ansible/library/cloud/ec2_elb
Bruce Pennypacker 8171b7ba48 Added optional region parameter. Fail if you specify an ELB that doesn't exist.
Boto blindly assumes the us-east-1 region if you don't hardcode a
region in it's config, so you could end up attempting to modify ELB's
in one region from a totally different region.  If a region isn't
specified then default to the region that the module is being run
within rather than the default us-east-1 region since it's a pretty
safe assumption that you intend to work on the ELB's within your
current region.

Also throw an error if a specified ELB instance doesn't exist.  The old
behavior would be to silently succeed with changed=false, so if you had
so much as a typo in the name of your ELB (or were in the wrong region
like my initial testing) you wouldn't get a clear indication that a
problem had occurred.
2013-08-01 16:50:01 -04:00

259 lines
8 KiB
Python

#!/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 <http://www.gnu.org/licenses/>.
DOCUMENTATION = """
---
module: ec2_elb
short_description: De-registers or registers instances from EC2 ELB(s)
description:
- This module de-registers or registers an AWS EC2 instance from the ELB(s)
that it belongs to.
- Returns fact "ec2_elbs" which is a list of elbs attached to the instance
if state=absent is passed as an argument.
- Will be marked changed when called only if there are ELBs found to operate on.
version_added: "1.2"
requirements: [ "boto", "urllib2" ]
author: John Jarvis
options:
state:
description:
- register or deregister the instance
required: true
instance_id:
description:
- EC2 Instance ID
required: true
ec2_elbs:
description:
- List of ELB names, required for registration. The ec2_elbs fact should be used if there was a previous de-register.
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
ec2_region:
description:
- AWS region of your load balancer. If not set then the region in which
this module is running will be used.
required: false
"""
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 }}"
state: 'absent'
roles:
- myrole
post_tasks:
- name: Instance Register
local_action: ec2_elb
args:
instance_id: "{{ ansible_ec2_instance_id }}"
ec2_elbs: "{{ ec2_elbs }}"
state: 'present'
"""
import time
import sys
import os
AWS_REGIONS = ['ap-northeast-1',
'ap-southeast-1',
'ap-southeast-2',
'eu-west-1',
'sa-east-1',
'us-east-1',
'us-west-1',
'us-west-2']
try:
import boto
import boto.ec2.elb
from boto.regioninfo import RegionInfo
except ImportError:
print "failed=True msg='boto required for this module'"
sys.exit(1)
try:
import urllib2
except ImportError:
print "failed=True msg='urllib2 required for this module'"
sys.exit(1)
class ElbManager:
"""Handles EC2 instance ELB registration and de-registration"""
def __init__(self, module, instance_id=None, ec2_elbs=None,
ec2_access_key=None, ec2_secret_key=None, ec2_region=None):
self.ec2_access_key = ec2_access_key
self.ec2_secret_key = ec2_secret_key
self.module = module
self.instance_id = instance_id
self.ec2_region = ec2_region
self.lbs = self._get_instance_lbs(ec2_elbs)
# if there are no ELBs to operate on
# there will be no changes made
if len(self.lbs) > 0:
self.changed = True
else:
self.changed = False
def deregister(self):
"""De-register 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 exists(self, lbtest):
""" Verify that the named ELB actually exists """
found = False
for lb in self.lbs:
if lb.name == lbtest:
found=True
break
return found
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, ec2_elbs=None):
"""Returns a list of ELBs attached to self.instance_id
ec2_elbs: an optional list of elb names that will be used
for elb lookup instead of returning what elbs
are attached to self.instance_id"""
try:
endpoint="elasticloadbalancing.%s.amazonaws.com" % self.ec2_region
connect_region = RegionInfo(name=self.ec2_region, endpoint=endpoint)
elb = boto.ec2.elb.ELBConnection(self.ec2_access_key, self.ec2_secret_key, region=connect_region)
except boto.exception.NoAuthHandlerFound, e:
self.module.fail_json(msg=str(e))
elbs = elb.get_all_load_balancers()
if ec2_elbs:
lbs = sorted(lb for lb in elbs if lb.name in ec2_elbs)
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(
state={'required': True,
'choices': ['present', 'absent']},
instance_id={'required': True},
ec2_elbs={'default': None, 'required': False},
ec2_secret_key={'default': None, 'aliases': ['EC2_SECRET_KEY']},
ec2_access_key={'default': None, 'aliases': ['EC2_ACCESS_KEY']},
ec2_region={'default': None, 'required': False, 'choices':AWS_REGIONS}
)
)
ec2_secret_key = module.params['ec2_secret_key']
ec2_access_key = module.params['ec2_access_key']
ec2_elbs = module.params['ec2_elbs']
ec2_region = module.params['ec2_region']
if module.params['state'] == 'present' and 'ec2_elbs' 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']
if not ec2_region and 'EC2_REGION' in os.environ:
ec2_region = os.environ['EC2_REGION']
if not ec2_region:
response = urllib2.urlopen('http://169.254.169.254/latest/meta-data/placement/availability-zone')
az = response.read()
for r in AWS_REGIONS:
if az.startswith(r):
ec2_region = r
break
if not ec2_region:
module.fail_json(msg = str("ec2_region not specified and unable to determine region from AWS."))
instance_id = module.params['instance_id']
elb_man = ElbManager(module, instance_id, ec2_elbs, ec2_access_key,
ec2_secret_key, ec2_region=ec2_region)
for elb in [ ec2_elbs ]:
if not elb_man.exists(elb):
str="ELB %s does not exist" % elb
module.fail_json(msg=str)
if module.params['state'] == 'present':
elb_man.register()
elif module.params['state'] == 'absent':
elb_man.deregister()
ansible_facts = {'ec2_elbs': [lb.name for lb in elb_man.lbs]}
ec2_facts_result = dict(changed=elb_man.changed, ansible_facts=ansible_facts)
module.exit_json(**ec2_facts_result)
# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
main()