#!/usr/bin/python # # (c) 2015, Steve Gargan # # 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 . DOCUMENTATION = """ module: consul short_description: "Add, modify & delete services within a consul cluster." description: - Registers services and checks for an agent with a consul cluster. A service is some process running on the agent node that should be advertised by consul's discovery mechanism. It may optionally supply a check definition, a periodic service test to notify the consul cluster of service's health. - "Checks may also be registered per node e.g. disk usage, or cpu usage and notify the health of the entire node to the cluster. Service level checks do not require a check name or id as these are derived by Consul from the Service name and id respectively by appending 'service:' Node level checks require a check_name and optionally a check_id." - Currently, there is no complete way to retrieve the script, interval or ttl metadata for a registered check. Without this metadata it is not possible to tell if the data supplied with ansible represents a change to a check. As a result this does not attempt to determine changes and will always report a changed occurred. An api method is planned to supply this metadata so at that stage change management will be added. - "See http://consul.io for more details." requirements: - "python >= 2.6" - python-consul - requests version_added: "2.0" author: "Steve Gargan (@sgargan)" options: state: description: - register or deregister the consul service, defaults to present required: true choices: ['present', 'absent'] service_name: description: - Unique name for the service on a node, must be unique per node, required if registering a service. May be ommitted if registering a node level check required: false service_id: description: - the ID for the service, must be unique per node, defaults to the service name if the service name is supplied required: false default: service_name if supplied host: description: - host of the consul agent defaults to localhost required: false default: localhost port: description: - the port on which the consul agent is running required: false default: 8500 notes: description: - Notes to attach to check when registering it. required: false default: None service_port: description: - the port on which the service is listening required for registration of a service, i.e. if service_name or service_id is set required: false tags: description: - a list of tags that will be attached to the service registration. required: false default: None script: description: - the script/command that will be run periodically to check the health of the service. Scripts require an interval and vise versa required: false default: None interval: description: - the interval at which the service check will be run. This is a number with a s or m suffix to signify the units of seconds or minutes e.g 15s or 1m. If no suffix is supplied, m will be used by default e.g. 1 will be 1m. Required if the script param is specified. required: false default: None check_id: description: - an ID for the service check, defaults to the check name, ignored if part of a service definition. required: false default: None check_name: description: - a name for the service check, defaults to the check id. required if standalone, ignored if part of service definition. required: false default: None ttl: description: - checks can be registered with a ttl instead of a script and interval this means that the service will check in with the agent before the ttl expires. If it doesn't the check will be considered failed. Required if registering a check and the script an interval are missing Similar to the interval this is a number with a s or m suffix to signify the units of seconds or minutes e.g 15s or 1m. If no suffix is supplied, m will be used by default e.g. 1 will be 1m required: false default: None token: description: - the token key indentifying an ACL rule set. May be required to register services. required: false default: None """ EXAMPLES = ''' - name: register nginx service with the local consul agent consul: service_name: nginx service_port: 80 - name: register nginx service with curl check consul: service_name: nginx service_port: 80 script: "curl http://localhost" interval: 60s - name: register nginx with some service tags consul: service_name: nginx service_port: 80 tags: - prod - webservers - name: remove nginx service consul: service_name: nginx state: absent - name: create a node level check to test disk usage consul: check_name: Disk usage check_id: disk_usage script: "/opt/disk_usage.py" interval: 5m ''' import sys try: import json except ImportError: import simplejson as json try: import consul from requests.exceptions import ConnectionError python_consul_installed = True except ImportError, e: python_consul_installed = False def register_with_consul(module): state = module.params.get('state') if state == 'present': add(module) else: remove(module) def add(module): ''' adds a service or a check depending on supplied configuration''' check = parse_check(module) service = parse_service(module) if not service and not check: module.fail_json(msg='a name and port are required to register a service') if service: if check: service.add_check(check) add_service(module, service) elif check: add_check(module, check) def remove(module): ''' removes a service or a check ''' service_id = module.params.get('service_id') or module.params.get('service_name') check_id = module.params.get('check_id') or module.params.get('check_name') if not (service_id or check_id): module.fail_json(msg='services and checks are removed by id or name.'\ ' please supply a service id/name or a check id/name') if service_id: remove_service(module, service_id) else: remove_check(module, check_id) def add_check(module, check): ''' registers a check with the given agent. currently there is no way retrieve the full metadata of an existing check through the consul api. Without this we can't compare to the supplied check and so we must assume a change. ''' if not check.name: module.fail_json(msg='a check name is required for a node level check,'\ ' one not attached to a service') consul_api = get_consul_api(module) check.register(consul_api) module.exit_json(changed=True, check_id=check.check_id, check_name=check.name, script=check.script, interval=check.interval, ttl=check.ttl) def remove_check(module, check_id): ''' removes a check using its id ''' consul_api = get_consul_api(module) if check_id in consul_api.agent.checks(): consul_api.agent.check.deregister(check_id) module.exit_json(changed=True, id=check_id) module.exit_json(changed=False, id=check_id) def add_service(module, service): ''' registers a service with the the current agent ''' result = service changed = False consul_api = get_consul_api(module) existing = get_service_by_id(consul_api, service.id) # there is no way to retreive the details of checks so if a check is present # in the service it must be reregistered if service.has_checks() or not existing or not existing == service: service.register(consul_api) # check that it registered correctly registered = get_service_by_id(consul_api, service.id) if registered: result = registered changed = True module.exit_json(changed=changed, service_id=result.id, service_name=result.name, service_port=result.port, checks=map(lambda x: x.to_dict(), service.checks), tags=result.tags) def remove_service(module, service_id): ''' deregister a service from the given agent using its service id ''' consul_api = get_consul_api(module) service = get_service_by_id(consul_api, service_id) if service: consul_api.agent.service.deregister(service_id) module.exit_json(changed=True, id=service_id) module.exit_json(changed=False, id=service_id) def get_consul_api(module, token=None): return consul.Consul(host=module.params.get('host'), port=module.params.get('port'), token=module.params.get('token')) def get_service_by_id(consul_api, service_id): ''' iterate the registered services and find one with the given id ''' for name, service in consul_api.agent.services().iteritems(): if service['ID'] == service_id: return ConsulService(loaded=service) def parse_check(module): if module.params.get('script') and module.params.get('ttl'): module.fail_json( msg='check are either script or ttl driven, supplying both does'\ ' not make sense') if module.params.get('check_id') or module.params.get('script') or module.params.get('ttl'): return ConsulCheck( module.params.get('check_id'), module.params.get('check_name'), module.params.get('check_node'), module.params.get('check_host'), module.params.get('script'), module.params.get('interval'), module.params.get('ttl'), module.params.get('notes') ) def parse_service(module): if module.params.get('service_name') and module.params.get('service_port'): return ConsulService( module.params.get('service_id'), module.params.get('service_name'), module.params.get('service_port'), module.params.get('tags'), ) elif module.params.get('service_name') and not module.params.get('service_port'): module.fail_json( msg="service_name supplied but no service_port, a port is required"\ " to configure a service. Did you configure the 'port' "\ "argument meaning 'service_port'?") class ConsulService(): def __init__(self, service_id=None, name=None, port=-1, tags=None, loaded=None): self.id = self.name = name if service_id: self.id = service_id self.port = port self.tags = tags self.checks = [] if loaded: self.id = loaded['ID'] self.name = loaded['Service'] self.port = loaded['Port'] self.tags = loaded['Tags'] def register(self, consul_api): if len(self.checks) > 0: check = self.checks[0] consul_api.agent.service.register( self.name, service_id=self.id, port=self.port, tags=self.tags, script=check.script, interval=check.interval, ttl=check.ttl) else: consul_api.agent.service.register( self.name, service_id=self.id, port=self.port, tags=self.tags) def add_check(self, check): self.checks.append(check) def checks(self): return self.checks def has_checks(self): return len(self.checks) > 0 def __eq__(self, other): return (isinstance(other, self.__class__) and self.id == other.id and self.name == other.name and self.port == other.port and self.tags == other.tags) def __ne__(self, other): return not self.__eq__(other) def to_dict(self): data = {'id': self.id, "name": self.name} if self.port: data['port'] = self.port if self.tags and len(self.tags) > 0: data['tags'] = self.tags if len(self.checks) > 0: data['check'] = self.checks[0].to_dict() return data class ConsulCheck(): def __init__(self, check_id, name, node=None, host='localhost', script=None, interval=None, ttl=None, notes=None): self.check_id = self.name = name if check_id: self.check_id = check_id self.script = script self.interval = self.validate_duration('interval', interval) self.ttl = self.validate_duration('ttl', ttl) self.notes = notes self.node = node self.host = host def validate_duration(self, name, duration): if duration: duration_units = ['ns', 'us', 'ms', 's', 'm', 'h'] if not any((duration.endswith(suffix) for suffix in duration_units)): raise Exception('Invalid %s %s you must specify units (%s)' % (name, duration, ', '.join(duration_units))) return duration def register(self, consul_api): consul_api.agent.check.register(self.name, check_id=self.check_id, script=self.script, interval=self.interval, ttl=self.ttl, notes=self.notes) def __eq__(self, other): return (isinstance(other, self.__class__) and self.check_id == other.check_id and self.name == other.name and self.script == script and self.interval == interval) def __ne__(self, other): return not self.__eq__(other) def to_dict(self): data = {} self._add(data, 'id', attr='check_id') self._add(data, 'name', attr='check_name') self._add(data, 'script') self._add(data, 'node') self._add(data, 'notes') self._add(data, 'host') self._add(data, 'interval') self._add(data, 'ttl') return data def _add(self, data, key, attr=None): try: if attr == None: attr = key data[key] = getattr(self, attr) except: pass def test_dependencies(module): if not python_consul_installed: module.fail_json(msg="python-consul required for this module. "\ "see http://python-consul.readthedocs.org/en/latest/#installation") def main(): module = AnsibleModule( argument_spec=dict( host=dict(default='localhost'), port=dict(default=8500, type='int'), check_id=dict(required=False), check_name=dict(required=False), check_node=dict(required=False), check_host=dict(required=False), notes=dict(required=False), script=dict(required=False), service_id=dict(required=False), service_name=dict(required=False), service_port=dict(required=False, type='int'), state=dict(default='present', choices=['present', 'absent']), interval=dict(required=False, type='str'), ttl=dict(required=False, type='str'), tags=dict(required=False, type='list'), token=dict(required=False) ), supports_check_mode=False, ) test_dependencies(module) try: register_with_consul(module) except ConnectionError, e: module.fail_json(msg='Could not connect to consul agent at %s:%s, error was %s' % ( module.params.get('host'), module.params.get('port'), str(e))) except Exception, e: module.fail_json(msg=str(e)) # import module snippets from ansible.module_utils.basic import * if __name__ == '__main__': main()