Better error reporting from the master to neoctl for denied requests

This stops abusing ProtocolError, which disconnects the admin node needlessly.

The many 'if ... raise RuntimeError' in neo/neoctl/neoctl.py
could be turned into assertions.

neo/lib/handler.py

@@ -26,6 +26,9 @@ from .protocol import (NodeStates, NodeTypes, Packets, uuid_str,
 from .util import cached_property
 
 
+class AnswerDenied(Exception):
+    """Helper exception to stop packet processing and answer a Denied error"""
+
 class DelayEvent(Exception):
     pass
 
@@ -98,6 +101,8 @@ class EventHandler(object):
                 % (m.im_class.__module__, m.im_class.__name__, m.__name__)))
         except NonReadableCell, e:
             conn.answer(Errors.NonReadableCell())
+        except AnswerDenied, e:
+            conn.answer(Errors.Denied(str(e)))
         except AssertionError:
             e = sys.exc_info()
             try:

neo/lib/protocol.py

@@ -62,6 +62,7 @@ class Enum(tuple):
 @Enum
 def ErrorCodes():
     ACK
+    DENIED
     NOT_READY
     OID_NOT_FOUND
     TID_NOT_FOUND

neo/master/handlers/administration.py

@@ -21,9 +21,10 @@ from . import MasterHandler
 from ..app import monotonic_time, StateChangedException
 from neo.lib import logging
 from neo.lib.exception import StoppedOperation
+from neo.lib.handler import AnswerDenied
 from neo.lib.pt import PartitionTableException
 from neo.lib.protocol import ClusterStates, Errors, \
-    NodeStates, NodeTypes, Packets, ProtocolError, uuid_str
+    NodeStates, NodeTypes, Packets, uuid_str
 from neo.lib.util import dump
 
 CLUSTER_STATE_WORKFLOW = {
@@ -44,8 +45,8 @@ def check_state(*states):
         def wrapper(self, *args):
             state = self.app.getClusterState()
             if state not in states:
-                raise ProtocolError('%s RPC can not be used in %s state'
-                                    % (wrapped.__name__, state))
+                raise AnswerDenied('%s RPC can not be used in %s state'
+                                   % (wrapped.__name__, state))
             wrapped(self, *args)
         return wraps(wrapped)(wrapper)
     return decorator
@@ -75,30 +76,28 @@ class AdministrationHandler(MasterHandler):
         # check request
         try:
             if app.cluster_state not in CLUSTER_STATE_WORKFLOW[state]:
-                raise ProtocolError('Can not switch to this state')
+                raise AnswerDenied('Can not switch to this state')
         except KeyError:
             if state != ClusterStates.STOPPING:
-                raise ProtocolError('Invalid state requested')
+                raise AnswerDenied('Invalid state requested')
 
         # change state
         if state == ClusterStates.VERIFYING:
             storage_list = app.nm.getStorageList(only_identified=True)
             if not storage_list:
-                raise ProtocolError('Cannot exit recovery without any '
-                    'storage node')
+                raise AnswerDenied(
+                    'Cannot exit recovery without any storage node')
             for node in storage_list:
                 assert node.isPending(), node
                 if node.getConnection().isPending():
-                    # XXX: It's wrong to use ProtocolError here. We must reply
-                    #      less aggressively because the admin has no way to
-                    #      know that there's still pending activity.
-                    raise ProtocolError('Cannot exit recovery now: node %r is '
-                        'entering cluster' % (node, ))
+                    raise AnswerDenied(
+                        'Cannot exit recovery now: node %r is entering cluster'
+                        % node,)
             app._startup_allowed = True
             state = app.cluster_state
         elif state == ClusterStates.STARTING_BACKUP:
             if app.tm.hasPending() or app.nm.getClientList(True):
-                raise ProtocolError("Can not switch to %s state with pending"
+                raise AnswerDenied("Can not switch to %s state with pending"
                     " transactions or connected clients" % state)
 
         conn.answer(Errors.Ack('Cluster state changed'))
@@ -110,11 +109,11 @@ class AdministrationHandler(MasterHandler):
         app = self.app
         node = app.nm.getByUUID(uuid)
         if node is None:
-            raise ProtocolError('unknown node')
+            raise AnswerDenied('unknown node')
         if state not in NODE_STATE_WORKFLOW.get(node.getType(), ()):
-            raise ProtocolError('can not switch node to this state')
+            raise AnswerDenied('can not switch node to %s state' % state)
         if uuid == app.uuid:
-            raise ProtocolError('can not kill primary master node')
+            raise AnswerDenied('can not kill primary master node')
 
         state_changed = state != node.getState()
         message = ('state changed' if state_changed else
@@ -124,7 +123,7 @@ class AdministrationHandler(MasterHandler):
             try:
                 cell_list = app.pt.dropNodeList([node], keep)
             except PartitionTableException, e:
-                raise ProtocolError(str(e))
+                raise AnswerDenied(str(e))
             node.setState(state)
             if node.isConnected():
                 # notify itself so it can shutdown
@@ -183,7 +182,7 @@ class AdministrationHandler(MasterHandler):
         for uuid in uuid_list:
             node = getByUUID(uuid)
             if node is None or not (node.isStorage() and node.isIdentified()):
-                raise ProtocolError("invalid storage node %s" % uuid_str(uuid))
+                raise AnswerDenied("invalid storage node %s" % uuid_str(uuid))
             node_list.append(node)
         repair = Packets.NotifyRepair(*args)
         for node in node_list:

neo/neoctl/handler.py

@@ -14,6 +14,7 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+import sys
 from neo.lib.handler import EventHandler
 from neo.lib.protocol import ErrorCodes, Packets
 
@@ -44,8 +45,8 @@ class CommandEventHandler(EventHandler):
     def ack(self, conn, msg):
         self.__respond((Packets.Error, ErrorCodes.ACK, msg))
 
-    def protocolError(self, conn, msg):
-        self.__respond((Packets.Error, ErrorCodes.PROTOCOL_ERROR, msg))
+    def denied(self, conn, msg):
+        sys.exit(msg)
 
     def notReady(self, conn, msg):
         self.__respond((Packets.Error, ErrorCodes.NOT_READY, msg))

neo/tests/functional/__init__.py

@@ -433,7 +433,7 @@ class NEOCluster(object):
                         pending_count += 1
                     if pending_count == target[0]:
                         neoctl.startCluster()
-            except (NotReadyException, RuntimeError):
+            except (NotReadyException, SystemExit):
                 pass
         if not pdb.wait(test, MAX_START_TIME):
             raise AssertionError('Timeout when starting cluster')
@@ -445,7 +445,7 @@ class NEOCluster(object):
         def start(last_try):
             try:
                 self.neoctl.startCluster()
-            except (NotReadyException, RuntimeError), e:
+            except (NotReadyException, SystemExit), e:
                 return False, e
             return True, None
         self.expectCondition(start)

neo/tests/functional/testMaster.py

@@ -47,7 +47,7 @@ class MasterTests(NEOFunctionalTest):
                 break
         neoctl.killNode(uuid)
         self.neo.expectDead(master)
-        self.assertRaises(RuntimeError, neoctl.killNode, primary_uuid)
+        self.assertRaises(SystemExit, neoctl.killNode, primary_uuid)
 
     def testStoppingPrimaryWithTwoSecondaries(self):
         # Wait for masters to stabilize

neo/tests/functional/testStorage.py

@@ -172,7 +172,7 @@ class StorageTests(NEOFunctionalTest):
         self.neo.expectOudatedCells(2)
         self.neo.expectClusterRunning()
 
-        self.assertRaises(RuntimeError, self.neo.neoctl.killNode,
+        self.assertRaises(SystemExit, self.neo.neoctl.killNode,
             started[1].getUUID())
         started[1].stop()
         # Cluster not operational anymore. Only cells of second storage that
@@ -323,7 +323,7 @@ class StorageTests(NEOFunctionalTest):
         self.neo.expectStorageUnknown(started[0])
         self.neo.expectAssignedCells(started[0], 0)
         self.neo.expectAssignedCells(started[1], 10)
-        self.assertRaises(RuntimeError, self.neo.neoctl.dropNode,
+        self.assertRaises(SystemExit, self.neo.neoctl.dropNode,
                           started[1].getUUID())
         self.neo.expectClusterRunning()
 

neo/tests/threaded/__init__.py

@@ -934,7 +934,7 @@ class NEOCluster(object):
     def startCluster(self):
         try:
             self.neoctl.startCluster()
-        except RuntimeError:
+        except SystemExit:
             Serialized.tic()
             if self.neoctl.getClusterState() not in (
                       ClusterStates.BACKINGUP,