installers/charm/pol/src/pod_spec.py

   1 #!/usr/bin/env python3
   2 # Copyright 2020 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 import logging
  24 from typing import Any, Dict, List, NoReturn
  25
  26 logger = logging.getLogger(__name__)
  27
  28
  29 def _validate_data(
  30     config_data: Dict[str, Any], relation_data: Dict[str, Any]
  31 ) -> NoReturn:
  32     """Validate input data.
  33
  34     Args:
  35         config_data (Dict[str, Any]): configuration data.
  36         relation_data (Dict[str, Any]): relation data.
  37     """
  38     config_validators = {
  39         "log_level": lambda value, _: isinstance(value, str)
  40         and value in ("INFO", "DEBUG"),
  41     }
  42     relation_validators = {
  43         "message_host": lambda value, _: isinstance(value, str) and len(value) > 0,
  44         "message_port": lambda value, _: isinstance(value, int) and value > 0,
  45         "database_uri": lambda value, _: isinstance(value, str)
  46         and value.startswith("mongodb://"),
  47     }
  48     problems = []
  49
  50     for key, validator in config_validators.items():
  51         valid = validator(config_data.get(key), config_data)
  52
  53         if not valid:
  54             problems.append(key)
  55
  56     for key, validator in relation_validators.items():
  57         valid = validator(relation_data.get(key), relation_data)
  58
  59         if not valid:
  60             problems.append(key)
  61
  62     if len(problems) > 0:
  63         raise ValueError("Errors found in: {}".format(", ".join(problems)))
  64
  65
  66 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
  67     """Generate pod ports details.
  68
  69     Args:
  70         port (int): port to expose.
  71
  72     Returns:
  73         List[Dict[str, Any]]: pod port details.
  74     """
  75     return [{"name": "pol", "containerPort": port, "protocol": "TCP"}]
  76
  77
  78 def _make_pod_envconfig(
  79     config: Dict[str, Any], relation_state: Dict[str, Any]
  80 ) -> Dict[str, Any]:
  81     """Generate pod environment configuration.
  82
  83     Args:
  84         config (Dict[str, Any]): configuration information.
  85         relation_state (Dict[str, Any]): relation state information.
  86
  87     Returns:
  88         Dict[str, Any]: pod environment configuration.
  89     """
  90     envconfig = {
  91         # General configuration
  92         "ALLOW_ANONYMOUS_LOGIN": "yes",
  93         "OSMPOL_GLOBAL_LOGLEVEL": config["log_level"],
  94         # Kafka configuration
  95         "OSMPOL_MESSAGE_HOST": relation_state["message_host"],
  96         "OSMPOL_MESSAGE_DRIVER": "kafka",
  97         "OSMPOL_MESSAGE_PORT": relation_state["message_port"],
  98         # Database configuration
  99         "OSMPOL_DATABASE_DRIVER": "mongo",
 100         "OSMPOL_DATABASE_URI": relation_state["database_uri"],
 101     }
 102
 103     return envconfig
 104
 105
 106 def _make_startup_probe() -> Dict[str, Any]:
 107     """Generate startup probe.
 108
 109     Returns:
 110         Dict[str, Any]: startup probe.
 111     """
 112     return {
 113         "exec": {"command": ["/usr/bin/pgrep", "python3"]},
 114         "initialDelaySeconds": 60,
 115         "timeoutSeconds": 5,
 116     }
 117
 118
 119 def _make_readiness_probe() -> Dict[str, Any]:
 120     """Generate readiness probe.
 121
 122     Returns:
 123         Dict[str, Any]: readiness probe.
 124     """
 125     return {
 126         "exec": {
 127             "command": ["sh", "-c", "osm-pol-healthcheck || exit 1"],
 128         },
 129         "periodSeconds": 10,
 130         "timeoutSeconds": 5,
 131         "successThreshold": 1,
 132         "failureThreshold": 3,
 133     }
 134
 135
 136 def _make_liveness_probe() -> Dict[str, Any]:
 137     """Generate liveness probe.
 138
 139     Returns:
 140         Dict[str, Any]: liveness probe.
 141     """
 142     return {
 143         "exec": {
 144             "command": ["sh", "-c", "osm-pol-healthcheck || exit 1"],
 145         },
 146         "initialDelaySeconds": 45,
 147         "periodSeconds": 10,
 148         "timeoutSeconds": 5,
 149         "successThreshold": 1,
 150         "failureThreshold": 3,
 151     }
 152
 153
 154 def make_pod_spec(
 155     image_info: Dict[str, str],
 156     config: Dict[str, Any],
 157     relation_state: Dict[str, Any],
 158     app_name: str = "pol",
 159     port: int = 80,
 160 ) -> Dict[str, Any]:
 161     """Generate the pod spec information.
 162
 163     Args:
 164         image_info (Dict[str, str]): Object provided by
 165                                      OCIImageResource("image").fetch().
 166         config (Dict[str, Any]): Configuration information.
 167         relation_state (Dict[str, Any]): Relation state information.
 168         app_name (str, optional): Application name. Defaults to "pol".
 169         port (int, optional): Port for the container. Defaults to 80.
 170
 171     Returns:
 172         Dict[str, Any]: Pod spec dictionary for the charm.
 173     """
 174     if not image_info:
 175         return None
 176
 177     _validate_data(config, relation_state)
 178
 179     ports = _make_pod_ports(port)
 180     env_config = _make_pod_envconfig(config, relation_state)
 181
 182     return {
 183         "version": 3,
 184         "containers": [
 185             {
 186                 "name": app_name,
 187                 "imageDetails": image_info,
 188                 "imagePullPolicy": "Always",
 189                 "ports": ports,
 190                 "envConfig": env_config,
 191             }
 192         ],
 193         "kubernetesResources": {
 194             "ingressResources": [],
 195         },
 196     }