Improve error reporting for bad requests

Author: Peter Amstutz

wes_service/arvados_wes.py

@@ -197,6 +197,7 @@ def RunWorkflow(self, **args):
                                                     "output_path": "n/a",
                                                     "priority": 500}}).execute()
 
+        success = False
         try:
             tempdir, body = self.collect_attachments(cr["uuid"])
 
@@ -210,14 +211,22 @@ def RunWorkflow(self, **args):
                                                                   env,
                                                                   project_uuid,
                                                                   tempdir)).start()
-
+            success = True
+        except ValueError as e:
+            self.log_for_run(cr["uuid"], "Bad request: " + str(e))
+            cr = api.container_requests().update(uuid=cr["uuid"],
+                                                 body={"container_request":
+                                                       {"priority": 0}}).execute()
+            return {"msg": str(e), "status_code": 400}, 400
         except Exception as e:
             logging.exception("Error")
             self.log_for_run(cr["uuid"], "An exception ocurred while handling your request: " + str(e))
             cr = api.container_requests().update(uuid=cr["uuid"],
                                                  body={"container_request":
                                                        {"priority": 0}}).execute()
-        return {"run_id": cr["uuid"]}
+            return {"msg": str(e), "status_code": 500}, 500
+        else:
+            return {"run_id": cr["uuid"]}
 
     @catch_exceptions
     def GetRunLog(self, run_id):

wes_service/util.py

@@ -49,6 +49,7 @@ def log_for_run(self, run_id, message):
     def collect_attachments(self, run_id=None):
         tempdir = tempfile.mkdtemp()
         body = {}
+        has_attachments = False
         for k, ls in iterlists(connexion.request.files):
             for v in ls:
                 if k == "workflow_attachment":
@@ -62,7 +63,7 @@ def collect_attachments(self, run_id=None):
                         os.makedirs(os.path.dirname(dest))
                     self.log_for_run(run_id, "Staging attachment '%s' to '%s'" % (v.filename, dest))
                     v.save(dest)
-                    body[k] = "file://%s" % tempdir  # Reference to temp working dir.
+                    has_attachments = True
                 elif k in ("workflow_params", "tags", "workflow_engine_parameters"):
                     content = v.read()
                     body[k] = json.loads(content.decode("utf-8"))
@@ -77,9 +78,11 @@ def collect_attachments(self, run_id=None):
 
         if "workflow_url" in body:
             if ":" not in body["workflow_url"]:
+                if not has_attachments:
+                    raise ValueError("Relative 'workflow_url' but missing 'workflow_attachment'")
                 body["workflow_url"] = "file://%s" % os.path.join(tempdir, secure_filename(body["workflow_url"]))
             self.log_for_run(run_id, "Using workflow_url '%s'" % body.get("workflow_url"))
         else:
-            raise Exception("Missing 'workflow_url' in submission")
+            raise ValueError("Missing 'workflow_url' in submission")
 
         return tempdir, body