ansible/cloud/amazon/ec2_eip.py

#!/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_eip
short_description: associate an EC2 elastic IP with an instance.
description:
    - This module associates AWS EC2 elastic IP addresses with instances
version_added: "1.4"
options:
  instance_id:
    description:
      - The EC2 instance id
    required: false
  network_interface_id:
    description:
      - The Elastic Network Interface (ENI) id
    required: false
    version_added: "2.0"
  public_ip:
    description:
      - The elastic IP address to associate with the instance.
      - If absent, allocate a new address
    required: false
  state:
    description:
      - If present, associate the IP with the instance.
      - If absent, disassociate the IP with the instance.
    required: false
    choices: ['present', 'absent']
    default: present
  region:
    description:
      - the EC2 region to use
    required: false
    default: null
    aliases: [ ec2_region ]
  in_vpc:
    description:
      - allocate an EIP inside a VPC or not
    required: false
    default: false
    version_added: "1.4"
  reuse_existing_ip_allowed:
    description:
      - Reuse an EIP that is not associated to an instance (when available), instead of allocating a new one.
    required: false
    default: false
    version_added: "1.6"
extends_documentation_fragment: aws
author: "Lorin Hochstein (@lorin) <lorin@nimbisservices.com>"
notes:
   - This module will return C(public_ip) on success, which will contain the
     public IP address associated with the instance.
   - There may be a delay between the time the Elastic IP is assigned and when
     the cloud instance is reachable via the new address. Use wait_for and
     pause to delay further playbook execution until the instance is reachable,
     if necessary.
'''

EXAMPLES = '''
- name: associate an elastic IP with an instance
  ec2_eip: instance_id=i-1212f003 ip=93.184.216.119
- name: associate an elastic IP with a device
  ec2_eip: network_interface_id=eni-c8ad70f3 ip=93.184.216.119
- name: disassociate an elastic IP from an instance
  ec2_eip: instance_id=i-1212f003 ip=93.184.216.119 state=absent
- name: disassociate an elastic IP with a device
  ec2_eip: network_interface_id=eni-c8ad70f3 ip=93.184.216.119 state=absent
- name: allocate a new elastic IP and associate it with an instance
  ec2_eip: instance_id=i-1212f003
- name: allocate a new elastic IP without associating it to anything
  action: ec2_eip
  register: eip
- name: output the IP
  debug: msg="Allocated IP is {{ eip.public_ip }}"
- name: another way of allocating an elastic IP without associating it to anything
  ec2_eip: state='present'
- name: provision new instances with ec2
  ec2: keypair=mykey instance_type=c1.medium image=emi-40603AD1 wait=yes'''
''' group=webserver count=3
  register: ec2
- name: associate new elastic IPs with each of the instances
  ec2_eip: "instance_id={{ item }}"
  with_items: ec2.instance_ids
- name: allocate a new elastic IP inside a VPC in us-west-2
  ec2_eip: region=us-west-2 in_vpc=yes
  register: eip
- name: output the IP
  debug: msg="Allocated IP inside a VPC is {{ eip.public_ip }}"
'''

try:
    import boto.ec2
    HAS_BOTO = True
except ImportError:
    HAS_BOTO = False


class EIPException(Exception):
    pass

def associate_ip_and_device(ec2, address, device_id, check_mode, isinstance=True):
    if address_is_associated_with_device(ec2, address, device_id, isinstance):
        return {'changed': False}

    # If we're in check mode, nothing else to do
    if not check_mode:
        if isinstance:
            if address.domain == "vpc":
                res = ec2.associate_address(device_id, allocation_id=address.allocation_id)
            else:
                res = ec2.associate_address(device_id, public_ip=address.public_ip)
        else:
            res = ec2.associate_address(network_interface_id=device_id, allocation_id=address.allocation_id)
        if not res:
            raise EIPException('association failed')

    return {'changed': True}


def disassociate_ip_and_device(ec2, address, device_id, check_mode, isinstance=True):
    if not address_is_associated_with_device(ec2, address, device_id, isinstance):
        return {'changed': False}

    # If we're in check mode, nothing else to do
    if not check_mode:
        if address.domain == 'vpc':
            res = ec2.disassociate_address(
                association_id=address.association_id)
        else:
            res = ec2.disassociate_address(public_ip=address.public_ip)

        if not res:
            raise EIPException('disassociation failed')

    return {'changed': True}


def _find_address_by_ip(ec2, public_ip):
    try:
        return ec2.get_all_addresses([public_ip])[0]
    except boto.exception.EC2ResponseError as e:
        if "Address '{}' not found.".format(public_ip) not in e.message:
            raise


def _find_address_by_device_id(ec2, device_id, isinstance=True):
    if isinstance:
        addresses = ec2.get_all_addresses(None, {'instance-id': device_id})
    else:
        addresses = ec2.get_all_addresses(None, {'network-interface-id': device_id})
    if addresses:
        return addresses[0]


def find_address(ec2, public_ip, device_id, isinstance=True):
    """ Find an existing Elastic IP address """
    if public_ip:
        return _find_address_by_ip(ec2, public_ip)
    elif device_id and isinstance:
        return _find_address_by_device_id(ec2, device_id)
    elif device_id:
        return _find_address_by_device_id(ec2, device_id, isinstance=False)


def address_is_associated_with_device(ec2, address, device_id, isinstance=True):
    """ Check if the elastic IP is currently associated with the device """
    address = ec2.get_all_addresses(address.public_ip)
    if address:
        if isinstance:
            return address and address[0].instance_id == device_id
        else:
            return address and address[0].network_interface_id == device_id
    return False


def allocate_address(ec2, domain, reuse_existing_ip_allowed):
    """ Allocate a new elastic IP address (when needed) and return it """
    if reuse_existing_ip_allowed:
        domain_filter = {'domain': domain or 'standard'}
        all_addresses = ec2.get_all_addresses(filters=domain_filter)

        unassociated_addresses = [a for a in all_addresses
                                  if not a.device_id]
        if unassociated_addresses:
            return unassociated_addresses[0]

    return ec2.allocate_address(domain=domain)


def release_address(ec2, address, check_mode):
    """ Release a previously allocated elastic IP address """

    # If we're in check mode, nothing else to do
    if not check_mode:
        if not address.release():
            EIPException('release failed')

    return {'changed': True}


def find_device(ec2, device_id, isinstance=True):
    """ Attempt to find the EC2 instance and return it """

    if isinstance:
        try:
            reservations = ec2.get_all_reservations(instance_ids=[device_id])
        except boto.exception.EC2ResponseError, e:
            module.fail_json(msg=str(e))

        if len(reservations) == 1:
            instances = reservations[0].instances
            if len(instances) == 1:
                return instances[0]
    else:
        try:
            interfaces = ec2.get_all_network_interfaces(network_interface_ids=[device_id])
        except boto.exception.EC2ResponseError, e:
            module.fail_json(msg=str(e))

        if len(interfaces) == 1:
            return interfaces[0]

    raise EIPException("could not find instance" + device_id)


def ensure_present(ec2, domain, address, device_id,
                   reuse_existing_ip_allowed, check_mode, isinstance=True):
    changed = False

    # Return the EIP object since we've been given a public IP
    if not address:
        if check_mode:
            return {'changed': True}

        address = allocate_address(ec2, domain, reuse_existing_ip_allowed)
        changed = True

    if device_id:
        # Allocate an IP for instance since no public_ip was provided
        if isinstance:
            instance = find_device(ec2, device_id)
            # Associate address object (provided or allocated) with instance
            assoc_result = associate_ip_and_device(ec2, address, device_id,
                                                 check_mode)
        else:
            instance = find_device(ec2, device_id, isinstance=False)
            # Associate address object (provided or allocated) with instance
            assoc_result = associate_ip_and_device(ec2, address, device_id,
                                                 check_mode, isinstance=False)

        if instance.vpc_id:
            domain = 'vpc'

        changed = changed or assoc_result['changed']

    return {'changed': changed, 'public_ip': address.public_ip}


def ensure_absent(ec2, domain, address, device_id, check_mode, isinstance=True):
    if not address:
        return {'changed': False}

    # disassociating address from instance
    if device_id:
        if isinstance:
            return disassociate_ip_and_device(ec2, address, device_id,
                                                check_mode)
        else:
            return disassociate_ip_and_device(ec2, address, device_id,
                                                check_mode, isinstance=False)
    # releasing address
    else:
        return release_address(ec2, address, check_mode)


def main():
    argument_spec = ec2_argument_spec()
    argument_spec.update(dict(
        instance_id=dict(required=False),
        network_interface_id=dict(required=False),
        public_ip=dict(required=False, aliases=['ip']),
        state=dict(required=False, default='present',
                   choices=['present', 'absent']),
        in_vpc=dict(required=False, type='bool', default=False),
        reuse_existing_ip_allowed=dict(required=False, type='bool',
                                       default=False),
        wait_timeout=dict(default=300),
    ))

    module = AnsibleModule(
        argument_spec=argument_spec,
        supports_check_mode=True
    )

    if not HAS_BOTO:
        module.fail_json(msg='boto required for this module')

    ec2 = ec2_connect(module)

    instance_id = module.params.get('instance_id')
    network_interface_id = module.params.get('network_interface_id')
    public_ip = module.params.get('public_ip')
    state = module.params.get('state')
    in_vpc = module.params.get('in_vpc')
    domain = 'vpc' if in_vpc else None
    reuse_existing_ip_allowed = module.params.get('reuse_existing_ip_allowed')

    try:
        if network_interface_id:
            address = find_address(ec2, public_ip, network_interface_id, isinstance=False)
        elif instance_id:
            address = find_address(ec2, public_ip, instance_id)
        else:
            address = False

        if state == 'present':
            if instance_id:
                result = ensure_present(ec2, domain, address, instance_id,
                                    reuse_existing_ip_allowed,
                                    module.check_mode)
            elif network_interface_id:
                result = ensure_present(ec2, domain, address, network_interface_id,
                                    reuse_existing_ip_allowed,
                                    module.check_mode, isinstance=False)
            else:
                address = allocate_address(ec2, domain, reuse_existing_ip_allowed)
                result = {'changed': True, 'public_ip': address.public_ip}
        else:
            if network_interface_id:
                result = ensure_absent(ec2, domain, address, network_interface_id, module.check_mode, isinstance=False)
            elif instance_id:
                result = ensure_absent(ec2, domain, address, instance_id, module.check_mode)
            else:
                address = find_address(ec2, public_ip, None)
                result = release_address(ec2, address, module.check_mode)

    except (boto.exception.EC2ResponseError, EIPException) as e:
        module.fail_json(msg=str(e))

    module.exit_json(**result)

# import module snippets
from ansible.module_utils.basic import *  # noqa
from ansible.module_utils.ec2 import *  # noqa

if __name__ == '__main__':
    main()