ADD: publish docker image in Github Container Registry

Author: fileformat

.github/workflows/build.yaml

@@ -0,0 +1,47 @@
+name: build
+
+on:
+  push:
+    branches:
+    - main
+
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Login to GitHub Container Registry
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Set some env vars for the build
+        run: |
+          TIMESTAMP=$(date -u +%Y-%m-%dT%H:%M:%SZ)
+          echo "COMMIT=${GITHUB_SHA:0:7}" >> $GITHUB_ENV
+          echo "LASTMOD=${TIMESTAMP}" >> $GITHUB_ENV
+          echo "IMAGE_NAME=redirect2me/siterank" >> $GITHUB_ENV
+
+      - name: Build and push
+        uses: docker/build-push-action@v5
+        with:
+          context: .
+          file: ./Dockerfile
+          push: true
+          tags: |
+            ghcr.io/${{ env.IMAGE_NAME }}:${{ env.VERSION }}
+            ghcr.io/${{ env.IMAGE_NAME }}:latest
+          build-args: |
+            COMMIT=${{ env.COMMIT }}
+            LASTMOD=${{ env.LASTMOD }}
+