ci: secret job to check for invalid secrets

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

.github/workflows/ci.yml

@@ -302,6 +302,29 @@ jobs:
         run: |
           docker image inspect myimage:latest
 
+  secret:
+    runs-on: ubuntu-latest
+    steps:
+      -
+        name: Checkout
+        uses: actions/checkout@v3
+      -
+        name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+        with:
+          version: ${{ inputs.buildx-version || env.BUILDX_VERSION }}
+          driver-opts: |
+            image=${{ inputs.buildkit-image || env.BUILDKIT_IMAGE }}
+      -
+        name: Build
+        uses: ./
+        with:
+          context: .
+          file: ./test/secret.Dockerfile
+          secrets: |
+            MYSECRET=foo
+            INVALID_SECRET=
+
   network:
     runs-on: ubuntu-latest
     steps: