tahoe-lafs/src/allmydata/scripts/stats_gatherer.py

104 lines
4.2 KiB
Python

from __future__ import print_function
import os
# Python 2 compatibility
from future.utils import PY2
if PY2:
from future.builtins import str # noqa: F401
from twisted.python import usage
from allmydata.scripts.common import NoDefaultBasedirOptions
from allmydata.scripts.create_node import write_tac
from allmydata.util.assertutil import precondition
from allmydata.util.encodingutil import listdir_unicode, quote_output
from allmydata.util import fileutil, iputil
class CreateStatsGathererOptions(NoDefaultBasedirOptions):
subcommand_name = "create-stats-gatherer"
optParameters = [
("hostname", None, None, "Hostname of this machine, used to build location"),
("location", None, None, "FURL connection hints, e.g. 'tcp:HOSTNAME:PORT'"),
("port", None, None, "listening endpoint, e.g. 'tcp:PORT'"),
]
def postOptions(self):
if self["hostname"] and (not self["location"]) and (not self["port"]):
pass
elif (not self["hostname"]) and self["location"] and self["port"]:
pass
else:
raise usage.UsageError("You must provide --hostname, or --location and --port.")
description = """
Create a "stats-gatherer" service, which is a standalone process that
collects and stores runtime statistics from many server nodes. This is a
tool for operations personnel to keep track of free disk space, server
load, and protocol activity, across a fleet of Tahoe storage servers.
The "stats-gatherer" listens on a TCP port and publishes a Foolscap FURL
by writing it into a file named "stats_gatherer.furl". You must copy this
FURL into the servers' tahoe.cfg, as the [client] stats_gatherer.furl=
entry. Those servers will then establish a connection to the
stats-gatherer and publish their statistics on a periodic basis. The
gatherer writes a summary JSON file out to disk after each update.
The stats-gatherer listens on a configurable port, and writes a
configurable hostname+port pair into the FURL that it publishes. There
are two configuration modes you can use.
* In the first, you provide --hostname=, and the service chooses its own
TCP port number. If the host is named "example.org" and you provide
--hostname=example.org, the node will pick a port number (e.g. 12345)
and use location="tcp:example.org:12345" and port="tcp:12345".
* In the second, you provide both --location= and --port=, and the
service will refrain from doing any allocation of its own. --location=
must be a Foolscap "FURL connection hint sequence", which is a
comma-separated list of "tcp:HOSTNAME:PORTNUM" strings. --port= must be
a Twisted server endpoint specification, which is generally
"tcp:PORTNUM". So, if your host is named "example.org" and you want to
use port 6789, you should provide --location=tcp:example.org:6789 and
--port=tcp:6789. You are responsible for making sure --location= and
--port= match each other.
"""
def create_stats_gatherer(config):
err = config.stderr
basedir = config['basedir']
# This should always be called with an absolute Unicode basedir.
precondition(isinstance(basedir, str), basedir)
if os.path.exists(basedir):
if listdir_unicode(basedir):
print("The base directory %s is not empty." % quote_output(basedir), file=err)
print("To avoid clobbering anything, I am going to quit now.", file=err)
print("Please use a different directory, or empty this one.", file=err)
return -1
# we're willing to use an empty directory
else:
os.mkdir(basedir)
write_tac(basedir, "stats-gatherer")
if config["hostname"]:
portnum = iputil.allocate_tcp_port()
location = "tcp:%s:%d" % (config["hostname"], portnum)
port = "tcp:%d" % portnum
else:
location = config["location"]
port = config["port"]
fileutil.write(os.path.join(basedir, "location"), location+"\n")
fileutil.write(os.path.join(basedir, "port"), port+"\n")
return 0
subCommands = [
["create-stats-gatherer", None, CreateStatsGathererOptions, "Create a stats-gatherer service."],
]
dispatch = {
"create-stats-gatherer": create_stats_gatherer,
}