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
  31 from opslib.osm.charm import CharmedOsmBase, RelationsMissing
  32
  33 from opslib.osm.pod import (
  34     ContainerV3Builder,
  35     PodSpecV3Builder,
  36 )
  37
  38 from opslib.osm.validator import (
  39     ModelValidator,
  40     validator,
  41 )
  42
  43 from opslib.osm.interfaces.kafka import KafkaClient
  44 from opslib.osm.interfaces.mongo import MongoClient
  45
  46
  47 logger = logging.getLogger(__name__)
  48
  49 PORT = 9999
  50
  51
  52 class ConfigModel(ModelValidator):
  53     log_level: str
  54
  55     @validator("log_level")
  56     def validate_log_level(cls, v):
  57         if v not in {"INFO", "DEBUG"}:
  58             raise ValueError("value must be INFO or DEBUG")
  59         return v
  60
  61
  62 class PolCharm(CharmedOsmBase):
  63     def __init__(self, *args) -> NoReturn:
  64         super().__init__(*args, oci_image="image")
  65
  66         self.kafka_client = KafkaClient(self, "kafka")
  67         self.framework.observe(self.on["kafka"].relation_changed, self.configure_pod)
  68         self.framework.observe(self.on["kafka"].relation_broken, self.configure_pod)
  69
  70         self.mongodb_client = MongoClient(self, "mongodb")
  71         self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
  72         self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
  73
  74     def _check_missing_dependencies(self, config: ConfigModel):
  75         missing_relations = []
  76
  77         if self.kafka_client.is_missing_data_in_unit():
  78             missing_relations.append("kafka")
  79         if self.mongodb_client.is_missing_data_in_unit():
  80             missing_relations.append("mongodb")
  81
  82         if missing_relations:
  83             raise RelationsMissing(missing_relations)
  84
  85     def build_pod_spec(self, image_info):
  86         # Validate config
  87         config = ConfigModel(**dict(self.config))
  88         # Check relations
  89         self._check_missing_dependencies(config)
  90         # Create Builder for the PodSpec
  91         pod_spec_builder = PodSpecV3Builder()
  92         # Build Container
  93         container_builder = ContainerV3Builder(self.app.name, image_info)
  94         container_builder.add_port(name=self.app.name, port=PORT)
  95         container_builder.add_envs(
  96             {
  97                 # General configuration
  98                 "ALLOW_ANONYMOUS_LOGIN": "yes",
  99                 "OSMPOL_GLOBAL_LOGLEVEL": config.log_level,
 100                 # Kafka configuration
 101                 "OSMPOL_MESSAGE_DRIVER": "kafka",
 102                 "OSMPOL_MESSAGE_HOST": self.kafka_client.host,
 103                 "OSMPOL_MESSAGE_PORT": self.kafka_client.port,
 104                 # Database configuration
 105                 "OSMPOL_DATABASE_DRIVER": "mongo",
 106                 "OSMPOL_DATABASE_URI": self.mongodb_client.connection_string,
 107             }
 108         )
 109
 110         container = container_builder.build()
 111         # Add container to pod spec
 112         pod_spec_builder.add_container(container)
 113         return pod_spec_builder.build()
 114
 115
 116 if __name__ == "__main__":
 117     main(PolCharm)