#!/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. Since 1.9 you can set to None to detach.
    required: false
    default: null
  name:
    description:
      - volume Name tag if you wish to attach an existing volume (requires instance)
    required: false
    default: null
    version_added: "1.6"
  id:
    description:
      - volume id if you wish to attach an existing volume (requires instance) or remove an existing volume
    required: false
    default: null
    version_added: "1.6"
  volume_size:
    description:
      - size of volume (in GB) to create.
    required: false
    default: null
  volume_type:
    description:
      - Type of EBS volume; standard (magnetic), gp2 (SSD), io1 (Provisioned IOPS). "Standard" is the old EBS default
        and continues to remain the Ansible default for backwards compatibility.
    required: false
    default: standard
    version_added: "1.9"
  iops:
    description:
      - the provisioned IOPs you want to associate with this volume (integer).
    required: false
    default: 100
    version_added: "1.3"
  encrypted:
    description:
      - Enable encryption at rest for this volume.
    default: false
    version_added: "1.8"
  device_name:
    description:
      - device id to override device mapping. Assumes /dev/sdf for Linux/UNIX and /dev/xvdf for Windows. Can figure out a free device_name if device_name is a string with {}, {X}, {N} templates. Template syntax: {},{X} is a character in the [f-p] range, {N} is the character in the [1-6] range, according to EBS attachment notation docs here: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/device_naming.html .
    required: false
    default: null
  delete_on_termination:
    description:
      - When set to "yes", the volume will be deleted upon instance termination.
    required: false
    default: "no"
    choices: ["yes", "no"]
    version_added: "2.1"
  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: ['aws_zone', 'ec2_zone']
  snapshot:
    description:
      - snapshot ID on which to base the volume
    required: false
    default: null
    version_added: "1.5"
  validate_certs:
    description:
      - When set to "no", SSL certificates will not be validated for boto versions >= 2.6.0.
    required: false
    default: "yes"
    choices: ["yes", "no"]
    version_added: "1.5"
  state:
    description:
      - whether to ensure the volume is present or absent, or to list existing volumes (The C(list) option was added in version 1.8).
    required: false
    default: present
    choices: ['absent', 'present', 'list']
    version_added: "1.6"
author: "Lester Wade (@lwade)"
extends_documentation_fragment:
    - aws
    - ec2
'''

EXAMPLES = '''
# Simple attachment action
- ec2_vol:
    instance: XXXXXX
    volume_size: 5
    device_name: sdd

# Example using custom iops params
- ec2_vol:
    instance: XXXXXX
    volume_size: 5
    iops: 100
    device_name: sdd

# Example using snapshot id
- ec2_vol:
    instance: XXXXXX
    snapshot: "{{ snapshot }}"

# Playbook example combined with instance launch
- ec2:
    keypair: "{{ keypair }}"
    image: "{{ image }}"
    wait: yes
    count: 3
  register: ec2
- ec2_vol:
    instance: "{{ item.id }} "
    volume_size: 5
  with_items: ec2.instances
  register: ec2_vol

# Example: Launch an instance and then add a volume if not already attached
#   * Volume will be created with the given name if not already created.
#   * Nothing will happen if the volume is already attached.
#   * Requires Ansible 2.0

- ec2:
    keypair: "{{ keypair }}"
    image: "{{ image }}"
    zone: YYYYYY
    id: my_instance
    wait: yes
    count: 1
  register: ec2

- ec2_vol:
    instance: "{{ item.id }}"
    name: my_existing_volume_Name_tag
    device_name: /dev/xvdf
  with_items: ec2.instances
  register: ec2_vol

# Example: Launch an instance and then add a volume if not already attached
#   * Volume will be created with the given name if not already created.
#   * Volume will pick the first free /dev/xvd* slot according to template.
#   * Nothing will happen if the volume is already attached.
#   * Requires Ansible 2.0

- ec2_vol:
    instance: "{{ item.id }}"
    name: my_existing_volume_Name_tag
    device_name: /dev/xvd{}
  with_items: ec2.instances
  register: ec2_vol

# Remove a volume
- ec2_vol:
    id: vol-XXXXXXXX
    state: absen

# Detach a volume (since 1.9)
- ec2_vol:
    id: vol-XXXXXXXX
    instance: None

# List volumes for an instance
- ec2_vol:
    instance: i-XXXXXX
    state: list

# Create new volume using SSD storage
- ec2_vol:
    instance: XXXXXX
    volume_size: 50
    volume_type: gp2
    device_name: /dev/xvdf

# Attach an existing volume to instance. The volume will be deleted upon instance termination.
- ec2_vol:
    instance: XXXXXX
    id: XXXXXX
    device_name: /dev/sdf
    delete_on_termination: yes
'''

RETURN = '''
device:
    description: device name of attached volume
    returned: when success
    type: string
    sample: "/def/sdf"
volume_id:
    description: the id of volume
    returned: when success
    type: string
    sample: "vol-35b333d9"
volume_type:
    description: the volume type
    returned: when success
    type: string
    sample: "standard"
volume:
    description: a dictionary containing detailed attributes of the volume
    returned: when success
    type: string
    sample: {
        "attachment_set": {
            "attach_time": "2015-10-23T00:22:29.000Z",
            "deleteOnTermination": "false",
            "device": "/dev/sdf",
            "instance_id": "i-8356263c",
            "status": "attached"
        },
        "create_time": "2015-10-21T14:36:08.870Z",
        "encrypted": false,
        "id": "vol-35b333d9",
        "iops": null,
        "size": 1,
        "snapshot_id": "",
        "status": "in-use",
        "tags": {
            "env": "dev"
        },
        "type": "standard",
        "zone": "us-east-1b"
    }
'''

import time

from distutils.version import LooseVersion

try:
    import boto.ec2
    from boto.exception import BotoServerError
    from boto.ec2.blockdevicemapping import BlockDeviceType, BlockDeviceMapping
    HAS_BOTO = True
except ImportError:
    HAS_BOTO = False


def get_volume(module, ec2):
    name = module.params.get('name')
    id = module.params.get('id')
    zone = module.params.get('zone')
    filters = {}
    volume_ids = None

    # If no name or id supplied, just try volume creation based on module parameters
    if id is None and name is None:
        return None

    if zone:
        filters['availability_zone'] = zone
    if name:
        filters = {'tag:Name': name}
    if id:
        volume_ids = [id]
    try:
        vols = ec2.get_all_volumes(volume_ids=volume_ids, filters=filters)
    except boto.exception.BotoServerError, e:
        module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    if not vols:
        if id:
            msg = "Could not find the volume with id: %s" % id
            if name:
                msg += (" and name: %s" % name)
            module.fail_json(msg=msg)
        else:
            return None

    if len(vols) > 1:
        module.fail_json(msg="Found more than one volume in zone (if specified) with name: %s" % name)
    return vols[0]


def get_volumes(module, ec2):

    instance = module.params.get('instance')

    try:
        if not instance:
            vols = ec2.get_all_volumes()
        else:
            vols = ec2.get_all_volumes(filters={'attachment.instance-id': instance})
    except boto.exception.BotoServerError, e:
        module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))
    return vols


def delete_volume(module, ec2):
    volume_id = module.params['id']
    try:
        ec2.delete_volume(volume_id)
        module.exit_json(changed=True)
    except boto.exception.EC2ResponseError as ec2_error:
        if ec2_error.code == 'InvalidVolume.NotFound':
            module.exit_json(changed=False)
        module.fail_json(msg=ec2_error.message)


def boto_supports_volume_encryption():
    """
    Check if Boto library supports encryption of EBS volumes (added in 2.29.0)

    Returns:
        True if boto library has the named param as an argument on the request_spot_instances method, else False
    """
    return hasattr(boto, 'Version') and LooseVersion(boto.Version) >= LooseVersion('2.29.0')


def create_volume(module, ec2, zone):
    changed = False
    name = module.params.get('name')
    iops = module.params.get('iops')
    encrypted = module.params.get('encrypted')
    volume_size = module.params.get('volume_size')
    volume_type = module.params.get('volume_type')
    snapshot = module.params.get('snapshot')
    # If custom iops is defined we use volume_type "io1" rather than the default of "standard"
    if iops:
        volume_type = 'io1'

    volume = get_volume(module, ec2)
    if volume is None:
        try:
            if boto_supports_volume_encryption():
                volume = ec2.create_volume(volume_size, zone, snapshot, volume_type, iops, encrypted)
                changed = True
            else:
                volume = ec2.create_volume(volume_size, zone, snapshot, volume_type, iops)
                changed = True

            while volume.status != 'available':
                time.sleep(3)
                volume.update()

            if name:
                ec2.create_tags([volume.id], {"Name": name})
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    return volume, changed

# See: http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/device_naming.html
#      http://docs.aws.amazon.com/AWSEC2/latest/WindowsGuide/device_naming.html
#
DEVICE_LETTER_RANGE = tuple('fghijklmnop')
DEVICE_NUMBER_RANGE = tuple('123456')
ALL_DEVICE_NAME_TEMPLATES = ('{}', '{X}', '{N}')


def get_default_device_name_template(instance, ec2):
    """
    Try to infer whether to use Windows or linux device name pattern.
    Use instance.platform, password_data as indicators that instance
    is a Windows machine.
    """
    instance.update()

    if (instance.platform or '').lower() == 'windows':
        device_name = '/dev/xvd{}'
    elif ec2.get_password_data(instance.id):
        device_name = '/dev/xvd{}'
    else:
        device_name = '/dev/sd{}'
    return device_name

def is_device_name_templated(device_name):
    return any(t in device_name for t in ALL_DEVICE_NAME_TEMPLATES)

def get_next_device_name_from_template(device_name, module, ec2):
    """
    Look at already attached volumes and device_name template,
    and return the next free device name in alphabetical order
    """
    volumes = get_volumes(module, ec2)
    # python 2.6 str.format does not like unnamed items in templates
    device_name = device_name.replace('{}', '{X}')

    dev_choice_set = set(
        device_name.format(X=c, N=n)
        for c in DEVICE_LETTER_RANGE
        for n in DEVICE_NUMBER_RANGE
    )
    dev_busy_set = set(v.attach_data.device for v in volumes)
    dev_choices_left = sorted(dev_choice_set.difference(dev_busy_set))
    if 0 == len(dev_choices_left):
        module.fail_json(msg="Cant attach %s to %s: all /dev/ EBS devices busy"
                         % (volume.id, instance),
                         changed=True)
    device_name = dev_choices_left[0]
    return device_name


def attach_volume(module, ec2, volume, instance):

    device_name = module.params.get('device_name')
    delete_on_termination = module.params.get('delete_on_termination')
    changed = False

    # 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:
        try:
            device_name = get_default_device_name_template(instance, ec2)
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    if volume.attachment_state() is not None:
        adata = volume.attach_data
        if adata.instance_id != instance.id:
            module.fail_json(msg = "Volume %s is already attached to another instance: %s"
                             % (volume.id, adata.instance_id))
        else:
            # If device_name is a template to grab an available spot,
            # bring it into consistency with actual attachment data
            device_name = adata.device
            # Volume is already attached to right instance
            changed = modify_dot_attribute(module, ec2, instance, device_name)
    else:
        if is_device_name_templated(device_name):
            t = device_name
            device_name = get_next_device_name_from_template(t, module, ec2)
        try:
            volume.attach(instance.id, device_name)
            while volume.attachment_state() != 'attached':
                time.sleep(3)
                volume.update()
            changed = True
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

        modify_dot_attribute(module, ec2, instance, device_name)

    return volume, changed


def modify_dot_attribute(module, ec2, instance, device_name):
    """ Modify delete_on_termination attribute """

    delete_on_termination = module.params.get('delete_on_termination')
    changed = False

    try:
        instance.update()
        dot = instance.block_device_mapping[device_name].delete_on_termination
    except boto.exception.BotoServerError, e:
        module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    if delete_on_termination != dot:
        try:
            bdt = BlockDeviceType(delete_on_termination=delete_on_termination)
            bdm = BlockDeviceMapping()
            bdm[device_name] = bdt

            ec2.modify_instance_attribute(instance_id=instance.id, attribute='blockDeviceMapping', value=bdm)

            while instance.block_device_mapping[device_name].delete_on_termination != delete_on_termination:
                time.sleep(3)
                instance.update()
            changed = True
        except boto.exception.BotoServerError, e:
            module.fail_json(msg = "%s: %s" % (e.error_code, e.error_message))

    return changed


def detach_volume(module, ec2, volume):

    changed = False

    if volume.attachment_state() is not None:
        adata = volume.attach_data
        volume.detach()
        while volume.attachment_state() is not None:
            time.sleep(3)
            volume.update()
        changed = True

    return volume, changed


def get_volume_info(volume, state):

    # If we're just listing volumes then do nothing, else get the latest update for the volume
    if state != 'list':
        volume.update()

    volume_info = {}
    attachment = volume.attach_data

    volume_info = {
                    'create_time': volume.create_time,
                    'encrypted': volume.encrypted,
                    'id': volume.id,
                    'iops': volume.iops,
                    'size': volume.size,
                    'snapshot_id': volume.snapshot_id,
                    'status': volume.status,
                    'type': volume.type,
                    'zone': volume.zone,
                    'attachment_set': {
                        'attach_time': attachment.attach_time,
                        'device': attachment.device,
                        'instance_id': attachment.instance_id,
                        'status': attachment.status
                    },
                    'tags': volume.tags
                }
    if hasattr(attachment, 'deleteOnTermination'):
        volume_info['attachment_set']['deleteOnTermination'] = attachment.deleteOnTermination

    return volume_info


def main():
    argument_spec = ec2_argument_spec()
    argument_spec.update(dict(
            instance = dict(),
            id = dict(),
            name = dict(),
            volume_size = dict(),
            volume_type = dict(choices=['standard', 'gp2', 'io1'], default='standard'),
            iops = dict(),
            encrypted = dict(type='bool', default=False),
            device_name = dict(),
            delete_on_termination = dict(type='bool', default=False),
            zone = dict(aliases=['availability_zone', 'aws_zone', 'ec2_zone']),
            snapshot = dict(),
            state = dict(choices=['absent', 'present', 'list'], default='present')
        )
    )
    module = AnsibleModule(argument_spec=argument_spec)

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

    id = module.params.get('id')
    name = module.params.get('name')
    instance = module.params.get('instance')
    volume_size = module.params.get('volume_size')
    encrypted = module.params.get('encrypted')
    device_name = module.params.get('device_name')
    zone = module.params.get('zone')
    snapshot = module.params.get('snapshot')
    state = module.params.get('state')

    # Ensure we have the zone or can get the zone
    if instance is None and zone is None and state == 'present':
        module.fail_json(msg="You must specify either instance or zone")

    # Set volume detach flag
    if instance == 'None' or instance == '':
        instance = None
        detach_vol_flag = True
    else:
        detach_vol_flag = False

    # Set changed flag
    changed = False

    region, ec2_url, aws_connect_params = get_aws_connection_info(module)

    if region:
        try:
            ec2 = connect_to_aws(boto.ec2, region, **aws_connect_params)
        except (boto.exception.NoAuthHandlerFound, AnsibleAWSError), e:
            module.fail_json(msg=str(e))
    else:
        module.fail_json(msg="region must be specified")

    if state == 'list':
        returned_volumes = []
        vols = get_volumes(module, ec2)

        for v in vols:
            attachment = v.attach_data

            returned_volumes.append(get_volume_info(v, state))

        module.exit_json(changed=False, volumes=returned_volumes)

    if encrypted and not boto_supports_volume_encryption():
        module.fail_json(msg="You must use boto >= v2.29.0 to use encrypted volumes")

    # 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.
    inst = None
    if instance:
        try:
            reservation = ec2.get_all_instances(instance_ids=instance)
        except BotoServerError as e:
            module.fail_json(msg=e.message)
        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),
                                 volume_id=inst.block_device_mapping[device_name].volume_id,
                                 device=device_name,
                                 changed=False)

    # Delaying the checks until after the instance check allows us to get volume ids for existing volumes
    # without needing to pass an unused volume_size
    if not volume_size and not (id or name or snapshot):
        module.fail_json(msg="You must specify volume_size or identify an existing volume by id, name, or snapshot")

    # Cannot resize existing volumes, but can make a new volume of larger size
    # from snapshot
    if volume_size and id:
        module.fail_json(msg="Cannot specify volume_size together with id")

    if state == 'present':
        volume, changed = create_volume(module, ec2, zone)
        if detach_vol_flag:
            volume, changed = detach_volume(module, ec2, volume)
        elif inst is not None:
            volume, changed = attach_volume(module, ec2, volume, inst)

        # Add device, volume_id and volume_type parameters separately to maintain backward compatability
        volume_info = get_volume_info(volume, state)
        module.exit_json(changed=changed, volume=volume_info, device=volume_info['attachment_set']['device'], volume_id=volume_info['id'], volume_type=volume_info['type'])
    elif state == 'absent':
        delete_volume(module, ec2)

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

if __name__ == '__main__':
    main()
