Fix pylint warnings

.pylintrc

@@ -219,10 +219,10 @@ class-attribute-rgx=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
 class-attribute-name-hint=([A-Za-z_][A-Za-z0-9_]{2,30}|(__.*__))$
 
 # Regular expression matching correct constant names
-const-rgx=(([A-Z_][A-Z0-9_]*)|(__.*__)|log|([A-Z][A-Za-z]*Type))$
+const-rgx=(([A-Z_][A-Za-z0-9_]*)|(__.*__)|log|([A-Z][A-Za-z]*Type))$
 
 # Naming hint for constant names
-const-name-hint=(([A-Z_][A-Z0-9_]*)|(__.*__)|log|([A-Z][A-Za-z]*Type))$
+const-name-hint=(([A-Z_][A-Za-z0-9_]*)|(__.*__)|log|([A-Z][A-Za-z]*Type))$
 
 # Regular expression matching correct attribute names
 attr-rgx=([a-z_][a-z0-9_]{2,30}|id)$
@@ -254,7 +254,7 @@ notes=FIXME,TODO
 [DESIGN]
 
 # Maximum number of arguments for function / method
-max-args=5
+max-args=7
 
 # Argument names that match this expression will be ignored. Default to name
 # with leading underscore

zoe_api/rest_api/service.py

@@ -19,8 +19,6 @@ from concurrent.futures import ThreadPoolExecutor
 import logging
 
 from tornado.web import RequestHandler
-import tornado.gen
-import tornado.iostream
 
 from zoe_api.rest_api.utils import catch_exceptions, get_auth
 from zoe_api.api_endpoint import APIEndpoint  # pylint: disable=unused-import
@@ -38,7 +36,7 @@ class ServiceAPI(RequestHandler):
         self.api_endpoint = kwargs['api_endpoint']  # type: APIEndpoint
 
     @catch_exceptions
-    def get(self, service_id) -> dict:
+    def get(self, service_id):
         """HTTP GET method."""
         uid, role = get_auth(self)
 

zoe_master/backends/base.py

@@ -35,9 +35,11 @@ class BaseBackend:
         raise NotImplementedError
 
     def spawn_service(self, execution: Execution, service: Service, env_subst_dict: Dict):
+        """Create a container for a service."""
         raise NotImplementedError
 
     def terminate_service(self, service: Service) -> None:
+        """Terminate the container corresponding to a service."""
         raise NotImplementedError
 
     def platform_state(self) -> ClusterStats:

zoe_master/backends/old_swarm/backend.py

@@ -27,10 +27,11 @@ from zoe_master.workspace.filesystem import ZoeFSWorkspace
 import zoe_master.backends.common
 import zoe_master.backends.base
 from zoe_master.backends.old_swarm.threads import SwarmMonitor, SwarmStateSynchronizer
-from zoe_master.stats import NodeStats, ClusterStats
+from zoe_master.stats import NodeStats, ClusterStats  # pylint: disable=unused-import
 
 log = logging.getLogger(__name__)
 
+# These two module-level variables hold the references to the monitor and checker threads
 _monitor = None
 _checker = None
 

zoe_master/entrypoint.py

@@ -20,11 +20,12 @@
 import logging
 
 import zoe_lib.config as config
-import zoe_master.scheduler
-import zoe_master.backends.interface
 from zoe_lib.metrics.influxdb import InfluxDBMetricSender
 from zoe_lib.metrics.logging import LogMetricSender
 from zoe_lib.state import SQLManager
+
+import zoe_master.scheduler
+import zoe_master.backends.interface
 from zoe_master.preprocessing import restart_resubmit_scheduler
 from zoe_master.master_api import APIManager
 

zoe_master/master_api.py

@@ -21,9 +21,10 @@ import time
 import zmq
 
 import zoe_lib.config as config
-import zoe_master.preprocessing
 from zoe_lib.metrics.base import BaseMetricSender
 from zoe_lib.state import SQLManager
+
+import zoe_master.preprocessing
 from zoe_master.exceptions import ZoeException
 from zoe_master.scheduler import ZoeBaseScheduler
 

zoe_master/preprocessing.py

@@ -29,11 +29,11 @@ def _digest_application_description(state: SQLManager, execution: Execution):
         total_count = service_descr['total_count']
         elastic_count = total_count - essential_count
         counter = 0
-        for i in range(essential_count):
+        for service_n_ in range(essential_count):
             name = "{}{}".format(service_descr['name'], counter)
             state.service_new(execution.id, name, service_descr['name'], service_descr, True)
             counter += 1
-        for i in range(elastic_count):
+        for service_n_ in range(elastic_count):
             name = "{}{}".format(service_descr['name'], counter)
             state.service_new(execution.id, name, service_descr['name'], service_descr, False)
             counter += 1

zoe_master/scheduler/simulated_platform.py

@@ -19,10 +19,7 @@ class SimulatedNode:
 
     def service_fits(self, service: Service) -> bool:
         """Checks whether a service can fit in this node"""
-        if service.resource_reservation.memory < self.node_free_memory():
-            return True
-        else:
-            return False
+        return service.resource_reservation.memory < self.node_free_memory()
 
     def service_add(self, service):
         """Add a service in this node."""
@@ -56,8 +53,8 @@ class SimulatedNode:
 
     def __repr__(self):
         # services = ','.join([str(s.id) for s in self.services])
-        s = 'SN {} | f {}'.format(self.name, self.node_free_memory())
-        return s
+        out = 'SN {} | f {}'.format(self.name, self.node_free_memory())
+        return out
 
 
 class SimulatedPlatform:
@@ -71,7 +68,7 @@ class SimulatedPlatform:
         """Try to find an allocation for essential services"""
         for service in execution.essential_services:
             candidate_nodes = []
-            for node_name, node in self.nodes.items():
+            for node_id_, node in self.nodes.items():
                 if node.service_fits(service):
                     candidate_nodes.append(node)
             if len(candidate_nodes) == 0:  # this service does not fit anywhere
@@ -84,7 +81,7 @@ class SimulatedPlatform:
     def deallocate_essential(self, execution: Execution):
         """Remove all essential services from the simulated cluster"""
         for service in execution.essential_services:
-            for node_name, node in self.nodes.items():
+            for node_id_, node in self.nodes.items():
                 if node.service_remove(service):
                     break
 
@@ -95,7 +92,7 @@ class SimulatedPlatform:
             if service.status == service.ACTIVE_STATUS:
                 continue
             candidate_nodes = []
-            for node_name, node in self.nodes.items():
+            for node_id_, node in self.nodes.items():
                 if node.service_fits(service):
                     candidate_nodes.append(node)
             if len(candidate_nodes) == 0:  # this service does not fit anywhere
@@ -109,7 +106,7 @@ class SimulatedPlatform:
     def deallocate_elastic(self, execution: Execution):
         """Remove all elastic services from the simulated cluster"""
         for service in execution.elastic_services:
-            for node_name, node in self.nodes.items():
+            for node_id_, node in self.nodes.items():
                 if node.service_remove(service):
                     service.set_inactive()
                     break
@@ -117,8 +114,8 @@ class SimulatedPlatform:
     def aggregated_free_memory(self):
         """Return the amount of free memory across all nodes"""
         total = 0
-        for n_id, n in self.nodes.items():
-            total += n.node_free_memory()
+        for node_id_, node in self.nodes.items():
+            total += node.node_free_memory()
         return total
 
     def get_service_allocation(self):
@@ -130,7 +127,7 @@ class SimulatedPlatform:
         return placements
 
     def __repr__(self):
-        s = ''
-        for node_name, node in self.nodes.items():
-            s += str(node) + " # "
-        return s
+        out = ''
+        for node_id_, node in self.nodes.items():
+            out += str(node) + " # "
+        return out