| #!/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 NG-UI charm. |
| |
| See more: https://charmhub.io/osm |
| """ |
| |
| import logging |
| import re |
| from typing import Any, Dict |
| |
| from charms.nginx_ingress_integrator.v0.ingress import IngressRequires |
| from charms.observability_libs.v1.kubernetes_service_patch import KubernetesServicePatch |
| from charms.osm_libs.v0.utils import ( |
| CharmError, |
| check_container_ready, |
| check_service_active, |
| ) |
| from charms.osm_nbi.v0.nbi import NbiRequires |
| from lightkube.models.core_v1 import ServicePort |
| from ops.charm import CharmBase |
| from ops.framework import StoredState |
| from ops.main import main |
| from ops.model import ActiveStatus, BlockedStatus, Container |
| |
| SERVICE_PORT = 80 |
| |
| logger = logging.getLogger(__name__) |
| |
| |
| class OsmNgUiCharm(CharmBase): |
| """OSM NG-UI Kubernetes sidecar charm.""" |
| |
| _stored = StoredState() |
| |
| def __init__(self, *args): |
| super().__init__(*args) |
| self.ingress = IngressRequires( |
| self, |
| { |
| "service-hostname": self.external_hostname, |
| "service-name": self.app.name, |
| "service-port": SERVICE_PORT, |
| }, |
| ) |
| self._observe_charm_events() |
| self._patch_k8s_service() |
| self._stored.set_default(default_site_patched=False) |
| self.nbi = NbiRequires(self) |
| self.container: Container = self.unit.get_container("ng-ui") |
| |
| @property |
| def external_hostname(self) -> str: |
| """External hostname property. |
| |
| Returns: |
| str: the external hostname from config. |
| If not set, return the ClusterIP service name. |
| """ |
| return self.config.get("external-hostname") or self.app.name |
| |
| # --------------------------------------------------------------------------- |
| # 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) |
| |
| self._configure_service(self.container) |
| self._update_ingress_config() |
| # 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._check_relations() |
| check_container_ready(self.container) |
| check_service_active(self.container, "ng-ui") |
| self.unit.status = ActiveStatus() |
| except CharmError as e: |
| logger.debug(e.message) |
| self.unit.status = e.status |
| |
| def _on_nbi_relation_broken(self, _) -> None: |
| """Handler for the nbi relation broken event.""" |
| # Check Pebble has started in the container |
| try: |
| check_container_ready(self.container) |
| check_service_active(self.container, "ng-ui") |
| self.container.stop("ng-ui") |
| self._stored.default_site_patched = False |
| except CharmError: |
| pass |
| finally: |
| self.unit.status = BlockedStatus("need nbi relation") |
| |
| # --------------------------------------------------------------------------- |
| # Validation and configuration and more |
| # --------------------------------------------------------------------------- |
| |
| def _patch_k8s_service(self) -> None: |
| port = ServicePort(SERVICE_PORT, name=f"{self.app.name}") |
| self.service_patcher = KubernetesServicePatch(self, [port]) |
| |
| def _observe_charm_events(self) -> None: |
| event_handler_mapping = { |
| # Core lifecycle events |
| self.on.ng_ui_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["nbi"].relation_changed: self._on_config_changed, |
| self.on["nbi"].relation_broken: self._on_nbi_relation_broken, |
| } |
| for event, handler in event_handler_mapping.items(): |
| self.framework.observe(event, handler) |
| |
| 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") |
| |
| if not self.nbi.host or not self.nbi.port: |
| raise CharmError("need nbi relation") |
| |
| def _update_ingress_config(self) -> None: |
| """Update ingress config in relation.""" |
| ingress_config = { |
| "service-hostname": self.external_hostname, |
| "max-body-size": self.config["max-body-size"], |
| } |
| if "tls-secret-name" in self.config: |
| ingress_config["tls-secret-name"] = self.config["tls-secret-name"] |
| logger.debug(f"updating ingress-config: {ingress_config}") |
| self.ingress.update_config(ingress_config) |
| |
| def _configure_service(self, container: Container) -> None: |
| """Add Pebble layer with the ng-ui service.""" |
| logger.debug(f"configuring {self.app.name} service") |
| self._patch_default_site(container) |
| container.add_layer("ng-ui", self._get_layer(), combine=True) |
| container.replan() |
| |
| def _get_layer(self) -> Dict[str, Any]: |
| """Get layer for Pebble.""" |
| return { |
| "summary": "ng-ui layer", |
| "description": "pebble config layer for ng-ui", |
| "services": { |
| "ng-ui": { |
| "override": "replace", |
| "summary": "ng-ui service", |
| "command": 'nginx -g "daemon off;"', |
| "startup": "enabled", |
| } |
| }, |
| } |
| |
| def _patch_default_site(self, container: Container) -> None: |
| max_body_size = self.config.get("max-body-size") |
| if ( |
| self._stored.default_site_patched |
| and max_body_size == self._stored.default_site_max_body_size |
| ): |
| return |
| default_site_config = container.pull("/etc/nginx/sites-available/default").read() |
| default_site_config = re.sub( |
| "client_max_body_size .*\n", |
| f"client_max_body_size {max_body_size}M;\n", |
| default_site_config, |
| ) |
| default_site_config = re.sub( |
| "proxy_pass .*\n", |
| f"proxy_pass http://{self.nbi.host}:{self.nbi.port};\n", |
| default_site_config, |
| ) |
| container.push("/etc/nginx/sites-available/default", default_site_config) |
| self._stored.default_site_patched = True |
| self._stored.default_site_max_body_size = max_body_size |
| |
| |
| if __name__ == "__main__": # pragma: no cover |
| main(OsmNgUiCharm) |