Synnefo

#!/usr/bin/env python

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# -*- coding: utf-8 -*-

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"""Ganeti hooks for Synnefo

These are the individual Ganeti hooks for Synnefo.

"""

import sys

import os

import subprocess

import json

import socket

import logging

from time import time

from synnefo import settings

from synnefo.lib.amqp import AMQPClient

from synnefo.lib.utils import split_time

def mac2eui64(mac, prefixstr):

    process = subprocess.Popen(["mac2eui64", mac, prefixstr],

                                stdout=subprocess.PIPE)

    return process.stdout.read().rstrip()

def ganeti_net_status(logger, environ):

    """Produce notifications of type 'Ganeti-net-status'

    Process all GANETI_INSTANCE_NICx_y environment variables,

    where x is the NIC index, starting at 0,

    and y is one of "MAC", "IP", "BRIDGE".

    The result is returned as a single notification message

    of type 'ganeti-net-status', detailing the NIC configuration

    of a Ganeti instance.

    """

    nics = {}

    key_to_attr = {'IP': 'ip',

                   'MAC': 'mac',

                   'BRIDGE': 'link',

                   'NETWORK': 'network'}

    for env in environ.keys():

        if env.startswith("GANETI_INSTANCE_NIC"):

            s = env.replace("GANETI_INSTANCE_NIC", "").split('_', 1)

            if len(s) == 2 and s[0].isdigit() and\

               s[1] in ('MAC', 'IP', 'BRIDGE', 'NETWORK'):

                index = int(s[0])

                key = key_to_attr[s[1]]

                if index in nics:

                    nics[index][key] = environ[env]

                else:

                    nics[index] = {key: environ[env]}

                # IPv6 support:

                #

                # The IPv6 is derived using an EUI64 scheme.

                if key == 'mac':

                    subnet6 = environ.get("GANETI_INSTANCE_NIC" + s[0] +

                                          "_NETWORK_SUBNET6", None)

                    if subnet6:

                        nics[index]['ipv6'] = mac2eui64(nics[index]['mac'],

                                                        subnet6)

    # Amend notification with firewall settings

    tags = environ.get('GANETI_INSTANCE_TAGS', '')

    for tag in tags.split(' '):

        t = tag.split(':')

        if t[0:2] == ['synnefo', 'network']:

            if len(t) != 4:

                logger.error("Malformed synnefo tag %s", tag)

                continue

            try:

                index = int(t[2])

                nics[index]['firewall'] = t[3]

            except ValueError:

                logger.error("Malformed synnefo tag %s", tag)

            except KeyError:

                logger.error("Found tag %s for non-existent NIC %d",

                             tag, index)

    # Verify our findings are consistent with the Ganeti environment

    indexes = list(nics.keys())

    ganeti_nic_count = int(environ['GANETI_INSTANCE_NIC_COUNT'])

    if len(indexes) != ganeti_nic_count:

        logger.error("I have %d NICs, Ganeti says number of NICs is %d",

            len(indexes), ganeti_nic_count)

        raise Exception("Inconsistent number of NICs in Ganeti environment")

    if indexes != range(0, len(indexes)):

        logger.error("Ganeti NIC indexes are not consecutive starting at zero.");

        logger.error("NIC indexes are: %s. Environment is: %s", indexes, environ)

        raise Exception("Unexpected inconsistency in the Ganeti environment")

    # Construct the notification

    instance = environ['GANETI_INSTANCE_NAME']

    nics_list = []

    for i in indexes:

        nics_list.append(nics[i])

    msg = {

        "event_time": split_time(time()),

        "type": "ganeti-net-status",

        "instance": instance,

        "nics": nics_list

    }

    return msg

class GanetiHook():

    def __init__(self, logger, environ, instance, prefix):

        self.logger = logger

        self.environ = environ

        self.instance = instance

        self.prefix = prefix

        # Retry up to two times(per host) to open a channel to RabbitMQ.

        # The hook needs to abort if this count is exceeded, because it

        # runs synchronously with VM creation inside Ganeti, and may only

        # run for a finite amount of time.

        # FIXME: We need a reconciliation mechanism between the DB and

        #        Ganeti, for cases exactly like this.

        self.client = AMQPClient(hosts=settings.AMQP_HOSTS,

                                 max_retries = 2 * len(settings.AMQP_HOSTS))

        self.client.connect()

    def on_master(self):

        """Return True if running on the Ganeti master"""

        return socket.getfqdn() == self.environ['GANETI_MASTER']

    def publish_msgs(self, msgs):

        for (msgtype, msg) in msgs:

            routekey = "ganeti.%s.event.%s" % (self.prefix, msgtype)

            self.logger.debug("Pushing message to RabbitMQ: %s (key = %s)",

                              json.dumps(msg), routekey)

            msg = json.dumps(msg)

            self.client.basic_publish(exchange=settings.EXCHANGE_GANETI,

                                      routing_key=routekey,

                                      body=msg)

        self.client.close()

class PostStartHook(GanetiHook):

    """Post-instance-startup Ganeti Hook.

    Produce notifications to the rest of the Synnefo

    infrastructure in the post-instance-start phase of Ganeti.

    Currently, this list only contains a single message,

    detailing the net configuration of an instance.

    This hook only runs on the Ganeti master.

    """

    def run(self):

        if self.on_master():

            notifs = []

            notifs.append(("net", ganeti_net_status(self.logger, self.environ)))

            self.publish_msgs(notifs)

        return 0

class PostStopHook(GanetiHook):

    def run(self):

        return 0

def main():

    logging.basicConfig(level=logging.DEBUG)

    logger = logging.getLogger("synnefo.ganeti")

    try:

        instance = os.environ['GANETI_INSTANCE_NAME']

        op = os.environ['GANETI_HOOKS_PATH']

        phase = os.environ['GANETI_HOOKS_PHASE']

    except KeyError:

        raise Exception("Environment missing one of: " \

            "GANETI_INSTANCE_NAME, GANETI_HOOKS_PATH, GANETI_HOOKS_PHASE")

    prefix = instance.split('-')[0]

    # FIXME: The hooks should only run for Synnefo instances.

    # Uncomment the following lines for a shared Ganeti deployment.

    # Currently, the following code is commented out because multiple

    # backend prefixes are used in the same Ganeti installation during development.

    #if not instance.startswith(settings.BACKEND_PREFIX_ID):

    #    logger.warning("Ignoring non-Synnefo instance %s", instance)

    #    return 0

    hooks = {

        ("instance-add", "post"): PostStartHook,

        ("instance-start", "post"): PostStartHook,

        ("instance-reboot", "post"): PostStartHook,

        ("instance-stop", "post"): PostStopHook,

        ("instance-modify", "post"): PostStartHook

    }

    try:

        hook = hooks[(op, phase)](logger, os.environ, instance, prefix)

    except KeyError:

        raise Exception("No hook found for operation = '%s', phase = '%s'" % (op, phase))

    return hook.run()

if __name__ == "__main__":

    sys.exit(main())