server: add --stats-file= scaffolding

no actual stats yet

src/wormhole/server/cli.py

@@ -48,8 +48,13 @@ def server(ctx):
     "--signal-error", is_flag=True,
     help="force all clients to fail with a message",
 )
+@click.option(
+    "--stats-file", default=None, type=type(u""), metavar="stats.json",
+    help="periodically write stats to a file for monitoring tools like Munin",
+)
 @click.pass_obj
-def start(cfg, signal_error, no_daemon, blur_usage, advertise_version, transit, rendezvous):
+def start(cfg, signal_error, no_daemon, blur_usage, advertise_version,
+          transit, rendezvous, stats_file):
     """
     Start a relay server
     """
@@ -60,6 +65,7 @@ def start(cfg, signal_error, no_daemon, blur_usage, advertise_version, transit,
     cfg.transit = str(transit)
     cfg.rendezvous = str(rendezvous)
     cfg.signal_error = signal_error
+    cfg.stats_file = stats_file
 
     start_server(cfg)
 
@@ -92,8 +98,13 @@ def start(cfg, signal_error, no_daemon, blur_usage, advertise_version, transit,
     "--signal-error", is_flag=True,
     help="force all clients to fail with a message",
 )
+@click.option(
+    "--stats-file", default=None, type=type(u""), metavar="stats.json",
+    help="periodically write stats to a file for monitoring tools like Munin",
+)
 @click.pass_obj
-def restart(cfg, signal_error, no_daemon, blur_usage, advertise_version, transit, rendezvous):
+def restart(cfg, signal_error, no_daemon, blur_usage, advertise_version,
+            transit, rendezvous, stats_file):
     """
     Re-start a relay server
     """
@@ -104,6 +115,7 @@ def restart(cfg, signal_error, no_daemon, blur_usage, advertise_version, transit
     cfg.transit = str(transit)
     cfg.rendezvous = str(rendezvous)
     cfg.signal_error = signal_error
+    cfg.stats_file = stats_file
 
     restart_server(cfg)
 

src/wormhole/server/cmd_server.py

@@ -15,6 +15,7 @@ class MyPlugin:
                            self.args.advertise_version,
                            "relay.sqlite", self.args.blur_usage,
                            signal_error=self.args.signal_error,
+                           stats_file=self.args.stats_file,
                            )
 
 class MyTwistdConfig(twistd.ServerOptions):

src/wormhole/server/rendezvous.py

@@ -1,5 +1,5 @@
 from __future__ import print_function, unicode_literals
-import os, time, random, base64
+import os, time, random, base64, json
 from collections import namedtuple
 from twisted.python import log
 from twisted.application import service, internet
@@ -478,15 +478,16 @@ class AppNamespace:
             channel._shutdown()
 
 class Rendezvous(service.MultiService):
-    def __init__(self, db, welcome, blur_usage):
+    def __init__(self, db, welcome, blur_usage, stats_file=None):
         service.MultiService.__init__(self)
         self._db = db
         self._welcome = welcome
         self._blur_usage = blur_usage
+        self._stats_file = stats_file
         log_requests = blur_usage is None
         self._log_requests = log_requests
         self._apps = {}
-        t = internet.TimerService(EXPIRATION_CHECK_PERIOD, self.prune_all_apps)
+        t = internet.TimerService(EXPIRATION_CHECK_PERIOD, self.timer)
         t.setServiceParent(self)
 
     def get_welcome(self):
@@ -517,6 +518,10 @@ class Rendezvous(service.MultiService):
             apps.add(row["app_id"])
         return apps
 
+    def timer(self):
+        self.prune_all_apps()
+        self.dump_stats(now=time.time(), validity=EXPIRATION_CHECK_PERIOD+60)
+
     def prune_all_apps(self, now=None, old=None):
         # As with AppNamespace.prune_old_mailboxes, we log for now.
         log.msg("beginning app prune")
@@ -528,6 +533,20 @@ class Rendezvous(service.MultiService):
             app.prune(now, old)
         log.msg("app prune ends, %d apps" % len(self._apps))
 
+    def dump_stats(self, now, validity):
+        if not self._stats_file:
+            return
+        tmpfn = self._stats_file + ".tmp"
+
+        data = {}
+        data["created"] = now
+        data["valid_until"] = now + validity
+
+        with open(tmpfn, "wb") as f:
+            json.dump(data, f, indent=1)
+            f.write("\n")
+        os.rename(tmpfn, self._stats_file)
+
     def stopService(self):
         # This forcibly boots any clients that are still connected, which
         # helps with unit tests that use threads for both clients. One client

src/wormhole/server/server.py

@@ -28,7 +28,7 @@ class PrivacyEnhancedSite(server.Site):
 class RelayServer(service.MultiService):
     def __init__(self, rendezvous_web_port, transit_port,
                  advertise_version, db_url=":memory:", blur_usage=None,
-                 signal_error=None):
+                 signal_error=None, stats_file=None):
         service.MultiService.__init__(self)
         self._blur_usage = blur_usage
 
@@ -52,7 +52,7 @@ class RelayServer(service.MultiService):
         if signal_error:
             welcome["error"] = signal_error
 
-        rendezvous = Rendezvous(db, welcome, blur_usage)
+        rendezvous = Rendezvous(db, welcome, blur_usage, stats_file)
         rendezvous.setServiceParent(self) # for the pruning timer
 
         root = Root()