#!/usr/bin/python
#
# Copyright 2016 Red Hat | Ansible
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import absolute_import, division, print_function
__metaclass__ = type


ANSIBLE_METADATA = {'metadata_version': '1.1',
                    'status': ['preview'],
                    'supported_by': 'community'}


DOCUMENTATION = '''
module: docker_network
version_added: "2.2"
short_description: Manage Docker networks
description:
  - Create/remove Docker networks and connect containers to them.
  - Performs largely the same function as the "docker network" CLI subcommand.
options:
  name:
    description:
      - Name of the network to operate on.
    required: true
    aliases:
      - network_name

  connected:
    description:
      - List of container names or container IDs to connect to a network.
    aliases:
      - containers

  driver:
    description:
      - Specify the type of network. Docker provides bridge and overlay drivers, but 3rd party drivers can also be used.
    default: bridge

  driver_options:
    description:
      - Dictionary of network settings. Consult docker docs for valid options and values.

  force:
    description:
      - With state I(absent) forces disconnecting all containers from the
        network prior to deleting the network. With state I(present) will
        disconnect all containers, delete the network and re-create the
        network.  This option is required if you have changed the IPAM or
        driver options and want an existing network to be updated to use the
        new options.
    type: bool
    default: 'no'

  appends:
    description:
      - By default the connected list is canonical, meaning containers not on the list are removed from the network.
        Use C(appends) to leave existing containers connected.
    type: bool
    default: 'no'
    aliases:
      - incremental

  enable_ipv6:
    version_added: 2.8
    description:
      - Enable IPv6 networking.
    type: bool
    default: null
    required: false

  ipam_driver:
    description:
      - Specify an IPAM driver.

  ipam_options:
    description:
      - Dictionary of IPAM options.
      - Deprecated in 2.8, will be removed in 2.12. Use parameter C(ipam_config) instead. In Docker 1.10.0, IPAM
        options were introduced (see L(here,https://github.com/moby/moby/pull/17316)). This module parameter addresses
        the IPAM config not the newly introduced IPAM options.

  ipam_config:
    version_added: 2.8
    description:
      - List of IPAM config blocks. Consult
        L(Docker docs,https://docs.docker.com/compose/compose-file/compose-file-v2/#ipam) for valid options and values.
        Note that I(iprange) is spelled differently here (we use the notation from the Docker Python SDK).
    type: list
    default: null
    required: false
    suboptions:
      subnet:
        description:
          - IP subset in CIDR notation.
        type: str
      iprange:
        description:
          - IP address range in CIDR notation.
        type: str
      gateway:
        description:
          - IP gateway address.
        type: str
      aux_addresses:
        description:
          - Auxiliary IP addresses used by Network driver, as a mapping from hostname to IP.
        type: dict

  state:
    description:
      - I(absent) deletes the network. If a network has connected containers, it
        cannot be deleted. Use the C(force) option to disconnect all containers
        and delete the network.
      - I(present) creates the network, if it does not already exist with the
        specified parameters, and connects the list of containers provided via
        the connected parameter. Containers not on the list will be disconnected.
        An empty list will leave no containers connected to the network. Use the
        C(appends) option to leave existing containers connected. Use the C(force)
        options to force re-creation of the network.
    default: present
    choices:
      - absent
      - present

  internal:
    version_added: 2.8
    description:
      - Restrict external access to the network.
    type: bool
    default: null
    required: false

extends_documentation_fragment:
    - docker

author:
    - "Ben Keith (@keitwb)"
    - "Chris Houseknecht (@chouseknecht)"
    - "Dave Bendit (@DBendit)"

requirements:
    - "python >= 2.6"
    - "docker-py >= 1.10.0"
    - "Please note that the L(docker-py,https://pypi.org/project/docker-py/) Python
       module has been superseded by L(docker,https://pypi.org/project/docker/)
       (see L(here,https://github.com/docker/docker-py/issues/1310) for details).
       For Python 2.6, C(docker-py) must be used. Otherwise, it is recommended to
       install the C(docker) Python module. Note that both modules should I(not)
       be installed at the same time. Also note that when both modules are installed
       and one of them is uninstalled, the other might no longer function and a
       reinstall of it is required."
    - "The docker server >= 1.10.0"
'''

EXAMPLES = '''
- name: Create a network
  docker_network:
    name: network_one

- name: Remove all but selected list of containers
  docker_network:
    name: network_one
    connected:
      - container_a
      - container_b
      - container_c

- name: Remove a single container
  docker_network:
    name: network_one
    connected: "{{ fulllist|difference(['container_a']) }}"

- name: Add a container to a network, leaving existing containers connected
  docker_network:
    name: network_one
    connected:
      - container_a
    appends: yes

- name: Create a network with driver options
  docker_network:
    name: network_two
    driver_options:
      com.docker.network.bridge.name: net2

- name: Create a network with custom IPAM config
  docker_network:
    name: network_three
    ipam_config:
      - subnet: 172.3.27.0/24
        gateway: 172.3.27.2
        iprange: 172.3.27.0/26
        aux_addresses:
          host1: 172.3.27.3
          host2: 172.3.27.4

- name: Create a network with IPv6 IPAM config
  docker_network:
    name: network_ipv6_one
    enable_ipv6: yes
    ipam_config:
      - subnet: fdd1:ac8c:0557:7ce1::/64

- name: Create a network with IPv6 and custom IPv4 IPAM config
  docker_network:
    name: network_ipv6_two
    enable_ipv6: yes
    ipam_config:
      - subnet: 172.4.27.0/24
      - subnet: fdd1:ac8c:0557:7ce2::/64

- name: Delete a network, disconnecting all containers
  docker_network:
    name: network_one
    state: absent
    force: yes
'''

RETURN = '''
facts:
    description: Network inspection results for the affected network.
    returned: success
    type: dict
    sample: {}
'''

import re

from ansible.module_utils.docker_common import AnsibleDockerClient, DockerBaseClass, HAS_DOCKER_PY_2, HAS_DOCKER_PY_3

try:
    from docker import utils
    from docker.errors import NotFound
    if HAS_DOCKER_PY_2 or HAS_DOCKER_PY_3:
        from docker.types import IPAMPool, IPAMConfig
except Exception as dummy:
    # missing docker-py handled in ansible.module_utils.docker_common
    pass


class TaskParameters(DockerBaseClass):
    def __init__(self, client):
        super(TaskParameters, self).__init__()
        self.client = client

        self.network_name = None
        self.connected = None
        self.driver = None
        self.driver_options = None
        self.ipam_driver = None
        self.ipam_options = None
        self.ipam_config = None
        self.appends = None
        self.force = None
        self.internal = None
        self.debug = None
        self.enable_ipv6 = None

        for key, value in client.module.params.items():
            setattr(self, key, value)


def container_names_in_network(network):
    return [c['Name'] for c in network['Containers'].values()] if network['Containers'] else []


CIDR_IPV4 = re.compile(r'^([0-9]{1,3}\.){3}[0-9]{1,3}/([0-9]|[1-2][0-9]|3[0-2])$')
CIDR_IPV6 = re.compile(r'^[0-9a-fA-F:]+/([0-9]|[1-9][0-9]|1[0-2][0-9])$')


def get_ip_version(cidr):
    """Gets the IP version of a CIDR string

    :param cidr: Valid CIDR
    :type cidr: str
    :return: ``ipv4`` or ``ipv6``
    :rtype: str
    :raises ValueError: If ``cidr`` is not a valid CIDR
    """
    if CIDR_IPV4.match(cidr):
        return 'ipv4'
    elif CIDR_IPV6.match(cidr):
        return 'ipv6'
    raise ValueError('"{0}" is not a valid CIDR'.format(cidr))


def get_driver_options(driver_options):
    result = dict()
    if driver_options is not None:
        for k, v in driver_options.items():
            # Go doesn't like 'True' or 'False'
            if v is True:
                v = 'true'
            elif v is False:
                v = 'false'
            else:
                v = str(v)
            result[str(k)] = v
    return result


class DockerNetworkManager(object):

    def __init__(self, client):
        self.client = client
        self.parameters = TaskParameters(client)
        self.check_mode = self.client.check_mode
        self.results = {
            u'changed': False,
            u'actions': []
        }
        self.diff = self.client.module._diff

        self.existing_network = self.get_existing_network()

        if not self.parameters.connected and self.existing_network:
            self.parameters.connected = container_names_in_network(self.existing_network)

        if (self.parameters.ipam_options['subnet'] or self.parameters.ipam_options['iprange'] or
                self.parameters.ipam_options['gateway'] or self.parameters.ipam_options['aux_addresses']):
            self.parameters.ipam_config = [self.parameters.ipam_options]

        if self.parameters.driver_options:
            self.parameters.driver_options = get_driver_options(self.parameters.driver_options)

        state = self.parameters.state
        if state == 'present':
            self.present()
        elif state == 'absent':
            self.absent()

    def get_existing_network(self):
        try:
            return self.client.inspect_network(self.parameters.network_name)
        except NotFound:
            return None

    def has_different_config(self, net):
        '''
        Evaluates an existing network and returns a tuple containing a boolean
        indicating if the configuration is different and a list of differences.

        :param net: the inspection output for an existing network
        :return: (bool, list)
        '''
        different = False
        differences = []
        if self.parameters.driver and self.parameters.driver != net['Driver']:
            different = True
            differences.append('driver')
        if self.parameters.driver_options:
            if not net.get('Options'):
                different = True
                differences.append('driver_options')
            else:
                for key, value in self.parameters.driver_options.items():
                    if not (key in net['Options']) or value != net['Options'][key]:
                        different = True
                        differences.append('driver_options.%s' % key)

        if self.parameters.ipam_driver:
            if not net.get('IPAM') or net['IPAM']['Driver'] != self.parameters.ipam_driver:
                different = True
                differences.append('ipam_driver')

        if self.parameters.ipam_config is not None and self.parameters.ipam_config:
            if not net.get('IPAM') or not net['IPAM']['Config']:
                different = True
                differences.append('ipam_config')
            else:
                for idx, ipam_config in enumerate(self.parameters.ipam_config):
                    net_config = dict()
                    try:
                        ip_version = get_ip_version(ipam_config['subnet'])
                        for net_ipam_config in net['IPAM']['Config']:
                            if ip_version == get_ip_version(net_ipam_config['Subnet']):
                                net_config = net_ipam_config
                    except ValueError as e:
                        self.client.fail(str(e))

                    for key, value in ipam_config.items():
                        if value is None:
                            # due to recursive argument_spec, all keys are always present
                            # (but have default value None if not specified)
                            continue
                        camelkey = None
                        for net_key in net_config:
                            if key == net_key.lower():
                                camelkey = net_key
                                break
                        if not camelkey or net_config.get(camelkey) != value:
                            different = True
                            differences.append('ipam_config[%s].%s' % (idx, key))

        if self.parameters.enable_ipv6 is not None and self.parameters.enable_ipv6 != net.get('EnableIPv6', False):
            different = True
            differences.append('enable_ipv6')

        if self.parameters.internal is not None:
            if self.parameters.internal:
                if not net.get('Internal'):
                    different = True
                    differences.append('internal')
            else:
                if net.get('Internal'):
                    different = True
                    differences.append('internal')
        return different, differences

    def create_network(self):
        if not self.existing_network:
            params = dict(
                driver=self.parameters.driver,
                options=self.parameters.driver_options,
            )

            ipam_pools = []
            if self.parameters.ipam_config:
                for ipam_pool in self.parameters.ipam_config:
                    if HAS_DOCKER_PY_2 or HAS_DOCKER_PY_3:
                        ipam_pools.append(IPAMPool(**ipam_pool))
                    else:
                        ipam_pools.append(utils.create_ipam_pool(**ipam_pool))

            if self.parameters.ipam_driver or ipam_pools:
                # Only add ipam parameter if a driver was specified or if IPAM parameters
                # were specified. Leaving this parameter away can significantly speed up
                # creation; on my machine creation with this option needs ~15 seconds,
                # and without just a few seconds.
                if HAS_DOCKER_PY_2 or HAS_DOCKER_PY_3:
                    params['ipam'] = IPAMConfig(driver=self.parameters.ipam_driver,
                                                pool_configs=ipam_pools)
                else:
                    params['ipam'] = utils.create_ipam_config(driver=self.parameters.ipam_driver,
                                                              pool_configs=ipam_pools)

            if self.parameters.enable_ipv6 is not None:
                params['enable_ipv6'] = self.parameters.enable_ipv6
            if self.parameters.internal is not None:
                params['internal'] = self.parameters.internal

            if not self.check_mode:
                resp = self.client.create_network(self.parameters.network_name, **params)

                self.existing_network = self.client.inspect_network(resp['Id'])
            self.results['actions'].append("Created network %s with driver %s" % (self.parameters.network_name, self.parameters.driver))
            self.results['changed'] = True

    def remove_network(self):
        if self.existing_network:
            self.disconnect_all_containers()
            if not self.check_mode:
                self.client.remove_network(self.parameters.network_name)
            self.results['actions'].append("Removed network %s" % (self.parameters.network_name,))
            self.results['changed'] = True

    def is_container_connected(self, container_name):
        return container_name in container_names_in_network(self.existing_network)

    def connect_containers(self):
        for name in self.parameters.connected:
            if not self.is_container_connected(name):
                if not self.check_mode:
                    self.client.connect_container_to_network(name, self.parameters.network_name)
                self.results['actions'].append("Connected container %s" % (name,))
                self.results['changed'] = True

    def disconnect_missing(self):
        if not self.existing_network:
            return
        containers = self.existing_network['Containers']
        if not containers:
            return
        for c in containers.values():
            name = c['Name']
            if name not in self.parameters.connected:
                self.disconnect_container(name)

    def disconnect_all_containers(self):
        containers = self.client.inspect_network(self.parameters.network_name)['Containers']
        if not containers:
            return
        for cont in containers.values():
            self.disconnect_container(cont['Name'])

    def disconnect_container(self, container_name):
        if not self.check_mode:
            self.client.disconnect_container_from_network(container_name, self.parameters.network_name)
        self.results['actions'].append("Disconnected container %s" % (container_name,))
        self.results['changed'] = True

    def present(self):
        different = False
        differences = []
        if self.existing_network:
            different, differences = self.has_different_config(self.existing_network)

        if self.parameters.force or different:
            self.remove_network()
            self.existing_network = None

        self.create_network()
        self.connect_containers()
        if not self.parameters.appends:
            self.disconnect_missing()

        if self.diff or self.check_mode or self.parameters.debug:
            self.results['diff'] = differences

        if not self.check_mode and not self.parameters.debug:
            self.results.pop('actions')

        self.results['ansible_facts'] = {u'docker_network': self.get_existing_network()}

    def absent(self):
        self.remove_network()


def main():
    argument_spec = dict(
        network_name=dict(type='str', required=True, aliases=['name']),
        connected=dict(type='list', default=[], aliases=['containers'], elements='str'),
        state=dict(type='str', default='present', choices=['present', 'absent']),
        driver=dict(type='str', default='bridge'),
        driver_options=dict(type='dict', default={}),
        force=dict(type='bool', default=False),
        appends=dict(type='bool', default=False, aliases=['incremental']),
        ipam_driver=dict(type='str'),
        ipam_options=dict(type='dict', default={}, removed_in_version='2.12', options=dict(
            subnet=dict(type='str'),
            iprange=dict(type='str'),
            gateway=dict(type='str'),
            aux_addresses=dict(type='dict'),
        )),
        ipam_config=dict(type='list', elements='dict', options=dict(
            subnet=dict(type='str'),
            iprange=dict(type='str'),
            gateway=dict(type='str'),
            aux_addresses=dict(type='dict'),
        )),
        enable_ipv6=dict(type='bool'),
        internal=dict(type='bool'),
        debug=dict(type='bool', default=False)
    )

    mutually_exclusive = [
        ('ipam_config', 'ipam_options')
    ]

    client = AnsibleDockerClient(
        argument_spec=argument_spec,
        mutually_exclusive=mutually_exclusive,
        supports_check_mode=True,
        min_docker_version='1.10.0'
        # "The docker server >= 1.10.0"
    )

    cm = DockerNetworkManager(client)
    client.module.exit_json(**cm.results)


if __name__ == '__main__':
    main()