Add smoke test for Docker container sanity (#205)

And fix the failure we just introduced in the last patch

Author: ldionne

.github/workflows/build-docker.yaml

@@ -37,3 +37,20 @@ jobs:
         file: docker/lnt.dockerfile
         # Use the current directory as context, as checked out by actions/checkout -- needed for setuptools_scm
         context: .
+
+    - name: Smoke test - start server and ping it
+      run: |
+        docker compose -f docker/compose.yaml up --build --detach
+        timeout 120 bash -c 'until curl -sf http://localhost:8000; do sleep 2; done'
+        curl -f http://localhost:8000
+      env:
+        LNT_DB_PASSWORD: smoke-test-password
+        LNT_AUTH_TOKEN: smoke-test-token
+
+    - name: Dump logs on failure
+      if: failure()
+      run: docker compose -f docker/compose.yaml logs
+
+    - name: Teardown
+      if: always()
+      run: docker compose -f docker/compose.yaml down

docker/compose.yaml

@@ -56,7 +56,7 @@ services:
     volumes:
       - instance:/var/lib/lnt
     ports:
-      - "8000"
+      - "8000:8000"
     networks:
       - lnt_network