Skip loading (and failing to load) lock files

Ignore lock files (and other hidden files) that zookeeper
will notify the jobboard about and avoid reading these as
potential jobs (which they are not).

Fixes bug 1312843

Change-Id: Ifa1ed31e22aed838f9baf883a6faaec00187663a

taskflow/jobs/backends/impl_zookeeper.py

@@ -49,6 +49,8 @@ ALL_JOB_STATES = (
 
 # Transaction support was added in 3.4.0
 MIN_ZK_VERSION = (3, 4, 0)
+LOCK_POSTFIX = ".lock"
+JOB_PREFIX = 'job'
 
 
 def _check_who(who):
@@ -74,7 +76,7 @@ class ZookeeperJob(base_job.Job):
             raise ValueError("Only one of 'book_data' or 'book'"
                              " can be provided")
         self._path = path
-        self._lock_path = "%s.lock" % (path)
+        self._lock_path = path + LOCK_POSTFIX
         self._created_on = created_on
         self._node_not_found = False
 
@@ -232,7 +234,7 @@ class ZookeeperJobBoard(jobboard.NotifyingJobBoard):
         self._job_watcher = None
         # Since we use sequenced ids this will be the path that the sequences
         # are prefixed with, for example, job0000000001, job0000000002, ...
-        self._job_base = k_paths.join(path, "job")
+        self._job_base = k_paths.join(path, JOB_PREFIX)
         self._worker = None
         self._emit_notifications = bool(emit_notifications)
 
@@ -331,7 +333,12 @@ class ZookeeperJobBoard(jobboard.NotifyingJobBoard):
 
     def _on_job_posting(self, children, delayed=True):
         LOG.debug("Got children %s under path %s", children, self.path)
-        child_paths = [k_paths.join(self.path, c) for c in children]
+        child_paths = []
+        for c in children:
+            if c.endswith(LOCK_POSTFIX) or not c.startswith(JOB_PREFIX):
+                # Skip lock paths or non-job-paths (these are not valid jobs)
+                continue
+            child_paths.append(k_paths.join(self.path, c))
 
         # Remove jobs that we know about but which are no longer children
         with self._job_mutate: