updated dev build

.github/workflows/dev-buildx.yml

@@ -0,0 +1,57 @@
+name: dev-buildx
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: clone https://github.com/heywoodlh/dockerfiles
+        uses: actions/checkout@master
+        with:
+          name: heywoodlh/dockerfiles
+          repository: heywoodlh/dockerfiles
+          path: ./dockerfiles
+
+      -
+        name: Set up QEMU
+        uses: docker/setup-qemu-action@v1
+
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      -
+        name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      -
+        name: Install nix
+        uses: cachix/install-nix-action@v27
+        with:
+          github_access_token: ${{ secrets.GITHUB_TOKEN }}
+
+      -
+        name: Setup nix magic cache
+        uses: DeterminateSystems/magic-nix-cache-action@main
+
+      -
+        name: Update flake
+        run: |
+          cd dockerfiles/dev
+          nix flake update
+          git add flake.lock
+
+      -
+        name: Get current month
+        run: echo date=$(date +%Y_%m) >> $GITHUB_ENV
+
+      -
+        name: Build and push heywoodlh/dev
+        uses: docker/build-push-action@v2
+        with:
+          platforms: linux/amd64,linux/arm64
+          push: true
+          tags: heywoodlh/dev:latest,heywoodlh/dev:${{ env.date }}