diff options
Diffstat (limited to 'contrail-analytics/hooks/charmhelpers/core/services')
3 files changed, 657 insertions, 0 deletions
diff --git a/contrail-analytics/hooks/charmhelpers/core/services/__init__.py b/contrail-analytics/hooks/charmhelpers/core/services/__init__.py new file mode 100644 index 0000000..61fd074 --- /dev/null +++ b/contrail-analytics/hooks/charmhelpers/core/services/__init__.py @@ -0,0 +1,16 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +from .base import * # NOQA +from .helpers import * # NOQA diff --git a/contrail-analytics/hooks/charmhelpers/core/services/base.py b/contrail-analytics/hooks/charmhelpers/core/services/base.py new file mode 100644 index 0000000..ca9dc99 --- /dev/null +++ b/contrail-analytics/hooks/charmhelpers/core/services/base.py @@ -0,0 +1,351 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import os +import json +from inspect import getargspec +from collections import Iterable, OrderedDict + +from charmhelpers.core import host +from charmhelpers.core import hookenv + + +__all__ = ['ServiceManager', 'ManagerCallback', + 'PortManagerCallback', 'open_ports', 'close_ports', 'manage_ports', + 'service_restart', 'service_stop'] + + +class ServiceManager(object): + def __init__(self, services=None): + """ + Register a list of services, given their definitions. + + Service definitions are dicts in the following formats (all keys except + 'service' are optional):: + + { + "service": <service name>, + "required_data": <list of required data contexts>, + "provided_data": <list of provided data contexts>, + "data_ready": <one or more callbacks>, + "data_lost": <one or more callbacks>, + "start": <one or more callbacks>, + "stop": <one or more callbacks>, + "ports": <list of ports to manage>, + } + + The 'required_data' list should contain dicts of required data (or + dependency managers that act like dicts and know how to collect the data). + Only when all items in the 'required_data' list are populated are the list + of 'data_ready' and 'start' callbacks executed. See `is_ready()` for more + information. + + The 'provided_data' list should contain relation data providers, most likely + a subclass of :class:`charmhelpers.core.services.helpers.RelationContext`, + that will indicate a set of data to set on a given relation. + + The 'data_ready' value should be either a single callback, or a list of + callbacks, to be called when all items in 'required_data' pass `is_ready()`. + Each callback will be called with the service name as the only parameter. + After all of the 'data_ready' callbacks are called, the 'start' callbacks + are fired. + + The 'data_lost' value should be either a single callback, or a list of + callbacks, to be called when a 'required_data' item no longer passes + `is_ready()`. Each callback will be called with the service name as the + only parameter. After all of the 'data_lost' callbacks are called, + the 'stop' callbacks are fired. + + The 'start' value should be either a single callback, or a list of + callbacks, to be called when starting the service, after the 'data_ready' + callbacks are complete. Each callback will be called with the service + name as the only parameter. This defaults to + `[host.service_start, services.open_ports]`. + + The 'stop' value should be either a single callback, or a list of + callbacks, to be called when stopping the service. If the service is + being stopped because it no longer has all of its 'required_data', this + will be called after all of the 'data_lost' callbacks are complete. + Each callback will be called with the service name as the only parameter. + This defaults to `[services.close_ports, host.service_stop]`. + + The 'ports' value should be a list of ports to manage. The default + 'start' handler will open the ports after the service is started, + and the default 'stop' handler will close the ports prior to stopping + the service. + + + Examples: + + The following registers an Upstart service called bingod that depends on + a mongodb relation and which runs a custom `db_migrate` function prior to + restarting the service, and a Runit service called spadesd:: + + manager = services.ServiceManager([ + { + 'service': 'bingod', + 'ports': [80, 443], + 'required_data': [MongoRelation(), config(), {'my': 'data'}], + 'data_ready': [ + services.template(source='bingod.conf'), + services.template(source='bingod.ini', + target='/etc/bingod.ini', + owner='bingo', perms=0400), + ], + }, + { + 'service': 'spadesd', + 'data_ready': services.template(source='spadesd_run.j2', + target='/etc/sv/spadesd/run', + perms=0555), + 'start': runit_start, + 'stop': runit_stop, + }, + ]) + manager.manage() + """ + self._ready_file = os.path.join(hookenv.charm_dir(), 'READY-SERVICES.json') + self._ready = None + self.services = OrderedDict() + for service in services or []: + service_name = service['service'] + self.services[service_name] = service + + def manage(self): + """ + Handle the current hook by doing The Right Thing with the registered services. + """ + hookenv._run_atstart() + try: + hook_name = hookenv.hook_name() + if hook_name == 'stop': + self.stop_services() + else: + self.reconfigure_services() + self.provide_data() + except SystemExit as x: + if x.code is None or x.code == 0: + hookenv._run_atexit() + hookenv._run_atexit() + + def provide_data(self): + """ + Set the relation data for each provider in the ``provided_data`` list. + + A provider must have a `name` attribute, which indicates which relation + to set data on, and a `provide_data()` method, which returns a dict of + data to set. + + The `provide_data()` method can optionally accept two parameters: + + * ``remote_service`` The name of the remote service that the data will + be provided to. The `provide_data()` method will be called once + for each connected service (not unit). This allows the method to + tailor its data to the given service. + * ``service_ready`` Whether or not the service definition had all of + its requirements met, and thus the ``data_ready`` callbacks run. + + Note that the ``provided_data`` methods are now called **after** the + ``data_ready`` callbacks are run. This gives the ``data_ready`` callbacks + a chance to generate any data necessary for the providing to the remote + services. + """ + for service_name, service in self.services.items(): + service_ready = self.is_ready(service_name) + for provider in service.get('provided_data', []): + for relid in hookenv.relation_ids(provider.name): + units = hookenv.related_units(relid) + if not units: + continue + remote_service = units[0].split('/')[0] + argspec = getargspec(provider.provide_data) + if len(argspec.args) > 1: + data = provider.provide_data(remote_service, service_ready) + else: + data = provider.provide_data() + if data: + hookenv.relation_set(relid, data) + + def reconfigure_services(self, *service_names): + """ + Update all files for one or more registered services, and, + if ready, optionally restart them. + + If no service names are given, reconfigures all registered services. + """ + for service_name in service_names or self.services.keys(): + if self.is_ready(service_name): + self.fire_event('data_ready', service_name) + self.fire_event('start', service_name, default=[ + service_restart, + manage_ports]) + self.save_ready(service_name) + else: + if self.was_ready(service_name): + self.fire_event('data_lost', service_name) + self.fire_event('stop', service_name, default=[ + manage_ports, + service_stop]) + self.save_lost(service_name) + + def stop_services(self, *service_names): + """ + Stop one or more registered services, by name. + + If no service names are given, stops all registered services. + """ + for service_name in service_names or self.services.keys(): + self.fire_event('stop', service_name, default=[ + manage_ports, + service_stop]) + + def get_service(self, service_name): + """ + Given the name of a registered service, return its service definition. + """ + service = self.services.get(service_name) + if not service: + raise KeyError('Service not registered: %s' % service_name) + return service + + def fire_event(self, event_name, service_name, default=None): + """ + Fire a data_ready, data_lost, start, or stop event on a given service. + """ + service = self.get_service(service_name) + callbacks = service.get(event_name, default) + if not callbacks: + return + if not isinstance(callbacks, Iterable): + callbacks = [callbacks] + for callback in callbacks: + if isinstance(callback, ManagerCallback): + callback(self, service_name, event_name) + else: + callback(service_name) + + def is_ready(self, service_name): + """ + Determine if a registered service is ready, by checking its 'required_data'. + + A 'required_data' item can be any mapping type, and is considered ready + if `bool(item)` evaluates as True. + """ + service = self.get_service(service_name) + reqs = service.get('required_data', []) + return all(bool(req) for req in reqs) + + def _load_ready_file(self): + if self._ready is not None: + return + if os.path.exists(self._ready_file): + with open(self._ready_file) as fp: + self._ready = set(json.load(fp)) + else: + self._ready = set() + + def _save_ready_file(self): + if self._ready is None: + return + with open(self._ready_file, 'w') as fp: + json.dump(list(self._ready), fp) + + def save_ready(self, service_name): + """ + Save an indicator that the given service is now data_ready. + """ + self._load_ready_file() + self._ready.add(service_name) + self._save_ready_file() + + def save_lost(self, service_name): + """ + Save an indicator that the given service is no longer data_ready. + """ + self._load_ready_file() + self._ready.discard(service_name) + self._save_ready_file() + + def was_ready(self, service_name): + """ + Determine if the given service was previously data_ready. + """ + self._load_ready_file() + return service_name in self._ready + + +class ManagerCallback(object): + """ + Special case of a callback that takes the `ServiceManager` instance + in addition to the service name. + + Subclasses should implement `__call__` which should accept three parameters: + + * `manager` The `ServiceManager` instance + * `service_name` The name of the service it's being triggered for + * `event_name` The name of the event that this callback is handling + """ + def __call__(self, manager, service_name, event_name): + raise NotImplementedError() + + +class PortManagerCallback(ManagerCallback): + """ + Callback class that will open or close ports, for use as either + a start or stop action. + """ + def __call__(self, manager, service_name, event_name): + service = manager.get_service(service_name) + new_ports = service.get('ports', []) + port_file = os.path.join(hookenv.charm_dir(), '.{}.ports'.format(service_name)) + if os.path.exists(port_file): + with open(port_file) as fp: + old_ports = fp.read().split(',') + for old_port in old_ports: + if bool(old_port): + old_port = int(old_port) + if old_port not in new_ports: + hookenv.close_port(old_port) + with open(port_file, 'w') as fp: + fp.write(','.join(str(port) for port in new_ports)) + for port in new_ports: + if event_name == 'start': + hookenv.open_port(port) + elif event_name == 'stop': + hookenv.close_port(port) + + +def service_stop(service_name): + """ + Wrapper around host.service_stop to prevent spurious "unknown service" + messages in the logs. + """ + if host.service_running(service_name): + host.service_stop(service_name) + + +def service_restart(service_name): + """ + Wrapper around host.service_restart to prevent spurious "unknown service" + messages in the logs. + """ + if host.service_available(service_name): + if host.service_running(service_name): + host.service_restart(service_name) + else: + host.service_start(service_name) + + +# Convenience aliases +open_ports = close_ports = manage_ports = PortManagerCallback() diff --git a/contrail-analytics/hooks/charmhelpers/core/services/helpers.py b/contrail-analytics/hooks/charmhelpers/core/services/helpers.py new file mode 100644 index 0000000..3e6e30d --- /dev/null +++ b/contrail-analytics/hooks/charmhelpers/core/services/helpers.py @@ -0,0 +1,290 @@ +# Copyright 2014-2015 Canonical Limited. +# +# Licensed under the Apache License, Version 2.0 (the "License"); +# you may not use this file except in compliance with the License. +# You may obtain a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, +# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +# See the License for the specific language governing permissions and +# limitations under the License. + +import os +import yaml + +from charmhelpers.core import hookenv +from charmhelpers.core import host +from charmhelpers.core import templating + +from charmhelpers.core.services.base import ManagerCallback + + +__all__ = ['RelationContext', 'TemplateCallback', + 'render_template', 'template'] + + +class RelationContext(dict): + """ + Base class for a context generator that gets relation data from juju. + + Subclasses must provide the attributes `name`, which is the name of the + interface of interest, `interface`, which is the type of the interface of + interest, and `required_keys`, which is the set of keys required for the + relation to be considered complete. The data for all interfaces matching + the `name` attribute that are complete will used to populate the dictionary + values (see `get_data`, below). + + The generated context will be namespaced under the relation :attr:`name`, + to prevent potential naming conflicts. + + :param str name: Override the relation :attr:`name`, since it can vary from charm to charm + :param list additional_required_keys: Extend the list of :attr:`required_keys` + """ + name = None + interface = None + + def __init__(self, name=None, additional_required_keys=None): + if not hasattr(self, 'required_keys'): + self.required_keys = [] + + if name is not None: + self.name = name + if additional_required_keys: + self.required_keys.extend(additional_required_keys) + self.get_data() + + def __bool__(self): + """ + Returns True if all of the required_keys are available. + """ + return self.is_ready() + + __nonzero__ = __bool__ + + def __repr__(self): + return super(RelationContext, self).__repr__() + + def is_ready(self): + """ + Returns True if all of the `required_keys` are available from any units. + """ + ready = len(self.get(self.name, [])) > 0 + if not ready: + hookenv.log('Incomplete relation: {}'.format(self.__class__.__name__), hookenv.DEBUG) + return ready + + def _is_ready(self, unit_data): + """ + Helper method that tests a set of relation data and returns True if + all of the `required_keys` are present. + """ + return set(unit_data.keys()).issuperset(set(self.required_keys)) + + def get_data(self): + """ + Retrieve the relation data for each unit involved in a relation and, + if complete, store it in a list under `self[self.name]`. This + is automatically called when the RelationContext is instantiated. + + The units are sorted lexographically first by the service ID, then by + the unit ID. Thus, if an interface has two other services, 'db:1' + and 'db:2', with 'db:1' having two units, 'wordpress/0' and 'wordpress/1', + and 'db:2' having one unit, 'mediawiki/0', all of which have a complete + set of data, the relation data for the units will be stored in the + order: 'wordpress/0', 'wordpress/1', 'mediawiki/0'. + + If you only care about a single unit on the relation, you can just + access it as `{{ interface[0]['key'] }}`. However, if you can at all + support multiple units on a relation, you should iterate over the list, + like:: + + {% for unit in interface -%} + {{ unit['key'] }}{% if not loop.last %},{% endif %} + {%- endfor %} + + Note that since all sets of relation data from all related services and + units are in a single list, if you need to know which service or unit a + set of data came from, you'll need to extend this class to preserve + that information. + """ + if not hookenv.relation_ids(self.name): + return + + ns = self.setdefault(self.name, []) + for rid in sorted(hookenv.relation_ids(self.name)): + for unit in sorted(hookenv.related_units(rid)): + reldata = hookenv.relation_get(rid=rid, unit=unit) + if self._is_ready(reldata): + ns.append(reldata) + + def provide_data(self): + """ + Return data to be relation_set for this interface. + """ + return {} + + +class MysqlRelation(RelationContext): + """ + Relation context for the `mysql` interface. + + :param str name: Override the relation :attr:`name`, since it can vary from charm to charm + :param list additional_required_keys: Extend the list of :attr:`required_keys` + """ + name = 'db' + interface = 'mysql' + + def __init__(self, *args, **kwargs): + self.required_keys = ['host', 'user', 'password', 'database'] + RelationContext.__init__(self, *args, **kwargs) + + +class HttpRelation(RelationContext): + """ + Relation context for the `http` interface. + + :param str name: Override the relation :attr:`name`, since it can vary from charm to charm + :param list additional_required_keys: Extend the list of :attr:`required_keys` + """ + name = 'website' + interface = 'http' + + def __init__(self, *args, **kwargs): + self.required_keys = ['host', 'port'] + RelationContext.__init__(self, *args, **kwargs) + + def provide_data(self): + return { + 'host': hookenv.unit_get('private-address'), + 'port': 80, + } + + +class RequiredConfig(dict): + """ + Data context that loads config options with one or more mandatory options. + + Once the required options have been changed from their default values, all + config options will be available, namespaced under `config` to prevent + potential naming conflicts (for example, between a config option and a + relation property). + + :param list *args: List of options that must be changed from their default values. + """ + + def __init__(self, *args): + self.required_options = args + self['config'] = hookenv.config() + with open(os.path.join(hookenv.charm_dir(), 'config.yaml')) as fp: + self.config = yaml.load(fp).get('options', {}) + + def __bool__(self): + for option in self.required_options: + if option not in self['config']: + return False + current_value = self['config'][option] + default_value = self.config[option].get('default') + if current_value == default_value: + return False + if current_value in (None, '') and default_value in (None, ''): + return False + return True + + def __nonzero__(self): + return self.__bool__() + + +class StoredContext(dict): + """ + A data context that always returns the data that it was first created with. + + This is useful to do a one-time generation of things like passwords, that + will thereafter use the same value that was originally generated, instead + of generating a new value each time it is run. + """ + def __init__(self, file_name, config_data): + """ + If the file exists, populate `self` with the data from the file. + Otherwise, populate with the given data and persist it to the file. + """ + if os.path.exists(file_name): + self.update(self.read_context(file_name)) + else: + self.store_context(file_name, config_data) + self.update(config_data) + + def store_context(self, file_name, config_data): + if not os.path.isabs(file_name): + file_name = os.path.join(hookenv.charm_dir(), file_name) + with open(file_name, 'w') as file_stream: + os.fchmod(file_stream.fileno(), 0o600) + yaml.dump(config_data, file_stream) + + def read_context(self, file_name): + if not os.path.isabs(file_name): + file_name = os.path.join(hookenv.charm_dir(), file_name) + with open(file_name, 'r') as file_stream: + data = yaml.load(file_stream) + if not data: + raise OSError("%s is empty" % file_name) + return data + + +class TemplateCallback(ManagerCallback): + """ + Callback class that will render a Jinja2 template, for use as a ready + action. + + :param str source: The template source file, relative to + `$CHARM_DIR/templates` + + :param str target: The target to write the rendered template to (or None) + :param str owner: The owner of the rendered file + :param str group: The group of the rendered file + :param int perms: The permissions of the rendered file + :param partial on_change_action: functools partial to be executed when + rendered file changes + :param jinja2 loader template_loader: A jinja2 template loader + + :return str: The rendered template + """ + def __init__(self, source, target, + owner='root', group='root', perms=0o444, + on_change_action=None, template_loader=None): + self.source = source + self.target = target + self.owner = owner + self.group = group + self.perms = perms + self.on_change_action = on_change_action + self.template_loader = template_loader + + def __call__(self, manager, service_name, event_name): + pre_checksum = '' + if self.on_change_action and os.path.isfile(self.target): + pre_checksum = host.file_hash(self.target) + service = manager.get_service(service_name) + context = {'ctx': {}} + for ctx in service.get('required_data', []): + context.update(ctx) + context['ctx'].update(ctx) + + result = templating.render(self.source, self.target, context, + self.owner, self.group, self.perms, + template_loader=self.template_loader) + if self.on_change_action: + if pre_checksum == host.file_hash(self.target): + hookenv.log( + 'No change detected: {}'.format(self.target), + hookenv.DEBUG) + else: + self.on_change_action() + + return result + + +# Convenience aliases for templates +render_template = template = TemplateCallback |