Refactor and simplify metrics collection

varnish-graphite.py

@@ -31,11 +31,11 @@ def connect(self):
 
   def send_metrics(self, metrics):
     for stat in metrics:
-      if len(self.sendbuf) + len(stat) > self.buffer_size:
+      if len(self.sendbuf) + len("{}.{}".format(self.prefix, stat)) > self.buffer_size:
         print("Sending {} bytes to {}".format(len(self.sendbuf), "{}:{}".format(self.host, self.port)))
         self.sock.send(self.sendbuf)
         self.sendbuf = ''
-      self.sendbuf += "{}\n".format(stat)
+      self.sendbuf += "{}.{}\n".format(self.prefix, stat)
 
   def disconnect(self):
     self.sock.close()
@@ -46,42 +46,35 @@ def parse_varnishstat():
   return json.loads(subprocess.check_output(['varnishstat', '-1', '-j']))
 
 
-def format_stat(title, metric, timestamp, prefix = None):
-  if prefix:
-    name = string.join([prefix, title],".") 
-  else:
-    name = title
-
-  return "{} {} {}".format(name, metric, timestamp)
-
-
-def report_status(prefix):
+def collect_metrics():
   stats  = parse_varnishstat()
   ts     = int(time.time())
 
   status = []
+  fmt = lambda x, y, z: "{} {} {}".format(x, stats[y]['value'], ts)
+
   # Cache
-  status.append(format(format_stat("cache.hit", stats['cache_hit']['value'], ts, prefix)))
-  status.append(format(format_stat("cache.hitpass", stats['cache_hitpass']['value'], ts, prefix)))
-  status.append(format(format_stat("cache.miss", stats['cache_miss']['value'], ts, prefix)))
+  status.append(fmt('cache.hit', 'cache_hit', ts))
+  status.append(fmt('cache.hitpass', 'cache_hitpass', ts))
+  status.append(fmt('cache.miss', 'cache_miss', ts))
 
   # Origin
-  status.append(format(format_stat("backend.conn", stats['backend_conn']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.unhealthy", stats['backend_unhealthy']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.busy", stats['backend_busy']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.fail", stats['backend_fail']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.reuse", stats['backend_reuse']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.toolate", stats['backend_toolate']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.recycle", stats['backend_recycle']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.retry", stats['backend_retry']['value'], ts, prefix)))
-  status.append(format(format_stat("backend.req", stats['backend_req']['value'], ts, prefix)))
+  status.append(fmt('backend.conn', 'backend_conn', ts))
+  status.append(fmt('backend.unhealthy', 'backend_unhealthy', ts))
+  status.append(fmt('backend.busy', 'backend_busy', ts))
+  status.append(fmt('backend.fail', 'backend_fail', ts))
+  status.append(fmt('backend.reuse', 'backend_reuse', ts))
+  status.append(fmt('backend.toolate', 'backend_toolate', ts))
+  status.append(fmt('backend.recycle', 'backend_recycle', ts))
+  status.append(fmt('backend.retry', 'backend_retry', ts))
+  status.append(fmt('backend.req', 'backend_req', ts))
 
   # Client
-  status.append(format(format_stat("client.conn", stats['client_conn']['value'], ts, prefix)))
-  status.append(format(format_stat("client.drop", stats['client_drop']['value'], ts, prefix)))
-  status.append(format(format_stat("client.req", stats['client_req']['value'], ts, prefix)))
-  status.append(format(format_stat("client.hdrbytes", stats['s_hdrbytes']['value'], ts, prefix)))
-  status.append(format(format_stat("client.bodybytes", stats['s_bodybytes']['value'], ts, prefix)))
+  status.append(fmt('client.conn', 'client_conn', ts))
+  status.append(fmt('client.drop', 'client_drop', ts))
+  status.append(fmt('client.req', 'client_req', ts))
+  status.append(fmt('client.hdrbytes', 's_hdrbytes', ts))
+  status.append(fmt('client.bodybytes', 's_bodybytes', ts))
 
   return status
 
@@ -101,7 +94,7 @@ def main():
 
   try:
     while True:
-      c.send_metrics(report_status(args.prefix))
+      c.send_metrics(collect_metrics())
       time.sleep(10)
   except KeyboardInterrupt:
     c.disconnect();