| #!/usr/bin/env python3 |
| # Copyright 2022 Canonical Ltd. |
| # |
| # 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. |
| # |
| # For those usages not covered by the Apache License, Version 2.0 please |
| # contact: legal@canonical.com |
| # |
| # To get in touch with the maintainers, please contact: |
| # osm-charmers@lists.launchpad.net |
| # |
| # |
| # Learn more at: https://juju.is/docs/sdk |
| |
| """OSM POL charm. |
| |
| See more: https://charmhub.io/osm |
| """ |
| |
| import logging |
| from typing import Any, Dict |
| |
| from charms.data_platform_libs.v0.data_interfaces import DatabaseRequires |
| from charms.kafka_k8s.v0.kafka import KafkaEvents, KafkaRequires |
| from charms.osm_libs.v0.utils import ( |
| CharmError, |
| DebugMode, |
| HostPath, |
| check_container_ready, |
| check_service_active, |
| ) |
| from ops.charm import ActionEvent, CharmBase |
| from ops.framework import StoredState |
| from ops.main import main |
| from ops.model import ActiveStatus, Container |
| |
| from legacy_interfaces import MysqlClient |
| |
| HOSTPATHS = [ |
| HostPath( |
| config="pol-hostpath", |
| container_path="/usr/lib/python3/dist-packages/osm_policy_module", |
| ), |
| HostPath( |
| config="common-hostpath", |
| container_path="/usr/lib/python3/dist-packages/osm_common", |
| ), |
| ] |
| |
| logger = logging.getLogger(__name__) |
| |
| |
| class OsmPolCharm(CharmBase): |
| """OSM POL Kubernetes sidecar charm.""" |
| |
| on = KafkaEvents() |
| _stored = StoredState() |
| container_name = "pol" |
| service_name = "pol" |
| |
| def __init__(self, *args): |
| super().__init__(*args) |
| |
| self.kafka = KafkaRequires(self) |
| self.mongodb_client = DatabaseRequires(self, "mongodb", database_name="osm") |
| self.mysql_client = MysqlClient(self, "mysql") |
| self._observe_charm_events() |
| self.container: Container = self.unit.get_container(self.container_name) |
| self.debug_mode = DebugMode(self, self._stored, self.container, HOSTPATHS) |
| |
| # --------------------------------------------------------------------------- |
| # Handlers for Charm Events |
| # --------------------------------------------------------------------------- |
| |
| def _on_config_changed(self, _) -> None: |
| """Handler for the config-changed event.""" |
| try: |
| self._validate_config() |
| self._check_relations() |
| # Check if the container is ready. |
| # Eventually it will become ready after the first pebble-ready event. |
| check_container_ready(self.container) |
| |
| if not self.debug_mode.started: |
| self._configure_service(self.container) |
| # Update charm status |
| self._on_update_status() |
| except CharmError as e: |
| logger.debug(e.message) |
| self.unit.status = e.status |
| |
| def _on_update_status(self, _=None) -> None: |
| """Handler for the update-status event.""" |
| try: |
| self._validate_config() |
| self._check_relations() |
| check_container_ready(self.container) |
| if self.debug_mode.started: |
| return |
| check_service_active(self.container, self.service_name) |
| self.unit.status = ActiveStatus() |
| except CharmError as e: |
| logger.debug(e.message) |
| self.unit.status = e.status |
| |
| def _on_required_relation_broken(self, _) -> None: |
| """Handler for the kafka-broken event.""" |
| # Check Pebble has started in the container |
| try: |
| check_container_ready(self.container) |
| check_service_active(self.container, self.service_name) |
| self.container.stop(self.container_name) |
| except CharmError: |
| pass |
| self._on_update_status() |
| |
| def _on_get_debug_mode_information_action(self, event: ActionEvent) -> None: |
| """Handler for the get-debug-mode-information action event.""" |
| if not self.debug_mode.started: |
| event.fail("debug-mode has not started. Hint: juju config pol debug-mode=true") |
| return |
| |
| debug_info = {"command": self.debug_mode.command, "password": self.debug_mode.password} |
| event.set_results(debug_info) |
| |
| # --------------------------------------------------------------------------- |
| # Validation and configuration and more |
| # --------------------------------------------------------------------------- |
| |
| def _observe_charm_events(self) -> None: |
| event_handler_mapping = { |
| # Core lifecycle events |
| self.on.pol_pebble_ready: self._on_config_changed, |
| self.on.config_changed: self._on_config_changed, |
| self.on.update_status: self._on_update_status, |
| # Relation events |
| self.on.kafka_available: self._on_config_changed, |
| self.on["kafka"].relation_broken: self._on_required_relation_broken, |
| self.on["mysql"].relation_changed: self._on_config_changed, |
| self.on["mysql"].relation_broken: self._on_config_changed, |
| self.mongodb_client.on.database_created: self._on_config_changed, |
| self.on["mongodb"].relation_broken: self._on_required_relation_broken, |
| # Action events |
| self.on.get_debug_mode_information_action: self._on_get_debug_mode_information_action, |
| } |
| |
| for event, handler in event_handler_mapping.items(): |
| self.framework.observe(event, handler) |
| |
| def _is_database_available(self) -> bool: |
| try: |
| return self.mongodb_client.is_resource_created() |
| except KeyError: |
| return False |
| |
| def _validate_config(self) -> None: |
| """Validate charm configuration. |
| |
| Raises: |
| CharmError: if charm configuration is invalid. |
| """ |
| logger.debug("validating charm config") |
| |
| def _check_relations(self) -> None: |
| """Validate charm relations. |
| |
| Raises: |
| CharmError: if charm configuration is invalid. |
| """ |
| logger.debug("check for missing relations") |
| missing_relations = [] |
| |
| if not self.kafka.host or not self.kafka.port: |
| missing_relations.append("kafka") |
| if not self._is_database_available(): |
| missing_relations.append("mongodb") |
| if not self.config.get("mysql-uri") and self.mysql_client.is_missing_data_in_unit(): |
| missing_relations.append("mysql") |
| |
| if missing_relations: |
| relations_str = ", ".join(missing_relations) |
| one_relation_missing = len(missing_relations) == 1 |
| error_msg = f'need {relations_str} relation{"" if one_relation_missing else "s"}' |
| logger.warning(error_msg) |
| raise CharmError(error_msg) |
| |
| def _configure_service(self, container: Container) -> None: |
| """Add Pebble layer with the pol service.""" |
| logger.debug(f"configuring {self.app.name} service") |
| container.add_layer("pol", self._get_layer(), combine=True) |
| container.replan() |
| |
| def _get_layer(self) -> Dict[str, Any]: |
| """Get layer for Pebble.""" |
| return { |
| "summary": "pol layer", |
| "description": "pebble config layer for pol", |
| "services": { |
| self.service_name: { |
| "override": "replace", |
| "summary": "pol service", |
| "command": "/bin/bash scripts/start.sh", |
| "startup": "enabled", |
| "user": "appuser", |
| "group": "appuser", |
| "environment": { |
| # General configuration |
| "OSMPOL_GLOBAL_LOGLEVEL": self.config["log-level"], |
| # Kafka configuration |
| "OSMPOL_MESSAGE_HOST": self.kafka.host, |
| "OSMPOL_MESSAGE_PORT": self.kafka.port, |
| "OSMPOL_MESSAGE_DRIVER": "kafka", |
| # Database Mongodb configuration |
| "OSMPOL_DATABASE_DRIVER": "mongo", |
| "OSMPOL_DATABASE_URI": self._get_mongodb_uri(), |
| # Database MySQL configuration |
| "OSMPOL_SQL_DATABASE_URI": self._get_mysql_uri(), |
| }, |
| } |
| }, |
| } |
| |
| def _get_mysql_uri(self): |
| return self.config.get("mysql-uri") or self.mysql_client.get_root_uri("pol") |
| |
| def _get_mongodb_uri(self): |
| return list(self.mongodb_client.fetch_relation_data().values())[0]["uris"] |
| |
| |
| if __name__ == "__main__": # pragma: no cover |
| main(OsmPolCharm) |