ci: add job to build docker image (#2)

Author: milkrage

.github/workflows/build.yaml

@@ -0,0 +1,42 @@
+---
+name: build
+
+on:
+  push:
+    tags: [ '*' ]
+
+jobs:
+  # Reference:
+  # https://docs.github.com/en/actions/use-cases-and-examples/publishing-packages/publishing-docker-images#publishing-images-to-github-packages
+  build-and-push-image:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: write
+      attestations: write
+      id-token: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Log in to the Container registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v5
+        with:
+          images: ghcr.io/${{ github.repository }}
+
+      - name: Build and push Docker image
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: ${{ steps.meta.outputs.tags }}