Add more logging to zuul merger process

Add logging to the zuul merger process that includes change numbers so
that threads of execution can be easily tracked from the zuul server log
files to the zuul merger log files.

Change-Id: Ic591f3941d6fe84874e16c8309a101a2918979a2

zuul/merger/merger.py

@@ -195,7 +195,7 @@ class Merger(object):
         try:
             self.log.info("Updating local repository %s", project)
             repo.update()
-        except:
+        except Exception:
             self.log.exception("Unable to update %s", project)
 
     def _mergeChange(self, item, ref):
@@ -282,6 +282,12 @@ class Merger(object):
         recent = {}
         commit = None
         for item in items:
+            if item.get("number") and item.get("patchset"):
+                self.log.debug("Merging for change %s,%s." %
+                               (item["number"], item["patchset"]))
+            elif item.get("newrev") and item.get("oldrev"):
+                self.log.debug("Merging for rev %s with oldrev %s." %
+                               (item["newrev"], item["oldrev"]))
             commit = self._mergeItem(item, recent)
             if not commit:
                 return None

zuul/merger/server.py

@@ -90,8 +90,10 @@ class MergeServer(object):
                 job = self.worker.getJob()
                 try:
                     if job.name == 'merger:merge':
+                        self.log.debug("Got merge job.")
                         self.merge(job)
                     elif job.name == 'merger:update':
+                        self.log.debug("Got update job.")
                         self.update(job)
                     else:
                         self.log.error("Unable to handle job %s" % job.name)

zuul/scheduler.py

@@ -1110,6 +1110,16 @@ class BasePipelineManager(object):
     def _makeMergerItem(self, item):
         # Create a dictionary with all info about the item needed by
         # the merger.
+        number = None
+        patchset = None
+        oldrev = None
+        newrev = None
+        if hasattr(item.change, 'number'):
+            number = item.change.number
+            patchset = item.change.patchset
+        elif hasattr(item.change, 'newrev'):
+            oldrev = item.change.oldrev
+            newrev = item.change.newrev
         return dict(project=item.change.project.name,
                     url=self.pipeline.trigger.getGitUrl(
                         item.change.project),
@@ -1117,6 +1127,10 @@ class BasePipelineManager(object):
                     refspec=item.change.refspec,
                     branch=item.change.branch,
                     ref=item.current_build_set.ref,
+                    number=number,
+                    patchset=patchset,
+                    oldrev=oldrev,
+                    newrev=newrev,
                     )
 
     def prepareRef(self, item):