status: retrieve job status from Job table

* Reads job status from Job table to get the running jobs
  as the `job_progress` in the Workflow table is not correctly
  updated, finished jobs are reported as running creating an exception
  while trying to delete a job which doesn't exist (for more see
  reanahub#299)
  (closes reanahub/reana#266).

reana_workflow_controller/workflow_run_manager.py

@@ -29,7 +29,7 @@
                                  create_cvmfs_storage_class, format_cmd)
 from reana_db.config import SQLALCHEMY_DATABASE_URI
 from reana_db.database import Session
-from reana_db.models import Job
+from reana_db.models import Job, JobStatus
 
 from reana_workflow_controller.errors import (REANAInteractiveSessionError,
                                               REANAWorkflowControllerError)
@@ -221,9 +221,9 @@ def _workflow_engine_env_vars(self):
     def get_workflow_running_jobs_as_backend_ids(self):
         """Get all running jobs of a workflow as backend job IDs."""
         session = Session.object_session(self.workflow)
-        job_list = self.workflow.job_progress.get(
-            'running', {}).get('job_ids', [])
-        rows = session.query(Job).filter(Job.id_.in_(job_list))
+        rows = session.query(Job).filter_by(
+            workflow_uuid=str(self.workflow.id_),
+            status=JobStatus.running)
         backend_ids = [j.backend_job_id for j in rows.all()]
         return backend_ids