From 711967ae9639095ce41500bb0e6f80c8b80fab95 Mon Sep 17 00:00:00 2001 From: Stuart Mackie Date: Tue, 25 Jul 2017 10:37:57 -0700 Subject: Contrail charms Change-Id: I2d259d03f63fce38348b8384e26ac23e3fce44a8 Signed-off-by: Stuart Mackie --- .../hooks/charmhelpers/core/services/helpers.py | 290 +++++++++++++++++++++ 1 file changed, 290 insertions(+) create mode 100644 contrail-analytics/hooks/charmhelpers/core/services/helpers.py (limited to 'contrail-analytics/hooks/charmhelpers/core/services/helpers.py') 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 -- cgit 1.2.3-korg