installers/charm/pol/src/charm.py

   1 #!/usr/bin/env python3
   2 # Copyright 2021 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 # pylint: disable=E0213
  24
  25
  26 import logging
  27 from typing import NoReturn
  28
  29 from ops.main import main
  30 from opslib.osm.charm import CharmedOsmBase, RelationsMissing
  31 from opslib.osm.interfaces.kafka import KafkaClient
  32 from opslib.osm.interfaces.mongo import MongoClient
  33 from opslib.osm.pod import (
  34     ContainerV3Builder,
  35     PodSpecV3Builder,
  36 )
  37 from opslib.osm.validator import ModelValidator, validator
  38
  39
  40 logger = logging.getLogger(__name__)
  41
  42 PORT = 9999
  43
  44
  45 class ConfigModel(ModelValidator):
  46     log_level: str
  47
  48     @validator("log_level")
  49     def validate_log_level(cls, v):
  50         if v not in {"INFO", "DEBUG"}:
  51             raise ValueError("value must be INFO or DEBUG")
  52         return v
  53
  54
  55 class PolCharm(CharmedOsmBase):
  56     def __init__(self, *args) -> NoReturn:
  57         super().__init__(*args, oci_image="image")
  58
  59         self.kafka_client = KafkaClient(self, "kafka")
  60         self.framework.observe(self.on["kafka"].relation_changed, self.configure_pod)
  61         self.framework.observe(self.on["kafka"].relation_broken, self.configure_pod)
  62
  63         self.mongodb_client = MongoClient(self, "mongodb")
  64         self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
  65         self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
  66
  67     def _check_missing_dependencies(self, config: ConfigModel):
  68         missing_relations = []
  69
  70         if self.kafka_client.is_missing_data_in_unit():
  71             missing_relations.append("kafka")
  72         if self.mongodb_client.is_missing_data_in_unit():
  73             missing_relations.append("mongodb")
  74
  75         if missing_relations:
  76             raise RelationsMissing(missing_relations)
  77
  78     def build_pod_spec(self, image_info):
  79         # Validate config
  80         config = ConfigModel(**dict(self.config))
  81         # Check relations
  82         self._check_missing_dependencies(config)
  83         # Create Builder for the PodSpec
  84         pod_spec_builder = PodSpecV3Builder()
  85         # Build Container
  86         container_builder = ContainerV3Builder(self.app.name, image_info)
  87         container_builder.add_port(name=self.app.name, port=PORT)
  88         container_builder.add_envs(
  89             {
  90                 # General configuration
  91                 "ALLOW_ANONYMOUS_LOGIN": "yes",
  92                 "OSMPOL_GLOBAL_LOGLEVEL": config.log_level,
  93                 # Kafka configuration
  94                 "OSMPOL_MESSAGE_DRIVER": "kafka",
  95                 "OSMPOL_MESSAGE_HOST": self.kafka_client.host,
  96                 "OSMPOL_MESSAGE_PORT": self.kafka_client.port,
  97                 # Database configuration
  98                 "OSMPOL_DATABASE_DRIVER": "mongo",
  99                 "OSMPOL_DATABASE_URI": self.mongodb_client.connection_string,
 100             }
 101         )
 102
 103         container = container_builder.build()
 104         # Add container to pod spec
 105         pod_spec_builder.add_container(container)
 106         return pod_spec_builder.build()
 107
 108
 109 if __name__ == "__main__":
 110     main(PolCharm)