Added TryJobGerritScheduler

scripts/master/try_job_gerrit.py

Index: scripts/master/try_job_gerrit.py
diff --git a/scripts/master/try_job_gerrit.py b/scripts/master/try_job_gerrit.py
new file mode 100644
index 0000000000000000000000000000000000000000..680e47ccc4e5da58c9a901e931a171c8300493da
--- /dev/null
+++ b/scripts/master/try_job_gerrit.py
@@ -0,0 +1,131 @@
+# Copyright (c) 2014 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import json
+import re
+
+from twisted.internet import defer
+from twisted.python import log
+
+from buildbot.schedulers.base import BaseScheduler
+
+from master.gerrit_poller import GerritPoller
+
+
+class JobDefinition(object):
+  """Describes a try job posted on Gerrit."""
+  def __init__(self, builder_names=None):
+    # Force str type and remove empty builder names.
+    self.builder_names = [str(b) for b in (builder_names or []) if b]
+
+  def __repr__(self):
+    return repr(self.__dict__)
+
+  @staticmethod
+  def parse(text):
+    """Parses a try job definition."""
+    text = text and text.strip()
+    if not text:
+      # Return an empty definition.
+      return JobDefinition()
+
+    # Parse as json.
+    try:
+      job = json.loads(text)
+    except:
+      raise ValueError('Couldn\'t parse job definition: %s' % text)
+
+    # Convert to canonical form.
+    if isinstance(job, list):
+      # Treat a list as builder name list.
+      job = {'builderNames': job}
+    elif not isinstance(job, dict):
+      raise ValueError('Job definition must be a JSON object or array.')
+
+    return JobDefinition(job.get('builderNames'))
+
+
+class _TryJobGerritPoller(GerritPoller):
+  """Polls issues, creates changes and calls scheduler.submitJob.
+
+  This class is a part of TryJobGerritScheduler implementation and not designed
+  to be used otherwise.
+  """
+
+  change_category = 'tryjob'
+
+  MESSAGE_REGEX_TRYJOB = re.compile('Patch set \d+:\s+\!tryjob(.*)', re.I)
+
+  def __init__(self, scheduler, gerrit_host, gerrit_projects=None,
+               pollInterval=None):
+    assert scheduler
+    GerritPoller.__init__(self, gerrit_host, gerrit_projects, pollInterval)
+    self.scheduler = scheduler
+
+  def _is_interesting_message(self, message):
+    return self.MESSAGE_REGEX_TRYJOB.match(message['message'])
+
+  def getChangeQuery(self):
+    query = GerritPoller.getChangeQuery(self)
+    # Request only issues with TryJob=+1 label.
+    query += '+label:TryJob=%2B1'
+    return query
+
+  def parseJob(self, message):
+    """Parses a JobDefinition from a Gerrit message."""
+    tryjob_match = self.MESSAGE_REGEX_TRYJOB.match(message['message'])
+    assert tryjob_match
+    return JobDefinition.parse(tryjob_match.group(1))
+
+  @defer.inlineCallbacks
+  def addChange(self, change, message):
+    """Parses a job, adds a change and calls self.scheduler.submitJob."""
+    try:
+      job = self.parseJob(message)
+      buildbotChange = yield self.addBuildbotChange(change, message)
+      yield self.scheduler.submitJob(buildbotChange, job)
+      defer.returnValue(buildbotChange)
+    except Exception as e:
+      log.err('TryJobGerritPoller failed: %s' % e)
+      raise
+
+
+class TryJobGerritScheduler(BaseScheduler):
+  """Polls try jobs on Gerrit and creates buildsets."""
+  def __init__(self, name, default_builder_names, gerrit_host,
+               gerrit_projects=None, pollInterval=None):
+    """Creates a new TryJobGerritScheduler.
+
+    Args:
+        name: name of the scheduler.
+        default_builder_names: a list of builder names used in case a job didn't
+            specify any.
+        gerrit_host: URL to the Gerrit instance
+        gerrit_projects: Gerrit projects to filter issues.
+        pollInterval: frequency of polling.
+    """
+    BaseScheduler.__init__(self, name,
+                           builderNames=default_builder_names,
+                           properties={})
+    self.poller = _TryJobGerritPoller(self, gerrit_host, gerrit_projects,
+                                      pollInterval)
+
+  def setServiceParent(self, parent):
+    BaseScheduler.setServiceParent(self, parent)
+    self.poller.master = self.master
+    self.poller.setServiceParent(self)
+
+  def gotChange(self, *args, **kwargs):
+    """Do nothing because changes are processed by submitJob."""
+
+  @defer.inlineCallbacks
+  def submitJob(self, change, job):
+    bsid = yield self.addBuildsetForChanges(
+        reason='tryjob',
+        changeids=[change.number],
+        builderNames=job.builder_names,
+        properties=change.properties)
+    log.msg('Successfully submitted a Gerrit try job for %s: %s.' %
+            (change.who, job))
+    defer.returnValue(bsid)