mirror of https://github.com/zulip/zulip.git
151 lines
5.7 KiB
Python
Executable File
151 lines
5.7 KiB
Python
Executable File
#!/usr/bin/env python2.7
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# -*- coding: utf-8 -*-
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#
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# Copyright © 2013 Zulip, Inc.
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#
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# Permission is hereby granted, free of charge, to any person obtaining a copy
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# of this software and associated documentation files (the "Software"), to deal
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# in the Software without restriction, including without limitation the rights
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# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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# copies of the Software, and to permit persons to whom the Software is
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# furnished to do so, subject to the following conditions:
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#
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# The above copyright notice and this permission notice shall be included in
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# all copies or substantial portions of the Software.
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#
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# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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# THE SOFTWARE.
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# Original author: Luke Faraone
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'''Configure a host for EC2-VPC dynamically assigned network interfaces
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Amazon VPC gives us a good deal of flexibility compared to classic EC2.
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However there are limitations; you can assign multiple IPs to a host
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yet only the first IP per interface will be DHCP assigned, and you are
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limited in the total number of interfaces you have, so doing one-IP-per-
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interface is also untenable.
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This script grabs the metadata provided by AWS and uses it to correctly
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configure all available network interfaces.
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It is suitable to be hooked in to system boot and network
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reconfiguration scripts.
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Note that it currently does not handle the deconfiguration of
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interfaces.
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'''
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from __future__ import absolute_import
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import sys
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import logging
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import logging.handlers
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import subprocess
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import boto.utils
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import netifaces
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if False:
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# See https://zulip.readthedocs.io/en/latest/testing/mypy.html#mypy-in-production-scripts
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from typing import Optional
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def address_of(device_id):
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# type: (int) -> Optional[str]
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try:
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return netifaces.ifaddresses("ens%i" % (device_id,))[netifaces.AF_INET][0]['addr']
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except KeyError:
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return None
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def guess_gateway(device_id):
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# type: (int) -> Optional[str]
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# This will not work if the default gateway isn't n.n.n.1.
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address = address_of(device_id)
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if address is None:
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return None
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gateway = address.split('.')
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gateway[3] = '1'
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return '.'.join(gateway)
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log = logging.getLogger('configure-cloud-interfaces')
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log.setLevel(logging.DEBUG)
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log.addHandler(logging.handlers.SysLogHandler(facility=logging.handlers.SysLogHandler.LOG_DAEMON))
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log.addHandler(logging.StreamHandler())
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log.info("Starting.")
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metadata = boto.utils.get_instance_metadata()
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if metadata is None:
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log.error("Could not get instance metadata!")
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sys.exit(1)
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macs = metadata["network"]["interfaces"]["macs"]
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ids = [int(macdata['device-number']) for macdata in macs.values()]
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ifaces = [iface for iface in netifaces.interfaces() if ":" not in iface and iface != "lo"]
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# Number of IDs should equal number of interfaces
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if len(ids) != len(ifaces):
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log.error("Metadata indicated %i interfaces but we have %i!" % (len(ids), len(ifaces)))
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sys.exit(1)
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for device in macs.values():
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# There's an annoying API inconsistency here:
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# If you have multiple IPs, local-ipv4s is a list.
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# If you only have one, local-ipv4s is a string.
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# Who knew?
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if isinstance(device['local-ipv4s'], str):
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# Only do dhcp, don't try to assign addresses
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to_configure = [device['local-ipv4s']]
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else:
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to_configure = list(device['local-ipv4s'])
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device_number = int(device['device-number'])
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if subprocess.check_output(["lsb_release", '-sc']).strip() == "xenial":
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# HACK: It appears on Xenial device_number in the data set is 0 but in reality it is 3
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device_number += 3
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address = address_of(device_number)
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if address is None:
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# If the device was not autoconfigured, do so now.
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log.info("Device ens%i not configured, starting dhcpd" % (device_number,))
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subprocess.check_call(['/sbin/dhcpcd', 'ens%i' % (device_number,)])
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dev_num = str(device_number)
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address = address_of(device_number)
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gateway = guess_gateway(device_number)
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assert(address is not None)
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assert(gateway is not None)
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# Horrible hack to route return packets on the correct interface
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# See http://unix.stackexchange.com/a/4421/933
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subprocess.check_call(
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['/sbin/ip', 'rule', 'add', 'fwmark', dev_num, 'table', dev_num])
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subprocess.check_call(
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['/sbin/ip', 'route', 'add', '0.0.0.0/0', 'table', dev_num, 'dev',
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'ens%i' % (device_number,), 'via', gateway])
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subprocess.check_call(
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['/sbin/iptables', '-t', 'mangle', '-A', 'OUTPUT', '-m', 'conntrack', '--ctorigdst',
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address, '-j', 'MARK', '--set-mark', dev_num])
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to_configure.remove(address)
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for (count, ip) in enumerate(to_configure):
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# Configure the IP via a virtual interface
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device = "ens%i:%i" % (device_number, count)
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log.info("Configuring %s with IP %s" % (device, ip))
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subprocess.check_call(['/sbin/ifconfig', device, ip])
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subprocess.check_call(
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['/sbin/iptables', '-t', 'mangle', '-A', 'OUTPUT', '-m', 'conntrack', '--ctorigdst',
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ip, '-j', 'MARK', '--set-mark', str(device_number)])
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for throwaway in range(2):
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# Don't freak out if this doens't work.
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subprocess.call(
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['/sbin/ip', 'route', 'del', '10.0.0.0/8'])
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log.info("Finished.")
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