use job id for swarm run instead of job object

app/services/views.py

@@ -48,8 +48,7 @@ def nlp():
             ' NOTE: Using self created threads is just for testing purpose as
             '       there is no scheduler available.
             '''
-            db.session.expunge(nlp_job)
-            thread = Thread(target=swarm.run, args=(nlp_job,))
+            thread = Thread(target=swarm.run, args=(nlp_job.id,))
             thread.start()
             flash('Job created!')
         return redirect(url_for('services.nlp'))
@@ -101,8 +100,7 @@ def ocr():
             ' NOTE: Using self created threads is just for testing purpose as
             '       there is no scheduler available.
             '''
-            db.session.expunge(ocr_job)
-            thread = Thread(target=swarm.run, args=(ocr_job,))
+            thread = Thread(target=swarm.run, args=(ocr_job.id,))
             thread.start()
             flash('Job created!')
         return redirect(url_for('services.ocr'))

app/swarm.py

@@ -30,10 +30,13 @@ class Swarm:
     ' ¹ https://blog.alexellis.io/containers-on-swarm/
     '''
 
-    def run(self, job):
+    def run(self, job_id):
         '''
-        Input is a job object. From this the _command is built.
+        Input is a job id.
         '''
+        from .models import Job
+        session = self.Session()
+        job = session.query(Job).filter_by(id=job_id).first()
         # Prepare argument values needed for the service creation.
         service_args = json.loads(job.service_args)
         _command = (job.service
@@ -98,9 +101,9 @@ class Swarm:
             time.sleep(1)
             service.reload()
         '''
+        ' The following is scheduler work.
         ' Poll the service until the job is completly executed.
         '''
-        session = self.Session()
         session.add(job)
         job.status = 'running'
         session.commit()