installers/charm/pla/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, Optional
  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     database_commonkey: str
  47     mongodb_uri: Optional[str]
  48     log_level: str
  49     image_pull_policy: str
  50
  51     @validator("log_level")
  52     def validate_log_level(cls, v):
  53         if v not in {"INFO", "DEBUG"}:
  54             raise ValueError("value must be INFO or DEBUG")
  55         return v
  56
  57     @validator("mongodb_uri")
  58     def validate_mongodb_uri(cls, v):
  59         if v and not v.startswith("mongodb://"):
  60             raise ValueError("mongodb_uri is not properly formed")
  61         return v
  62
  63     @validator("image_pull_policy")
  64     def validate_image_pull_policy(cls, v):
  65         values = {
  66             "always": "Always",
  67             "ifnotpresent": "IfNotPresent",
  68             "never": "Never",
  69         }
  70         v = v.lower()
  71         if v not in values.keys():
  72             raise ValueError("value must be always, ifnotpresent or never")
  73         return values[v]
  74
  75
  76 class PlaCharm(CharmedOsmBase):
  77     def __init__(self, *args) -> NoReturn:
  78         super().__init__(*args, oci_image="image")
  79
  80         self.kafka_client = KafkaClient(self, "kafka")
  81         self.framework.observe(self.on["kafka"].relation_changed, self.configure_pod)
  82         self.framework.observe(self.on["kafka"].relation_broken, self.configure_pod)
  83
  84         self.mongodb_client = MongoClient(self, "mongodb")
  85         self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
  86         self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
  87
  88     def _check_missing_dependencies(self, config: ConfigModel):
  89         missing_relations = []
  90
  91         if self.kafka_client.is_missing_data_in_unit():
  92             missing_relations.append("kafka")
  93         if not config.mongodb_uri and self.mongodb_client.is_missing_data_in_unit():
  94             missing_relations.append("mongodb")
  95
  96         if missing_relations:
  97             raise RelationsMissing(missing_relations)
  98
  99     def build_pod_spec(self, image_info):
 100         # Validate config
 101         config = ConfigModel(**dict(self.config))
 102
 103         if config.mongodb_uri and not self.mongodb_client.is_missing_data_in_unit():
 104             raise Exception("Mongodb data cannot be provided via config and relation")
 105
 106         # Check relations
 107         self._check_missing_dependencies(config)
 108
 109         # Create Builder for the PodSpec
 110         pod_spec_builder = PodSpecV3Builder()
 111
 112         # Build Container
 113         container_builder = ContainerV3Builder(
 114             self.app.name, image_info, config.image_pull_policy
 115         )
 116         container_builder.add_port(name=self.app.name, port=PORT)
 117         container_builder.add_envs(
 118             {
 119                 # General configuration
 120                 "ALLOW_ANONYMOUS_LOGIN": "yes",
 121                 "OSMPLA_GLOBAL_LOG_LEVEL": config.log_level,
 122                 # Kafka configuration
 123                 "OSMPLA_MESSAGE_DRIVER": "kafka",
 124                 "OSMPLA_MESSAGE_HOST": self.kafka_client.host,
 125                 "OSMPLA_MESSAGE_PORT": self.kafka_client.port,
 126                 # Database configuration
 127                 "OSMPLA_DATABASE_DRIVER": "mongo",
 128                 "OSMPLA_DATABASE_URI": config.mongodb_uri
 129                 or self.mongodb_client.connection_string,
 130                 "OSMPLA_DATABASE_COMMONKEY": config.database_commonkey,
 131             }
 132         )
 133
 134         container = container_builder.build()
 135
 136         # Add container to pod spec
 137         pod_spec_builder.add_container(container)
 138
 139         return pod_spec_builder.build()
 140
 141
 142 if __name__ == "__main__":
 143     main(PlaCharm)