build(ci): test the image compilation

.devcontainer/devcontainer.json

@@ -11,7 +11,8 @@
 	"settings": {},
 	// Add the IDs of extensions you want installed when the container is created.
 	"extensions": [
-		"ms-azuretools.vscode-docker"
+		"ms-azuretools.vscode-docker",
+		"github.vscode-pull-request-github"
 	],
 	
 	// Use 'forwardPorts' to make a list of ports inside the container available locally.

.github/workflows/build.yml

@@ -0,0 +1,64 @@
+name: Build Container
+
+on:
+  push:
+    branches-ignore:
+      - master
+  pull_request:
+    branches:
+      - master
+
+jobs:
+  check:
+    runs-on: ubuntu-latest
+    outputs:
+      is_new: ${{ steps.check_ver.outputs.is_new }}
+      version: ${{ steps.check_ver.outputs.version }}
+    steps:
+      - name: Check version
+        id: check_ver
+        run: |
+          get_ver() (curl -s "$@" | grep -Po "(\d+\.)+\d+\-r\d+" | head -1)
+          OLD_VER=$(get_ver ${GHCO_URL})
+          NEW_VER=$(get_ver ${ALPINE_PKG_URL})
+          if [ "$NEW_VER" != "$OLD_VER" ]; then
+            echo "::set-output name=is_new::true"
+          else
+            echo "::set-output name=is_new::false"
+          fi
+          echo "::set-output name=version::${NEW_VER}"
+        env:
+          ALPINE_PKG_URL: https://pkgs.alpinelinux.org/package/edge/testing/x86_6
+4/qbittorrent-nox
+          GHCO_URL: https://github.com/mogeko/docker-qbittorrent/pkgs/container/qbittorrent
+
+  build:
+    runs-on: ubuntu-latest
+    needs: check
+    if: ${{ !needs.check.outputs.is_new }}
+    permissions:
+      packages: write
+      contents: read
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+
+      - name: Build image
+        run: |
+          docker build . \
+            --build-arg "VERSION=${{ needs.check.outputs.version }}" \
+            --label "BUILD_ID=${GITHUB_RUN_ID}" \
+            --label "BUILD_SERVER=${GITHUB_SERVER_URL}" \
+            --label "OS=${RUNNER_OS}" \
+            --tag qbittorrent
+      
+      - name: Save status
+        run: docker images > ${{ github.workspace }}/images.txt
+
+      - name: Update status
+        uses: actions/upload-artifact@v2
+        with:
+          name: images
+          path: ${{ github.workspace }}/images.txt