mirror of https://github.com/zulip/zulip.git
72 lines
2.5 KiB
Plaintext
72 lines
2.5 KiB
Plaintext
|
#!/usr/bin/python
|
||
|
|
# -*- coding: utf-8 -*-
|
||
|
|
'''Configure a host for EC2-VPC dynamically assigned network interfaces
|
||
|
|
|
||
|
|
Amazon VPC gives us a good deal of flexibility compared to classic EC2.
|
||
|
|
However there are limitations; you can assign multiple IPs to a host
|
||
|
|
yet only the first IP per interface will be DHCP assigned, and you are
|
||
|
|
limited in the total number of interfaces you have, so doing one-IP-per-
|
||
|
|
interface is also untenable.
|
||
|
|
|
||
|
|
This script grabs the metadata provided by AWS and uses it to correctly
|
||
|
|
configure all available network interfaces.
|
||
|
|
|
||
|
|
It is suitable to be hooked in to system boot and network
|
||
|
|
reconfiguration scripts.
|
||
|
|
|
||
|
|
Note that it currently does not handle the deconfiguration of
|
||
|
|
interfaces.
|
||
|
|
|
||
|
|
'''
|
||
|
|
|
||
|
|
import sys
|
||
|
|
import syslog
|
||
|
|
import subprocess
|
||
|
|
import re
|
||
|
|
|
||
|
|
import boto.utils
|
||
|
|
import netifaces
|
||
|
|
|
||
|
|
def address_of(device_id):
|
||
|
|
try:
|
||
|
|
return netifaces.ifaddresses("eth%i" % device_id)[netifaces.AF_INET][0]['addr']
|
||
|
|
except KeyError:
|
||
|
|
return None
|
||
|
|
|
||
|
|
syslog.openlog(logoption=syslog.LOG_PID)
|
||
|
|
syslog.syslog("ec2ify starting")
|
||
|
|
|
||
|
|
macs = boto.utils.get_instance_metadata()["network"]["interfaces"]["macs"]
|
||
|
|
ids = [int(macdata['device-number']) for macdata in macs.values()]
|
||
|
|
ifaces = [iface for iface in netifaces.interfaces() if ":" not in iface and iface != "lo"]
|
||
|
|
|
||
|
|
# Number of IDs should equal number of interfaces
|
||
|
|
if len(ids) != len(ifaces):
|
||
|
|
syslog.syslog(syslog.LOG_ERR, "Metadata indicated %i interfaces but we have %i!" % (len(ids), len(ifaces)))
|
||
|
|
sys.exit(1)
|
||
|
|
|
||
|
|
for device in macs.values():
|
||
|
|
# There's an annoying API inconsistency here:
|
||
|
|
# If you have multiple IPs, local-ipv4s is a list.
|
||
|
|
# If you only have one, local-ipv4s is a string.
|
||
|
|
# Who knew?
|
||
|
|
if type(device['local-ipv4s']) is str:
|
||
|
|
# Only do dhcp, don't try to assign addresses
|
||
|
|
to_configure = [device['local-ipv4s']]
|
||
|
|
else:
|
||
|
|
to_configure = list(device['local-ipv4s'])
|
||
|
|
device_number = int(device['device-number'])
|
||
|
|
|
||
|
|
if address_of(device_number) is None:
|
||
|
|
# If the device was not autoconfigured, do so now.
|
||
|
|
syslog.syslog(syslog.LOG_INFO, "Device eth%i not configured, starting dhcpd" % device_number)
|
||
|
|
subprocess.check_call(['/sbin/dhcpcd', 'eth%i' % device_number])
|
||
|
|
|
||
|
|
to_configure.remove(address_of(device_number))
|
||
|
|
|
||
|
|
for (count, ip) in enumerate(to_configure):
|
||
|
|
# Configure the IP via a virtual interface
|
||
|
|
device = "eth%i:%i" % (device_number, count)
|
||
|
|
syslog.syslog(syslog.LOG_INFO, "Configuring %s with IP %s" % (device, ip))
|
||
|
|
subprocess.check_call(['/sbin/ifconfig', device, ip])
|