the pipeline shall still be created even when no computational service is in the pipeline (#2105)

Author: sanderegg

services/director-v2/src/simcore_service_director_v2/api/routes/computations.py

@@ -132,13 +132,6 @@ async def create_computation(
                 detail=f"Project {job.project_id} is not a valid directed acyclic graph!",
             )
 
-        if not dag_graph.nodes():
-            # there is nothing else to be run here, so we are done
-            raise HTTPException(
-                status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
-                detail=f"Project {job.project_id} has no computational services",
-            )
-
         # ok so put the tasks in the db
         await computation_pipelines.upsert_pipeline(
             project.uuid, dag_graph, job.start_pipeline
@@ -150,6 +143,12 @@ async def create_computation(
         )
 
         if job.start_pipeline:
+            if not dag_graph.nodes():
+                # there is nothing else to be run here, so we are done
+                raise HTTPException(
+                    status_code=status.HTTP_422_UNPROCESSABLE_ENTITY,
+                    detail=f"Project {job.project_id} has no computational services",
+                )
             # trigger celery
             task = celery_client.send_computation_task(job.user_id, job.project_id)
             background_tasks.add_task(background_on_message, task)

services/director-v2/tests/integration/test_computation_api.py

@@ -587,3 +587,47 @@ def test_update_and_delete_computation(
     assert (
         response.status_code == status.HTTP_204_NO_CONTENT
     ), f"response code is {response.status_code}, error: {response.text}"
+
+
+def test_pipeline_with_no_comp_services_still_create_correct_comp_tasks(
+    client: TestClient,
+    user_id: PositiveInt,
+    project: Callable,
+    jupyter_service: Dict[str, str],
+):
+    # create a workbench with just a dynamic service
+    project_with_dynamic_node = project(
+        workbench={
+            "39e92f80-9286-5612-85d1-639fa47ec57d": {
+                "key": jupyter_service["image"]["name"],
+                "version": jupyter_service["image"]["tag"],
+                "label": "my sole dynamic service",
+            }
+        }
+    )
+
+    # this pipeline is not runnable as there are no computational services
+    response = client.post(
+        COMPUTATION_URL,
+        json={
+            "user_id": user_id,
+            "project_id": str(project_with_dynamic_node.uuid),
+            "start_pipeline": True,
+        },
+    )
+    assert (
+        response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+    ), f"response code is {response.status_code}, error: {response.text}"
+
+    # still this pipeline shall be createable if we do not want to start it
+    response = client.post(
+        COMPUTATION_URL,
+        json={
+            "user_id": user_id,
+            "project_id": str(project_with_dynamic_node.uuid),
+            "start_pipeline": False,
+        },
+    )
+    assert (
+        response.status_code == status.HTTP_201_CREATED
+    ), f"response code is {response.status_code}, error: {response.text}"