Split control and log to two separate tubs, remove control knobs.

This also removes the tahoe.cfg keys that would have configured the
control-port. And it deletes the logport.furl file before asking the Tub
to re-create it, because we're now using an ephemeral Tub (so we're not
persisting the private key, so the tubid will change each time).

closes ticket:2794

src/allmydata/node.py

@@ -85,6 +85,7 @@ class Node(service.MultiService):
         self.init_tempdir()
         self.create_tub()
         self.create_control_tub()
+        self.create_log_tub()
         self.logSource="Node"
 
         self.setup_logging()
@@ -167,16 +168,6 @@ class Node(service.MultiService):
             return "tcp:%d" % int(s)
         return s
 
-    def get_control_tub_port(self):
-        # return a descriptor string
-        cfg_tubport = self.get_config("node", "control_tub.port", "")
-        if cfg_tubport:
-            return self._convert_tub_port(cfg_tubport)
-
-        # XXX should really be: tcp:interface=127.0.0.1:1234
-        tubport = "tcp:%d" % iputil.allocate_tcp_port()
-        return tubport
-
     def get_tub_port(self):
         # return a descriptor string
         cfg_tubport = self.get_config("node", "tub.port", "")
@@ -191,16 +182,6 @@ class Node(service.MultiService):
         fileutil.write_atomically(self._portnumfile, tubport + "\n", mode="")
         return tubport
 
-    def get_control_tub_location(self, tubport):
-        location = self.get_config("node", "control_tub.location", "127.0.0.1")
-        # Replace the location "AUTO", if present, with the detected local
-        # addresses. Don't probe for local addresses unless necessary.
-        split_location = location.split(",")
-        new_locations = []
-        for loc in split_location:
-                new_locations.append(loc)
-        return ",".join(new_locations)
-
     def get_tub_location(self, tubport):
         location = self.get_config("node", "tub.location", "AUTO")
         # Replace the location "AUTO", if present, with the detected local
@@ -219,32 +200,13 @@ class Node(service.MultiService):
                 new_locations.append(loc)
         return ",".join(new_locations)
 
-    def create_control_tub(self):
-        certfile = os.path.join(self.basedir, "private", self.CERTFILE)
-        self.control_tub = Tub(certFile=certfile)
-        self.control_tub_options = {
-            "logLocalFailures": True,
-            "logRemoteFailures": True,
-            "expose-remote-exception-types": False,
-            }
-        for (name, value) in self.control_tub_options.items():
-            self.control_tub.setOption(name, value)
-        tubport = self.get_control_tub_port()
-        if tubport in ("0", "tcp:0"):
-            raise ValueError("tub.port cannot be 0: you must choose")
-        self.control_tub.listenOn(tubport)
-
-        location = self.get_control_tub_location(tubport)
-        self.control_tub.setLocation(location)
-        self.log("Control/logging Tub location set to %s" % (location,))
-
-        # the Tub is now ready for tub.registerReference()
-        self.control_tub.setServiceParent(self)
-
     def create_tub(self):
         certfile = os.path.join(self.basedir, "private", self.CERTFILE)
         self.tub = Tub(certFile=certfile)
         self.tub_options = {
+            "logLocalFailures": True,
+            "logRemoteFailures": True,
+            "expose-remote-exception-types": False,
             }
 
         # see #521 for a discussion of how to pick these timeout values.
@@ -273,6 +235,33 @@ class Node(service.MultiService):
         # the Tub is now ready for tub.registerReference()
         self.tub.setServiceParent(self)
 
+    def create_control_tub(self):
+        # the control port uses a localhost-only ephemeral Tub, with no
+        # control over the listening port or location
+        self.control_tub = Tub()
+        portnum = iputil.allocate_tcp_port()
+        port = "tcp:%d:interface=127.0.0.1" % portnum
+        location = "tcp:127.0.0.1:%d" % portnum
+        self.control_tub.listenOn(port)
+        self.control_tub.setLocation(location)
+        self.log("Control Tub location set to %s" % (location,))
+        self.control_tub.setServiceParent(self)
+
+    def create_log_tub(self):
+        # The logport uses a localhost-only ephemeral Tub, with no control
+        # over the listening port or location. This might change if we
+        # discover a compelling reason for it in the future (e.g. being able
+        # to use "flogtool tail" against a remote server), but for now I
+        # think we can live without it.
+        self.log_tub = Tub()
+        portnum = iputil.allocate_tcp_port()
+        port = "tcp:%d:interface=127.0.0.1" % portnum
+        location = "tcp:127.0.0.1:%d" % portnum
+        self.log_tub.listenOn(port)
+        self.log_tub.setLocation(location)
+        self.log("Log Tub location set to %s" % (location,))
+        self.log_tub.setServiceParent(self)
+
     def get_app_versions(self):
         # TODO: merge this with allmydata.get_package_versions
         return dict(app_versions.versions)
@@ -392,12 +381,14 @@ class Node(service.MultiService):
         # TODO: twisted >2.5.0 offers maxRotatedFiles=50
 
         lgfurl_file = os.path.join(self.basedir, "private", "logport.furl").encode(get_filesystem_encoding())
-        self.control_tub.setOption("logport-furlfile", lgfurl_file)
+        if os.path.exists(lgfurl_file):
+            os.remove(lgfurl_file)
+        self.log_tub.setOption("logport-furlfile", lgfurl_file)
         lgfurl = self.get_config("node", "log_gatherer.furl", "")
         if lgfurl:
             # this is in addition to the contents of log-gatherer-furlfile
-            self.control_tub.setOption("log-gatherer-furl", lgfurl)
+            self.log_tub.setOption("log-gatherer-furl", lgfurl)
-        self.control_tub.setOption("log-gatherer-furlfile",
+        self.log_tub.setOption("log-gatherer-furlfile",
                                os.path.join(self.basedir, "log_gatherer.furl"))
 
         incident_dir = os.path.join(self.basedir, "logs", "incidents")

topfiles/2794.change

@@ -0,0 +1,14 @@
+The little-used "control port" now uses a separate (ephemeral) Tub. This
+means the FURL changes each time the node is restarted, and it only listens
+on the loopback (127.0.0.1) interface, on a random port. As the control port
+is only used by some automated tests (check_memory, check_speed), this
+shouldn't affect anyone.
+
+The slightly-more-used "log port" now also uses a separate (ephemeral) Tub,
+with the same consequences. The lack of a stable (and externally-reachable)
+logport.furl means it is no longer possible to use `flogtool tail FURL`
+against a distant Tahoe server, however `flogtool tail
+.../nodedir/private/logport.furl` still works just fine (and is the more
+common use case anyways). We might bring back the ability to configure the
+port and location of the logport in the future, if there is sufficient
+demand, but for now it seems better to avoid the complexity.