Consul Service module for Ansible

consul

# -*- coding: utf-8 -*-
# -*- mode: python -*-

DOCUMENTATION = '''
---
module: consul
short_description: Consul Agent API interaction with Docker
description:
     - This module wraps the Consul API making calls to the Agent end points
       to register and unregister services.
options:
  docker_name:
    description:
      - The name of the docker file the service relates to.
    required: True
    default: None
  docker_id:
    description:
      - The ID that relates to this service, e.g HTTP
      required: False
      default: {{ docker_name }}
  port:
    description:
      - The port which the service to be registered runs on.
      required: True
      default: None
  tags:
    description:
      - Any tags as a list that should be registered for the service.
    required: False
    default: None
  check:
    description:
      - The path to a script which can check the service is working
    required: False
    default: None
  check_args:
    description:
      - Any arguments to be passed on to the check as a string
    required: False
    default: None
  docker_remove:
    description:
      - Should we remove or leave a failed docker container from the system
    required: False
    default: True

author: Mark Olliver
'''

EXAMPLES = '''
# Example that checks if Sentinel docker is running, if it is and the service
# is not registered then we register the service. If the docker is not running
# then we deregister the service if it was registered. If the remove flag is
# set then we remove the docker container if it is not running to tidy up the
# system.
-  consul:
    docker_name: "sentinel{{ env_suffix }}"
    docker_id: "sentinel{{ env_suffix }}"
    port: 26379
    tags: "{{ env_suffix }}"
    check: redis_check.py
    check_args: "--docker_name sentinel{{ env_suffix }} --docker_id
                sentinel{{ env_suffix }} --port 26379"
'''


'''
TODO(Mark): Extend to use check mode which will allow for reporting if
# a service is registered
'''


import urllib2
import json


def register_service(module, docker_name, docker_id, port,
                     tags, check, check_args):
    url = "http://localhost:8500/v1/agent/service/register"
    if (check):
        data = {'ID': docker_id,
                'Name': docker_name,
                'Port': port,
                'Tags': [tags],
                'Check': {'Script': "/checks/" + check + " " + check_args,
                          'Interval': "60s"
                          }
                }
    else:
        data = {'ID': docker_id,
                'Name': docker_name,
                'Port': port,
                'Tags': [tags]
                }
    req = urllib2.Request(url, json.dumps(data))
    try:
        response = urllib2.urlopen(req)
        content = (response.read())
    except urllib2.HTTPError, e:
        module.fail_json(msg="Consul Registration Error")

    module.exit_json(changed=True, msg=" Registered Service: " + docker_id)


def deregister_service(module, docker_id, docker_name, docker_remove):
    url = "http://localhost:8500/v1/agent/service/deregister/"
    req = urllib2.Request(url + docker_id)
    try:
        content = urllib2.urlopen(req)
    except urllib2.HTTPError, e:
        module.fail_json(msg="Could not deregister service: " + docker_id)

    if (docker_remove):
        import docker
        try:
            docker.remove_container(docker_name)
            module.exit_json(changed=True,
                             msg="Deregistered Service and removed Container: \
                             " + docker_id)
        except:
            pass

    module.exit_json(changed=True, msg="Deregistered Service: " + docker_id)


def check_docker_running(docker_name):
    import docker
    c = docker.Client(base_url='unix://var/run/docker.sock',
                      version='1.11',
                      timeout=10)
    containers = c.containers(quiet=False, all=False, trunc=True, latest=False,
                              since=None, before=None, limit=-1)
    for x in range(len(containers)):
        if docker_name in containers[x]["Names"][0]:
            print containers[x]["Names"][0]
            if "Up" in containers[x]["Status"]:
                return True


def check_service_registered(module, docker_name, docker_id):
    url = "http://localhost:8500/v1/agent/services"
    req = urllib2.Request(url)
    try:
        content = json.load(urllib2.urlopen(req))
    except urllib2.HTTPError, e:
        module.fail_json(msg="Could not check service: " + docker_id)

    try:
        if docker_name == content[docker_id]["Service"]:
            return True
        else:
            return False
    except KeyError, e:
        return False


def main():
    module = AnsibleModule(
        argument_spec=dict(
            docker_name=dict(required=True),
            docker_id=dict(required=False),
            port=dict(required=True),
            tags=dict(required=False),
            check=dict(require=False),
            check_args=dict(required=False),
            docker_remove=dict(required=False)
        ),
        supports_check_mode=False
    )
    docker_name = module.params.get('docker_name')
    docker_id = module.params.get('docker_id') or docker_name
    port = module.params.get('port')
    tags = module.params.get('tags') or None
    check = module.params.get('check') or None
    check_args = module.params.get('check_args') or ""
    docker_remove = module.params.get('docker_remove') or True
    docker_running = check_docker_running(docker_name)
    service_registered = check_service_registered(module,
                                                  docker_name,
                                                  docker_id)
    if docker_running:
        if service_registered:
            module.exit_json(changed=False,
                             msg="Docker running and service registered")
        else:
            register_service(module, docker_name, docker_id, port,
                             tags, check, check_args)
    else:
        deregister_service(module, docker_id, docker_name, docker_remove)


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

main()