From e9254fbc5a9ff6b2725c59dce9615b6487f05cbb Mon Sep 17 00:00:00 2001 From: John Jarvis Date: Mon, 29 Apr 2013 23:40:17 -0400 Subject: [PATCH] Adding module to de-register/register EC2 instances This module handles AWS EC2 ELB registration. * De-registration requires the instance id which can be looked up using the ec2_facts module. * Registration requires both the instance id and the elbs that the instance belongs to. De-registration will return an ec2_elb fact that can be used for registration in post_tasks. --- library/cloud/ec2_elb | 190 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 190 insertions(+) create mode 100644 library/cloud/ec2_elb diff --git a/library/cloud/ec2_elb b/library/cloud/ec2_elb new file mode 100644 index 00000000000..7c1c7d870b0 --- /dev/null +++ b/library/cloud/ec2_elb @@ -0,0 +1,190 @@ +#!/usr/bin/python +# This file is part of Ansible +# +# Ansible is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. +# +# Ansible is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with Ansible. If not, see . + +DOCUMENTATION = """ +--- +module: ec2_elb +short_description: Registers and Deregisters instances from EC2 ELB(s) +description: + - This module deregisters or registers an AWS EC2 instance from the ELB(s) + that it belongs to. + Returns fact "elb_ec2" which is a list of elbs attached the instance + if deregister is called. +version_added: "1.2" +requirements: [ "boto" ] +author: John Jarvis +options: + action: + description: + - register or deregister the instance + required: true + + instance_id: + description: + - EC2 Instance ID + + elb_names: + description: + - List of ELB names, required for registration + required: false + default: None + ec2_secret_key: + description: + - AWS Secret API key + required: false + default: None + ec2_access_key: + description: + - AWS Access API key + required: false + default: None + +""" + +EXAMPLES = """ +# basic pre_task and post_task example +pre_tasks: + - name: Gathering ec2 facts + ec2_facts: + - name: Instance De-register + local_action: ec2_elb + args: + instance_id: "{{ ansible_ec2_instance_id }}" + action: 'deregister' +roles: + - myrole +post_tasks: + - name: Instance Register + local_action: ec2_elb + args: + instance_id: "{{ ansible_ec2_instance_id }}" + elb_names: "{{ ec2_elbs }}" + action: 'register' +""" + +import time +import sys +import os + +try: + import boto +except ImportError: + print "failed=True msg='boto required for this module'" + sys.exit(1) + + +class ElbManager: + """Handles EC2 instance ELB registration and deregistration""" + + def __init__(self, module, instance_id=None, elb_names=None, + ec2_access_key=None, ec2_secret_key=None): + self.ec2_access_key = ec2_access_key + self.ec2_secret_key = ec2_secret_key + self.module = module + self.instance_id = instance_id + self.lbs = self._get_instance_lbs(elb_names) + + def deregister(self): + """Deregister the instance from all ELBs and wait for the ELB + to report it out-of-service""" + + for lb in self.lbs: + lb.deregister_instances([self.instance_id]) + self._await_elb_instance_state(lb, 'OutOfService') + + def register(self): + """Register the instance for all ELBs and wait for the ELB + to report the instance in-service""" + + for lb in self.lbs: + lb.register_instances([self.instance_id]) + self._await_elb_instance_state(lb, 'InService') + + def _await_elb_instance_state(self, lb, awaited_state): + """Wait for an ELB to change state + lb: load balancer + awaited_state : state to poll for (string)""" + + while True: + state = lb.get_instance_health([self.instance_id])[0].state + if state == awaited_state: + break + else: + time.sleep(1) + + def _get_instance_lbs(self, elb_names=None): + """Returns a list of ELBs attached to self.instance_id""" + + try: + elb = boto.connect_elb(self.ec2_access_key, self.ec2_secret_key) + except boto.exception.NoAuthHandlerFound, e: + self.module.fail_json(msg=str(e)) + elbs = elb.get_all_load_balancers() + + if elb_names: + lbs = sorted(lb for lb in elbs if lb.name in elb_names) + else: + lbs = [] + for lb in elbs: + for info in lb.instances: + if self.instance_id == info.id: + lbs.append(lb) + return lbs + + +def main(): + + module = AnsibleModule( + argument_spec=dict( + action={'required': True, + 'choices': ['register', 'deregister']}, + instance_id={'required': True}, + elb_names={'default': None, 'required': False}, + ec2_secret_key={'default': None, 'aliases': ['EC2_SECRET_KEY']}, + ec2_access_key={'default': None, 'aliases': ['EC2_ACCESS_KEY']} + ) + ) + + ec2_secret_key = module.params['ec2_secret_key'] + ec2_access_key = module.params['ec2_access_key'] + elb_names = module.params['elb_names'] + + if module.params['action'] == 'register' and 'elb_names' not in module.params: + module.fail_json(msg="ELBs are required for registration") + + if not ec2_secret_key and 'EC2_SECRET_KEY' in os.environ: + ec2_secret_key = os.environ['EC2_SECRET_KEY'] + if not ec2_access_key and 'EC2_ACCESS_KEY' in os.environ: + ec2_access_key = os.environ['EC2_ACCESS_KEY'] + + instance_id = module.params['instance_id'] + elb_man = ElbManager(module, instance_id, elb_names, ec2_access_key, + ec2_secret_key) + + if module.params['action'] == 'register': + elb_man.register() + elif module.params['action'] == 'deregister': + elb_man.deregister() + + ansible_facts = {'ec2_elbs': [lb.name for lb in elb_man.lbs]} + ec2_facts_result = dict(changed=False, ansible_facts=ansible_facts) + + module.exit_json(**ec2_facts_result) + +# this is magic, see lib/ansible/module_common.py +#<> + +main()