#!/usr/bin/python # # (c) 2015, Steve Gargan <steve.gargan@gmail.com> # 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 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 I(check_name) and optionally a I(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 U(http://consul.io) for more details." requirements: - python-consul - requests author: "Steve Gargan (@sgargan)" options: state: type: str description: - register or deregister the consul service, defaults to present default: present choices: ['present', 'absent'] service_name: type: str description: - Unique name for the service on a node, must be unique per node, required if registering a service. May be omitted if registering a node level check service_id: type: str description: - the ID for the service, must be unique per node. If I(state=absent), defaults to the service name if supplied. host: type: str description: - host of the consul agent defaults to localhost default: localhost port: type: int description: - the port on which the consul agent is running default: 8500 scheme: type: str description: - the protocol scheme on which the consul agent is running default: http validate_certs: description: - whether to verify the TLS certificate of the consul agent type: bool default: 'yes' notes: type: str description: - Notes to attach to check when registering it. service_port: type: int description: - the port on which the service is listening. Can optionally be supplied for registration of a service, i.e. if I(service_name) or I(service_id) is set service_address: type: str description: - the address to advertise that the service will be listening on. This value will be passed as the I(address) parameter to Consul's U(/v1/agent/service/register) API method, so refer to the Consul API documentation for further details. tags: type: list elements: str description: - tags that will be attached to the service registration. script: type: str description: - the script/command that will be run periodically to check the health of the service. Scripts require I(interval) and vice versa. interval: type: str 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 C(15s) or C(1m). If no suffix is supplied, m will be used by default e.g. C(1) will be C(1m). Required if the I(script) parameter is specified. check_id: type: str description: - an ID for the service check. If I(state=absent), defaults to I(check_name). Ignored if part of a service definition. check_name: type: str description: - a name for the service check. Required if standalone, ignored if part of service definition. ttl: type: str description: - checks can be registered with a ttl instead of a I(script) and I(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 C(15s) or C(1m). If no suffix is supplied, C(m) will be used by default e.g. C(1) will be C(1m) tcp: type: str description: - Checks can be registered with a TCP port. This means that consul will check if the connection attempt to that port is successful (that is, the port is currently accepting connections). The format is C(host:port), for example C(localhost:80). I(interval) must also be provided with this option. version_added: '1.3.0' http: type: str description: - checks can be registered with an HTTP endpoint. This means that consul will check that the http endpoint returns a successful HTTP status. I(interval) must also be provided with this option. timeout: type: str description: - A custom HTTP check timeout. The consul default is 10 seconds. Similar to the interval this is a number with a C(s) or C(m) suffix to signify the units of seconds or minutes, e.g. C(15s) or C(1m). token: type: str description: - the token key identifying an ACL rule set. May be required to register services. ''' EXAMPLES = ''' - name: Register nginx service with the local consul agent community.general.consul: service_name: nginx service_port: 80 - name: Register nginx service with curl check community.general.consul: service_name: nginx service_port: 80 script: curl http://localhost interval: 60s - name: register nginx with a tcp check community.general.consul: service_name: nginx service_port: 80 interval: 60s tcp: localhost:80 - name: Register nginx with an http check community.general.consul: service_name: nginx service_port: 80 interval: 60s http: http://localhost:80/status - name: Register external service nginx available at 10.1.5.23 community.general.consul: service_name: nginx service_port: 80 service_address: 10.1.5.23 - name: Register nginx with some service tags community.general.consul: service_name: nginx service_port: 80 tags: - prod - webservers - name: Remove nginx service community.general.consul: service_name: nginx state: absent - name: Register celery worker service community.general.consul: service_name: celery-worker tags: - prod - worker - name: Create a node level check to test disk usage community.general.consul: check_name: Disk usage check_id: disk_usage script: /opt/disk_usage.py interval: 5m - name: Register an http check against a service that's already registered community.general.consul: check_name: nginx-check2 check_id: nginx-check2 service_id: nginx interval: 60s http: http://localhost:80/morestatus ''' try: import consul from requests.exceptions import ConnectionError class PatchedConsulAgentService(consul.Consul.Agent.Service): def deregister(self, service_id, token=None): params = {} if token: params['token'] = token return self.agent.http.put(consul.base.CB.bool(), '/v1/agent/service/deregister/%s' % service_id, params=params) python_consul_installed = True except ImportError: python_consul_installed = False import re from ansible.module_utils.basic import AnsibleModule 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 and not check.service_id: 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, tcp=check.tcp, http=check.http, timeout=check.timeout, service_id=check.service_id) 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 current agent ''' result = service changed = False consul_api = get_consul_api(module) existing = get_service_by_id_or_name(consul_api, service.id) # there is no way to retrieve the details of checks so if a check is present # in the service it must be re-registered 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_or_name(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=[check.to_dict() for check in 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_or_name(consul_api, service_id) if service: consul_api.agent.service.deregister(service_id, token=module.params.get('token')) module.exit_json(changed=True, id=service_id) module.exit_json(changed=False, id=service_id) def get_consul_api(module): consulClient = consul.Consul(host=module.params.get('host'), port=module.params.get('port'), scheme=module.params.get('scheme'), verify=module.params.get('validate_certs'), token=module.params.get('token')) consulClient.agent.service = PatchedConsulAgentService(consulClient) return consulClient def get_service_by_id_or_name(consul_api, service_id_or_name): ''' iterate the registered services and find one with the given id ''' for name, service in consul_api.agent.services().items(): if service['ID'] == service_id_or_name or service['Service'] == service_id_or_name: return ConsulService(loaded=service) def parse_check(module): if len([p for p in (module.params.get('script'), module.params.get('ttl'), module.params.get('tcp'), module.params.get('http')) if p]) > 1: module.fail_json( msg='checks are either script, tcp, http or ttl driven, supplying more than one does not make sense') if module.params.get('check_id') or module.params.get('script') or module.params.get('ttl') or module.params.get('tcp') or module.params.get('http'): 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'), module.params.get('tcp'), module.params.get('http'), module.params.get('timeout'), module.params.get('service_id'), ) def parse_service(module): if module.params.get('service_name'): return ConsulService( module.params.get('service_id'), module.params.get('service_name'), module.params.get('service_address'), module.params.get('service_port'), module.params.get('tags'), ) elif not module.params.get('service_name'): module.fail_json(msg="service_name is required to configure a service.") class ConsulService(object): def __init__(self, service_id=None, name=None, address=None, port=-1, tags=None, loaded=None): self.id = self.name = name if service_id: self.id = service_id self.address = address 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): optional = {} if self.port: optional['port'] = self.port if len(self.checks) > 0: optional['check'] = self.checks[0].check consul_api.agent.service.register( self.name, service_id=self.id, address=self.address, tags=self.tags, **optional) 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(object): def __init__(self, check_id, name, node=None, host='localhost', script=None, interval=None, ttl=None, notes=None, tcp=None, http=None, timeout=None, service_id=None): self.check_id = self.name = name if check_id: self.check_id = check_id self.service_id = service_id self.notes = notes self.node = node self.host = host self.interval = self.validate_duration('interval', interval) self.ttl = self.validate_duration('ttl', ttl) self.script = script self.tcp = tcp self.http = http self.timeout = self.validate_duration('timeout', timeout) self.check = None if script: self.check = consul.Check.script(script, self.interval) if ttl: self.check = consul.Check.ttl(self.ttl) if http: if interval is None: raise Exception('http check must specify interval') self.check = consul.Check.http(http, self.interval, self.timeout) if tcp: if interval is None: raise Exception('tcp check must specify interval') regex = r"(?P<host>.*)(?::)(?P<port>(?:[0-9]+))$" match = re.match(regex, tcp) if match is None: raise Exception('tcp check must be in host:port format') self.check = consul.Check.tcp(match.group('host').strip('[]'), int(match.group('port')), self.interval) 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)): duration = "{0}s".format(duration) return duration def register(self, consul_api): consul_api.agent.check.register(self.name, check_id=self.check_id, service_id=self.service_id, notes=self.notes, check=self.check) def __eq__(self, other): return (isinstance(other, self.__class__) and self.check_id == other.check_id and self.service_id == other.service_id and self.name == other.name and self.script == other.script and self.interval == other.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') self._add(data, 'tcp') self._add(data, 'http') self._add(data, 'timeout') self._add(data, 'service_id') return data def _add(self, data, key, attr=None): try: if attr is None: attr = key data[key] = getattr(self, attr) except Exception: pass def test_dependencies(module): if not python_consul_installed: module.fail_json(msg="python-consul required for this module. see https://python-consul.readthedocs.io/en/latest/#installation") def main(): module = AnsibleModule( argument_spec=dict( host=dict(default='localhost'), port=dict(default=8500, type='int'), scheme=dict(default='http'), validate_certs=dict(default=True, type='bool'), check_id=dict(), check_name=dict(), check_node=dict(), check_host=dict(), notes=dict(), script=dict(), service_id=dict(), service_name=dict(), service_address=dict(type='str'), service_port=dict(type='int'), state=dict(default='present', choices=['present', 'absent']), interval=dict(type='str'), ttl=dict(type='str'), tcp=dict(type='str'), http=dict(type='str'), timeout=dict(type='str'), tags=dict(type='list', elements='str'), token=dict(no_log=True) ), supports_check_mode=False, ) test_dependencies(module) try: register_with_consul(module) except ConnectionError as 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 as e: module.fail_json(msg=str(e)) if __name__ == '__main__': main()