installers/charm/osm-ro/src/charm.py

   1 #!/usr/bin/env python3
   2 # Copyright 2022 Canonical Ltd.
   3 #
   4 # Licensed under the Apache License, Version 2.0 (the "License"); you may
   5 # not use this file except in compliance with the License. You may obtain
   6 # a copy of the License at
   7 #
   8 #         http://www.apache.org/licenses/LICENSE-2.0
   9 #
  10 # Unless required by applicable law or agreed to in writing, software
  11 # distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  12 # WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  13 # License for the specific language governing permissions and limitations
  14 # under the License.
  15 #
  16 # For those usages not covered by the Apache License, Version 2.0 please
  17 # contact: legal@canonical.com
  18 #
  19 # To get in touch with the maintainers, please contact:
  20 # osm-charmers@lists.launchpad.net
  21 #
  22 #
  23 # Learn more at: https://juju.is/docs/sdk
  24
  25 """OSM RO charm.
  26
  27 See more: https://charmhub.io/osm
  28 """
  29
  30 import base64
  31 import logging
  32 from typing import Any, Dict
  33
  34 from charms.kafka_k8s.v0.kafka import KafkaEvents, KafkaRequires
  35 from charms.observability_libs.v1.kubernetes_service_patch import KubernetesServicePatch
  36 from charms.osm_libs.v0.utils import (
  37     CharmError,
  38     DebugMode,
  39     HostPath,
  40     check_container_ready,
  41     check_service_active,
  42 )
  43 from charms.osm_ro.v0.ro import RoProvides
  44 from lightkube.models.core_v1 import ServicePort
  45 from ops.charm import ActionEvent, CharmBase, RelationJoinedEvent
  46 from ops.framework import StoredState
  47 from ops.main import main
  48 from ops.model import ActiveStatus, Container
  49
  50 from legacy_interfaces import MongoClient
  51
  52 HOSTPATHS = [
  53     HostPath(
  54         config="ro-hostpath",
  55         container_path="/usr/lib/python3/dist-packages/osm_ro",
  56     ),
  57     HostPath(
  58         config="common-hostpath",
  59         container_path="/usr/lib/python3/dist-packages/osm_common",
  60     ),
  61 ]
  62 SERVICE_PORT = 9090
  63 USER = GROUP = "appuser"
  64
  65 logger = logging.getLogger(__name__)
  66
  67
  68 def decode(content: str):
  69     """Base64 decoding of a string."""
  70     return base64.b64decode(content.encode("utf-8")).decode("utf-8")
  71
  72
  73 class OsmRoCharm(CharmBase):
  74     """OSM RO Kubernetes sidecar charm."""
  75
  76     on = KafkaEvents()
  77     service_name = "ro"
  78     _stored = StoredState()
  79
  80     def __init__(self, *args):
  81         super().__init__(*args)
  82         self._stored.set_default(certificates=set())
  83         self.kafka = KafkaRequires(self)
  84         self.mongodb_client = MongoClient(self, "mongodb")
  85         self._observe_charm_events()
  86         self._patch_k8s_service()
  87         self.ro = RoProvides(self)
  88         self.container: Container = self.unit.get_container("ro")
  89         self.debug_mode = DebugMode(self, self._stored, self.container, HOSTPATHS)
  90
  91     # ---------------------------------------------------------------------------
  92     #   Handlers for Charm Events
  93     # ---------------------------------------------------------------------------
  94
  95     def _on_config_changed(self, _) -> None:
  96         """Handler for the config-changed event."""
  97         try:
  98             self._validate_config()
  99             self._check_relations()
 100             # Check if the container is ready.
 101             # Eventually it will become ready after the first pebble-ready event.
 102             check_container_ready(self.container)
 103
 104             self._configure_certificates()
 105             self._configure_service()
 106             self._update_ro_relation()
 107
 108             # Update charm status
 109             self._on_update_status()
 110         except CharmError as e:
 111             logger.debug(e.message)
 112             self.unit.status = e.status
 113
 114     def _on_update_status(self, _=None) -> None:
 115         """Handler for the update-status event."""
 116         try:
 117             self._validate_config()
 118             self._check_relations()
 119             check_container_ready(self.container)
 120             if self.debug_mode.started:
 121                 return
 122             check_service_active(self.container, self.service_name)
 123             self.unit.status = ActiveStatus()
 124         except CharmError as e:
 125             logger.debug(e.message)
 126             self.unit.status = e.status
 127
 128     def _on_required_relation_broken(self, _) -> None:
 129         """Handler for the kafka-broken event."""
 130         try:
 131             check_container_ready(self.container)
 132             check_service_active(self.container, "ro")
 133             self.container.stop("ro")
 134         except CharmError:
 135             pass
 136
 137         self._on_update_status()
 138
 139     def _update_ro_relation(self, event: RelationJoinedEvent = None) -> None:
 140         """Handler for the ro-relation-joined event."""
 141         try:
 142             if self.unit.is_leader():
 143                 check_container_ready(self.container)
 144                 check_service_active(self.container, "ro")
 145                 self.ro.set_host_info(
 146                     self.app.name, SERVICE_PORT, event.relation if event else None
 147                 )
 148         except CharmError as e:
 149             self.unit.status = e.status
 150
 151     def _on_get_debug_mode_information_action(self, event: ActionEvent) -> None:
 152         """Handler for the get-debug-mode-information action event."""
 153         if not self.debug_mode.started:
 154             event.fail(
 155                 f"debug-mode has not started. Hint: juju config {self.app.name} debug-mode=true"
 156             )
 157             return
 158
 159         debug_info = {"command": self.debug_mode.command, "password": self.debug_mode.password}
 160         event.set_results(debug_info)
 161
 162     # ---------------------------------------------------------------------------
 163     #   Validation and configuration and more
 164     # ---------------------------------------------------------------------------
 165
 166     def _patch_k8s_service(self) -> None:
 167         port = ServicePort(SERVICE_PORT, name=f"{self.app.name}")
 168         self.service_patcher = KubernetesServicePatch(self, [port])
 169
 170     def _observe_charm_events(self) -> None:
 171         event_handler_mapping = {
 172             # Core lifecycle events
 173             self.on.ro_pebble_ready: self._on_config_changed,
 174             self.on.config_changed: self._on_config_changed,
 175             self.on.update_status: self._on_update_status,
 176             # Relation events
 177             self.on.kafka_available: self._on_config_changed,
 178             self.on["kafka"].relation_broken: self._on_required_relation_broken,
 179             self.on["mongodb"].relation_changed: self._on_config_changed,
 180             self.on["mongodb"].relation_broken: self._on_required_relation_broken,
 181             self.on.ro_relation_joined: self._update_ro_relation,
 182             # Action events
 183             self.on.get_debug_mode_information_action: self._on_get_debug_mode_information_action,
 184         }
 185
 186         for event, handler in event_handler_mapping.items():
 187             self.framework.observe(event, handler)
 188
 189     def _validate_config(self) -> None:
 190         """Validate charm configuration.
 191
 192         Raises:
 193             CharmError: if charm configuration is invalid.
 194         """
 195         logger.debug("validating charm config")
 196         if self.config["log-level"].upper() not in [
 197             "TRACE",
 198             "DEBUG",
 199             "INFO",
 200             "WARN",
 201             "ERROR",
 202             "FATAL",
 203         ]:
 204             raise CharmError("invalid value for log-level option")
 205
 206     def _check_relations(self) -> None:
 207         """Validate charm relations.
 208
 209         Raises:
 210             CharmError: if charm configuration is invalid.
 211         """
 212         logger.debug("check for missing relations")
 213         missing_relations = []
 214
 215         if not self.kafka.host or not self.kafka.port:
 216             missing_relations.append("kafka")
 217         if self.mongodb_client.is_missing_data_in_unit():
 218             missing_relations.append("mongodb")
 219
 220         if missing_relations:
 221             relations_str = ", ".join(missing_relations)
 222             one_relation_missing = len(missing_relations) == 1
 223             error_msg = f'need {relations_str} relation{"" if one_relation_missing else "s"}'
 224             logger.warning(error_msg)
 225             raise CharmError(error_msg)
 226
 227     def _configure_certificates(self) -> None:
 228         """Push certificates to the RO container."""
 229         if not (certificate_config := self.config.get("certificates")):
 230             return
 231
 232         certificates_list = certificate_config.split(",")
 233         updated_certificates = set()
 234
 235         for certificate in certificates_list:
 236             if ":" not in certificate:
 237                 continue
 238             name, content = certificate.split(":")
 239             content = decode(content)
 240             self.container.push(
 241                 f"/certs/{name}",
 242                 content,
 243                 permissions=0o400,
 244                 make_dirs=True,
 245                 user=USER,
 246                 group=GROUP,
 247             )
 248             updated_certificates.add(name)
 249             self._stored.certificates.add(name)
 250             logger.info(f"certificate {name} pushed successfully")
 251
 252         stored_certificates = {c for c in self._stored.certificates}
 253         for certificate_to_remove in stored_certificates.difference(updated_certificates):
 254             self.container.remove_path(f"/certs/{certificate_to_remove}")
 255             self._stored.certificates.remove(certificate_to_remove)
 256             logger.info(f"certificate {certificate_to_remove} removed successfully")
 257
 258     def _configure_service(self) -> None:
 259         """Add Pebble layer with the ro service."""
 260         logger.debug(f"configuring {self.app.name} service")
 261         self.container.add_layer("ro", self._get_layer(), combine=True)
 262         self.container.replan()
 263
 264     def _get_layer(self) -> Dict[str, Any]:
 265         """Get layer for Pebble."""
 266         return {
 267             "summary": "ro layer",
 268             "description": "pebble config layer for ro",
 269             "services": {
 270                 "ro": {
 271                     "override": "replace",
 272                     "summary": "ro service",
 273                     "command": "python3 -u -m osm_ng_ro.ro_main",
 274                     "startup": "enabled",
 275                     "user": USER,
 276                     "group": GROUP,
 277                     "environment": {
 278                         # General configuration
 279                         "OSMRO_LOG_LEVEL": self.config["log-level"].upper(),
 280                         # Kafka configuration
 281                         "OSMRO_MESSAGE_HOST": self.kafka.host,
 282                         "OSMRO_MESSAGE_PORT": self.kafka.port,
 283                         "OSMRO_MESSAGE_DRIVER": "kafka",
 284                         # Database configuration
 285                         "OSMRO_DATABASE_DRIVER": "mongo",
 286                         "OSMRO_DATABASE_URI": self.mongodb_client.connection_string,
 287                         "OSMRO_DATABASE_COMMONKEY": self.config["database-commonkey"],
 288                         # Storage configuration
 289                         "OSMRO_STORAGE_DRIVER": "mongo",
 290                         "OSMRO_STORAGE_PATH": "/app/storage",
 291                         "OSMRO_STORAGE_COLLECTION": "files",
 292                         "OSMRO_STORAGE_URI": self.mongodb_client.connection_string,
 293                     },
 294                 }
 295             },
 296         }
 297
 298
 299 if __name__ == "__main__":  # pragma: no cover
 300     main(OsmRoCharm)