Files
reddit/scripts/write_live_config
Neil Williams f501106d9c zookeeper: gzip live config payload.
This takes our current config payload from 4700 bytes to 1700. The goal
is to reduce zookeeper network load during config changes as well as app
restarts during deploys.
2015-03-02 10:41:07 -08:00

146 lines
5.0 KiB
Python
Executable File

#!/usr/bin/env python
# The contents of this file are subject to the Common Public Attribution
# License Version 1.0. (the "License"); you may not use this file except in
# compliance with the License. You may obtain a copy of the License at
# http://code.reddit.com/LICENSE. The License is based on the Mozilla Public
# License Version 1.1, but Sections 14 and 15 have been added to cover use of
# software over a computer network and provide for limited attribution for the
# Original Developer. In addition, Exhibit A has been modified to be consistent
# with Exhibit B.
#
# Software distributed under the License is distributed on an "AS IS" basis,
# WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for
# the specific language governing rights and limitations under the License.
#
# The Original Code is reddit.
#
# The Original Developer is the Initial Developer. The Initial Developer of
# the Original Code is reddit Inc.
#
# All portions of the code written by reddit are Copyright (c) 2006-2015 reddit
# Inc. All Rights Reserved.
###############################################################################
"""Read config from an INI file and put it in ZooKeeper for instant use."""
import os
import sys
import json
import getpass
import ConfigParser
import zlib
import kazoo.client
from kazoo.security import make_acl, make_digest_acl
from kazoo.exceptions import NoAuthException
from r2.lib.zookeeper import connect_to_zookeeper
from r2.lib.app_globals import extract_live_config, LIVE_CONFIG_NODE
from r2.lib.configparse import ConfigValue
from r2.lib.plugin import PluginLoader
from r2.lib.utils import parse_ini_file
USERNAME = "live-config"
def write_config_to_zookeeper(node, username, password, config, live_config):
"""Write given configuration to ZooKeeper with correct security etc."""
# read the zk configuration from the app's config
zk_hostlist = config.get("DEFAULT", "zookeeper_connection_string")
app_username = config.get("DEFAULT", "zookeeper_username")
app_password = config.get("DEFAULT", "zookeeper_password")
# connect to zk!
client = connect_to_zookeeper(zk_hostlist, (username, password))
# ensure that the path leading up to the config node exists. if it doesn't,
# create it with ACLs such that new stuff can be added below it, but no one
# but we can delete nodes.
parent_path = os.path.dirname(node)
client.ensure_path(parent_path, acl=[
# only we can delete children
make_digest_acl(username, password, delete=True),
# anyone authenticated can read/list children/create children
make_acl("auth", "", read=True, create=True),
])
# create or update the config node ensuring that only we can write to it.
json_data = json.dumps(live_config)
compressed_data = "gzip" + zlib.compress(json_data)
try:
client.create(node, compressed_data, acl=[
make_digest_acl(username, password, read=True, write=True),
make_digest_acl(app_username, app_password, read=True),
])
except kazoo.exceptions.NodeExistsException:
client.set(node, compressed_data)
def confirm_config(live_config):
"""Display the parsed live config and confirm that we should continue."""
max_key_length = max(len(k) for k in live_config.iterkeys())
print "Parsed Config:"
for key, value in sorted(live_config.iteritems(), key=lambda t: t[0]):
print " ", key.ljust(max_key_length), "=", repr(value)
answer = raw_input("Continue? [y|N] ")
return answer.lower() == "y"
def main():
"""Get and validate input from the user via CLI then write to ZK."""
progname = os.path.basename(sys.argv[0])
try:
ini_file_name = sys.argv[1]
except IndexError:
print >> sys.stderr, "USAGE: %s INI" % progname
return 1
try:
with open(ini_file_name) as ini_file:
config = parse_ini_file(ini_file)
except (IOError, ConfigParser.Error), e:
print >> sys.stderr, "%s: %s: %s" % (progname, ini_file_name, e)
return 1
try:
plugin_config = config.get("DEFAULT", "plugins")
plugin_names = ConfigValue.tuple(plugin_config)
plugins = PluginLoader(plugin_names=plugin_names)
live = extract_live_config(config, plugins)
except ValueError as e:
print >> sys.stderr, "%s: %s" % (progname, e)
return 1
else:
if not confirm_config(live):
print "Oh, well, never mind then. Bye :("
return 1
password = getpass.getpass("Password: ")
try:
write_config_to_zookeeper(LIVE_CONFIG_NODE,
USERNAME, password,
config, live)
except NoAuthException:
print >> sys.stderr, "%s: incorrect password" % progname
return 1
except Exception as e:
print >> sys.stderr, "%s: %s" % (progname, e)
return 1
print "Succesfully updated live config!"
return 0
if __name__ == "__main__":
sys.exit(main())