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 charms.kafka_k8s.v0.kafka import KafkaEvents, KafkaRequires
  30 from ops.main import main
  31 from opslib.osm.charm import CharmedOsmBase, RelationsMissing
  32 from opslib.osm.interfaces.mongo import MongoClient
  33 from opslib.osm.pod import (
  34     ContainerV3Builder,
  35     PodRestartPolicy,
  36     PodSpecV3Builder,
  37 )
  38 from opslib.osm.validator import ModelValidator, validator
  39
  40
  41 logger = logging.getLogger(__name__)
  42
  43 PORT = 9999
  44
  45
  46 class ConfigModel(ModelValidator):
  47     database_commonkey: str
  48     mongodb_uri: Optional[str]
  49     log_level: str
  50     image_pull_policy: str
  51     security_context: bool
  52
  53     @validator("log_level")
  54     def validate_log_level(cls, v):
  55         if v not in {"INFO", "DEBUG"}:
  56             raise ValueError("value must be INFO or DEBUG")
  57         return v
  58
  59     @validator("mongodb_uri")
  60     def validate_mongodb_uri(cls, v):
  61         if v and not v.startswith("mongodb://"):
  62             raise ValueError("mongodb_uri is not properly formed")
  63         return v
  64
  65     @validator("image_pull_policy")
  66     def validate_image_pull_policy(cls, v):
  67         values = {
  68             "always": "Always",
  69             "ifnotpresent": "IfNotPresent",
  70             "never": "Never",
  71         }
  72         v = v.lower()
  73         if v not in values.keys():
  74             raise ValueError("value must be always, ifnotpresent or never")
  75         return values[v]
  76
  77
  78 class PlaCharm(CharmedOsmBase):
  79     on = KafkaEvents()
  80
  81     def __init__(self, *args) -> NoReturn:
  82         super().__init__(*args, oci_image="image")
  83
  84         self.kafka = KafkaRequires(self)
  85         self.framework.observe(self.on.kafka_available, self.configure_pod)
  86         self.framework.observe(self.on.kafka_broken, self.configure_pod)
  87
  88         self.mongodb_client = MongoClient(self, "mongodb")
  89         self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
  90         self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
  91
  92     def _check_missing_dependencies(self, config: ConfigModel):
  93         missing_relations = []
  94
  95         if not self.kafka.host or not self.kafka.port:
  96             missing_relations.append("kafka")
  97         if not config.mongodb_uri and self.mongodb_client.is_missing_data_in_unit():
  98             missing_relations.append("mongodb")
  99
 100         if missing_relations:
 101             raise RelationsMissing(missing_relations)
 102
 103     def build_pod_spec(self, image_info):
 104         # Validate config
 105         config = ConfigModel(**dict(self.config))
 106
 107         if config.mongodb_uri and not self.mongodb_client.is_missing_data_in_unit():
 108             raise Exception("Mongodb data cannot be provided via config and relation")
 109
 110         # Check relations
 111         self._check_missing_dependencies(config)
 112
 113         # Create Builder for the PodSpec
 114         pod_spec_builder = PodSpecV3Builder(
 115             enable_security_context=config.security_context
 116         )
 117
 118         # Add secrets to the pod
 119         mongodb_secret_name = f"{self.app.name}-mongodb-secret"
 120         pod_spec_builder.add_secret(
 121             mongodb_secret_name,
 122             {
 123                 "uri": config.mongodb_uri or self.mongodb_client.connection_string,
 124                 "commonkey": config.database_commonkey,
 125             },
 126         )
 127
 128         # Build Container
 129         container_builder = ContainerV3Builder(
 130             self.app.name,
 131             image_info,
 132             config.image_pull_policy,
 133             run_as_non_root=config.security_context,
 134         )
 135         container_builder.add_port(name=self.app.name, port=PORT)
 136         container_builder.add_envs(
 137             {
 138                 # General configuration
 139                 "ALLOW_ANONYMOUS_LOGIN": "yes",
 140                 "OSMPLA_GLOBAL_LOG_LEVEL": config.log_level,
 141                 # Kafka configuration
 142                 "OSMPLA_MESSAGE_DRIVER": "kafka",
 143                 "OSMPLA_MESSAGE_HOST": self.kafka.host,
 144                 "OSMPLA_MESSAGE_PORT": self.kafka.port,
 145                 # Database configuration
 146                 "OSMPLA_DATABASE_DRIVER": "mongo",
 147             }
 148         )
 149
 150         container_builder.add_secret_envs(
 151             secret_name=mongodb_secret_name,
 152             envs={
 153                 "OSMPLA_DATABASE_URI": "uri",
 154                 "OSMPLA_DATABASE_COMMONKEY": "commonkey",
 155             },
 156         )
 157
 158         container = container_builder.build()
 159
 160         # Add Pod restart policy
 161         restart_policy = PodRestartPolicy()
 162         restart_policy.add_secrets(secret_names=(mongodb_secret_name,))
 163         pod_spec_builder.set_restart_policy(restart_policy)
 164
 165         # Add container to pod spec
 166         pod_spec_builder.add_container(container)
 167
 168         return pod_spec_builder.build()
 169
 170
 171 if __name__ == "__main__":
 172     main(PlaCharm)