Separate merger/server pidfile/logging better

So that they may safely coexist on a single host.

Change-Id: I64698423670bf11051c40ad80427643dd0f3d0cd

doc/source/zuul.rst

@@ -87,11 +87,11 @@ zuul
   ``layout_config=/etc/zuul/layout.yaml``
 
 **log_config**
-  Path to log config file.  Used by all Zuul commands.
+  Path to log config file.  Used by zuul-server only.
   ``log_config=/etc/zuul/logging.yaml``
 
 **pidfile**
-  Path to PID lock file.  Used by all Zuul commands.
+  Path to PID lock file.  Used by zuul-server only.
   ``pidfile=/var/run/zuul/zuul.pid``
 
 **state_dir**
@@ -143,6 +143,14 @@ merger
   "http://zuul.example.com/p" or "http://zuul-merger01.example.com/p"
   depending on whether the merger is co-located with the Zuul server.
 
+**log_config**
+  Path to log config file for the merger process.
+  ``log_config=/etc/zuul/logging.yaml``
+
+**pidfile**
+  Path to PID lock file for the merger process.
+  ``pidfile=/var/run/zuul-merger/merger.pid``
+
 smtp
 """"
 

zuul/cmd/merger.py

@@ -94,7 +94,7 @@ class Merger(object):
         # See comment at top of file about zuul imports
         import zuul.merger.server
 
-        self.setup_logging('zuul', 'log_config')
+        self.setup_logging('merger', 'log_config')
 
         self.merger = zuul.merger.server.MergeServer(self.config)
         self.merger.start()
@@ -135,10 +135,10 @@ def main():
         print
         raise
 
-    if server.config.has_option('zuul', 'pidfile'):
-        pid_fn = os.path.expanduser(server.config.get('zuul', 'pidfile'))
+    if server.config.has_option('merger', 'pidfile'):
+        pid_fn = os.path.expanduser(server.config.get('merger', 'pidfile'))
     else:
-        pid_fn = '/var/run/zuul/merger.pid'
+        pid_fn = '/var/run/zuul-merger/merger.pid'
     pid = pid_file_module.TimeoutPIDLockFile(pid_fn, 10)
 
     if server.args.nodaemon: