          cache-to: type=inline
+          tags: |
+            ghcr.io/akarys42/cloudflare-ddns-docker:latest
+            ghcr.io/akarys42/cloudflare-ddns-docker:${{ steps.sha_tag.outputs.tag }}
+          build-args: |
+            git_sha=${{ github.sha }}