add docker build

.github/workflows/docker_build.yml

@@ -0,0 +1,62 @@
+name: Build Docker image Steam-Watcher
+
+on:
+  schedule:
+    - cron: '0 5 * * 1'
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+concurrency:
+  group: ${{ github.workflow }}
+
+env:
+  TITLE: Steam Watcher
+  # github.repository as <account>/<repo>
+  GHCR_SLUG: ghcr.io/lifeismana/steam-watcher
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      packages: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: |
+            ${{ env.GHCR_SLUG }}
+          labels: |
+            maintainer=${{ github.repository_owner }}
+            org.opencontainers.image.vendor=${{ github.repository_owner }}
+            org.opencontainers.image.title=${{ env.TITLE }}
+
+      - name: Setup Docker buildx
+        uses: docker/[email protected]
+
+      # Login against a Docker registry except on PR
+      # https://github.com/docker/login-action
+      - name: Log into registry
+        if: github.event_name != 'pull_request'
+        uses: docker/[email protected]
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # Build and push Docker image with Buildx (don't push on PR)
+      # https://github.com/docker/build-push-action
+      - name: Build and push Docker image
+        id: build-and-push
+        uses: docker/[email protected]
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ env.GHCR_SLUG }}:latest
+          cache-from: ${{ env.GHCR_SLUG }}:latest
+          labels: ${{ steps.meta.outputs.labels }}