Use a hash for lock names

Some tooz drivers do not support long lock names. For example, mysql locks must
be 64 characters at most. This hashes the lock name in order to fix the lock
name length.

Change-Id: I5f058ea1197f5c2ba062a9bc0b67c509c8252852

cloudkitty/orchestrator.py

@@ -16,6 +16,7 @@
 # @author: Stéphane Albert
 #
 import decimal
+import hashlib
 import multiprocessing
 import random
 import sys
@@ -282,11 +283,12 @@ class Orchestrator(cotyledon.Service):
         self.coord.start(start_heart=True)
 
     def _lock(self, tenant_id):
-        name = b"cloudkitty-" \
-            + str(tenant_id + '-').encode('ascii') \
-            + str(CONF.collect.collector + '-').encode('ascii') \
-            + str(CONF.fetcher.backend + '-').encode('ascii') \
-            + str(CONF.collect.scope_key).encode('ascii')
+        name = hashlib.sha256(
+            ("cloudkitty-"
+             + str(tenant_id + '-')
+             + str(CONF.collect.collector + '-')
+             + str(CONF.fetcher.backend + '-')
+             + str(CONF.collect.scope_key)).encode('ascii')).hexdigest()
         return name, self.coord.get_lock(name)
 
     def _init_messaging(self):
@@ -332,7 +334,6 @@ class Orchestrator(cotyledon.Service):
                         '[Worker: {w}] Acquired lock "{l}" ...'.format(
                             w=self._worker_id, l=lock_name)
                     )
-                    LOG.debug('Acquired lock "{}".'.format(lock_name))
                     state = self._check_state(tenant_id)
                     if state:
                         worker = Worker(