#!/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_vol
short_description: create and attach a volume, return volume id and device map
description:
    - creates an EBS volume and optionally attaches it to an instance.  If both an instance ID and a device name is given and the instance has a device at the device name, then no volume is created and no attachment is made.  This module has a dependency on python-boto.
version_added: "1.1"
options:
  instance:
    description:
      - instance ID if you wish to attach the volume. 
    required: false
    default: null 
    aliases: []
  volume_size:
    description:
      - size of volume (in GB) to create.
    required: true
    default: null
    aliases: []
  device_name:
    description:
      - device id to override device mapping. Assumes /dev/sdf for Linux/UNIX and /dev/xvdf for Windows.
    required: false
    default: null
    aliases: []
  region:
    description:
      - region in which to create the volume
    required: false
    default: null
    aliases: []
  zone:
    description:
      - zone in which to create the volume, if unset uses the zone the instance is in (if set) 
    required: false
    default: null
    aliases: []
requirements: [ "boto" ]
author: Lester Wade
'''

EXAMPLES = '''
# Simple attachment action
- local_action: 
    module: ec2_vol 
    instance: XXXXXX 
    volume_size: 5 
    device_name: sdd
   
# Playbook example combined with instance launch 
- local_action: 
    module: ec2 
    keypair: $keypair 
    image: $image 
    wait: yes 
    count: 3
    register: ec2
- local_action: 
    module: ec2_vol 
    instance: ${item.id} 
    volume_size: 5
    with_items: ${ec2.instances}
    register: ec2_vol
'''

# Note: this module needs to be made idempotent. Possible solution is to use resource tags with the volumes.
# if state=present and it doesn't exist, create, tag and attach. 
# Check for state by looking for volume attachment with tag (and against block device mapping?).
# Would personally like to revisit this in May when Eucalyptus also has tagging support (3.3).

import sys
import time

try:
    import boto.ec2
except ImportError:
    print "failed=True msg='boto required for this module'"
    sys.exit(1)

def main():
    module = AnsibleModule(
        argument_spec = dict(
            instance = dict(),
            volume_size = dict(required=True),
            device_name = dict(),
            region = dict(),
            zone = dict(),
            ec2_url = dict(aliases=['EC2_URL']),
            ec2_secret_key = dict(aliases=['EC2_SECRET_KEY']),
            ec2_access_key = dict(aliases=['EC2_ACCESS_KEY']),
        )
    )

    instance = module.params.get('instance')
    volume_size = module.params.get('volume_size')
    device_name = module.params.get('device_name')
    region = module.params.get('region')
    zone = module.params.get('zone')
    ec2_url = module.params.get('ec2_url')
    ec2_secret_key = module.params.get('ec2_secret_key')
    ec2_access_key = module.params.get('ec2_access_key')

    # allow eucarc environment variables to be used if ansible vars aren't set
    if not ec2_url and 'EC2_URL' in os.environ:
        ec2_url = os.environ['EC2_URL']
    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 we have a region specified, connect to its endpoint.
    if region: 
        try:
            ec2 = boto.ec2.connect_to_region(region, aws_access_key_id=ec2_access_key, aws_secret_access_key=ec2_secret_key)
        except boto.exception.NoAuthHandlerFound, e:
            module.fail_json(msg = str(e))
    # Otherwise, no region so we fallback to the old connection method
    else: 
        try:
            if ec2_url: # if we have an URL set, connect to the specified endpoint 
                ec2 = boto.connect_ec2_endpoint(ec2_url, ec2_access_key, ec2_secret_key)
            else: # otherwise it's Amazon.
                ec2 = boto.connect_ec2(ec2_access_key, ec2_secret_key)
        except boto.exception.NoAuthHandlerFound, e:
            module.fail_json(msg = str(e))

    # Here we need to get the zone info for the instance. This covers situation where 
    # instance is specified but zone isn't.
    # Useful for playbooks chaining instance launch with volume create + attach and where the
    # zone doesn't matter to the user.

    if instance:
        reservation = ec2.get_all_instances(instance_ids=instance)
        inst = reservation[0].instances[0]
        zone = inst.placement

        # Check if there is a volume already mounted there.
        if device_name:
            if device_name in inst.block_device_mapping:
                module.exit_json(msg="Volume mapping for %s already exists on instance %s" % (device_name, instance),
                                 changed=False)

    # If no instance supplied, try volume creation based on module parameters.

    try:
        volume = ec2.create_volume(volume_size, zone)
        while volume.status != 'available':
            time.sleep(3)
            volume.update()
    except boto.exception.BotoServerError, e:
        module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    # Attach the created volume.

    if device_name and instance:
        try:
            attach = volume.attach(inst.id, device_name)
            while volume.attachment_state() != 'attached':
                time.sleep(3)
                volume.update()
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))           
   
    # If device_name isn't set, make a choice based on best practices here:
    # http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/block-device-mapping-concepts.html
    
    # In future this needs to be more dynamic but combining block device mapping best practices
    # (bounds for devices, as above) with instance.block_device_mapping data would be tricky. For me ;)

    # Use password data attribute to tell whether the instance is Windows or Linux

    if device_name is None and instance:
        try:
            if not ec2.get_password_data(inst.id):
                device_name = '/dev/sdf'
                attach = volume.attach(inst.id, device_name)
                while volume.attachment_state() != 'attached':
                    time.sleep(3)
                    volume.update()
            else:
                device_name = '/dev/xvdf'
                attach = volume.attach(inst.id, device_name)
                while volume.attachment_state() != 'attached':
                    time.sleep(3)
                    volume.update()
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    print json.dumps({
        "volume_id": volume.id,
        "device": device_name
    })
    sys.exit(0)

# this is magic, see lib/ansible/module_common.py
#<<INCLUDE_ANSIBLE_MODULE_COMMON>>

main()
