add create_workflow_task to handler and scheduler

jupyter_scheduler/scheduler.py

@@ -46,7 +46,7 @@
     create_output_directory,
     create_output_filename,
 )
-from jupyter_scheduler.workflows import CreateWorkflow, DescribeWorkflow
+from jupyter_scheduler.workflows import CreateWorkflow, DescribeWorkflow, UpdateWorkflow
 
 
 class BaseScheduler(LoggingConfigurable):
@@ -124,6 +124,10 @@ def get_workflow(self, workflow_id: str) -> DescribeWorkflow:
         """Returns workflow record for a single workflow."""
         raise NotImplementedError("must be implemented by subclass")
 
+    def create_workflow_task(self, workflow_id: str, model: CreateJob) -> str:
+        """Adds a task to a workflow."""
+        raise NotImplementedError("must be implemented by subclass")
+
     def update_job(self, job_id: str, model: UpdateJob):
         """Updates job metadata in the persistence store,
         for example name, status etc. In case of status
@@ -565,6 +569,14 @@ def get_workflow(self, workflow_id: str) -> DescribeWorkflow:
         model = DescribeWorkflow.from_orm(workflow_record)
         return model
 
+    def create_workflow_task(self, workflow_id: str, model: CreateJob) -> str:
+        job_id = self.scheduler.create_job(model, run=False)
+        workflow: DescribeWorkflow = self.scheduler.get_workflow(workflow_id)
+        updated_tasks = (workflow.tasks or [])[:]
+        updated_tasks.append(job_id)
+        self.scheduler.update_workflow(workflow_id, UpdateWorkflow(depends_on=updated_tasks))
+        return job_id
+
     def update_job(self, job_id: str, model: UpdateJob):
         with self.db_session() as session:
             session.query(Job).filter(Job.job_id == job_id).update(model.dict(exclude_none=True))

jupyter_scheduler/workflows.py

@@ -1,5 +1,5 @@
 import json
-from typing import List
+from typing import List, Optional
 
 from jupyter_server.utils import ensure_async
 from tornado.web import HTTPError, authenticated
@@ -71,7 +71,11 @@ async def post(self, workflow_id: str):
                 "Error during workflow job creation. workflow_id in the URL and payload don't match.",
             )
         try:
-            job_id = await ensure_async(self.scheduler.create_job(CreateJob(**payload), run=False))
+            job_id = await ensure_async(
+                self.scheduler.create_workflow_task(
+                    workflow_id=workflow_id, model=CreateJob(**payload)
+                )
+            )
         except ValidationError as e:
             self.log.exception(e)
             raise HTTPError(500, str(e)) from e
@@ -175,3 +179,10 @@ class UpdateWorkflow(BaseModel):
 
     class Config:
         orm_mode = True
+
+
+class UpdateWorkflow(BaseModel):
+    status: Optional[Status] = None
+    name: Optional[str] = None
+    compute_type: Optional[str] = None
+    depends_on: Optional[str] = None