feat: add GitHub Actions workflow for building and pushing Docker images

Author: DemoMacro

.github/workflows/docker-build.yml

@@ -0,0 +1,48 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [main]
+    tags: ["v*"]
+  pull_request:
+    branches: [main]
+  workflow_dispatch:
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+env:
+  IMAGE_NAME: bysages/lens
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      packages: write
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Log in to Docker Hub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+
+      # create a unique tag for each build for debugging
+      - name: Set Docker tag
+        id: date
+        run: echo "date_stamp=$(date +%s)" >> "$GITHUB_OUTPUT"
+
+      - name: Build and push Docker images
+        uses: iloveitaly/github-action-nixpacks@main
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: |
+            ${{ env.IMAGE_NAME }}:latest
+            ${{ env.IMAGE_NAME }}:${{ steps.date.outputs.date_stamp }}
+            ${{ env.IMAGE_NAME }}:${{ github.sha }}