installers/charm/kafka-exporter/src/pod_spec.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 import logging
  24 from ipaddress import ip_network
  25 from typing import Any, Dict, List
  26 from urllib.parse import urlparse
  27
  28 logger = logging.getLogger(__name__)
  29
  30
  31 def _validate_ip_network(network: str) -> bool:
  32     """Validate IP network.
  33
  34     Args:
  35         network (str): IP network range.
  36
  37     Returns:
  38         bool: True if valid, false otherwise.
  39     """
  40     if not network:
  41         return True
  42
  43     try:
  44         ip_network(network)
  45     except ValueError:
  46         return False
  47
  48     return True
  49
  50
  51 def _validate_data(config_data: Dict[str, Any], relation_data: Dict[str, Any]) -> bool:
  52     """Validates passed information.
  53
  54     Args:
  55         config_data (Dict[str, Any]): configuration information.
  56         relation_data (Dict[str, Any]): relation information
  57
  58     Raises:
  59         ValueError: when config and/or relation data is not valid.
  60     """
  61     config_validators = {
  62         "site_url": lambda value, _: isinstance(value, str)
  63         if value is not None
  64         else True,
  65         "ingress_whitelist_source_range": lambda value, _: _validate_ip_network(value),
  66         "tls_secret_name": lambda value, _: isinstance(value, str)
  67         if value is not None
  68         else True,
  69     }
  70     relation_validators = {
  71         "kafka_host": lambda value, _: isinstance(value, str) and len(value) > 0,
  72         "kafka_port": lambda value, _: isinstance(value, str)
  73         and len(value) > 0
  74         and int(value) > 0,
  75     }
  76     problems = []
  77
  78     for key, validator in config_validators.items():
  79         valid = validator(config_data.get(key), config_data)
  80
  81         if not valid:
  82             problems.append(key)
  83
  84     for key, validator in relation_validators.items():
  85         valid = validator(relation_data.get(key), relation_data)
  86
  87         if not valid:
  88             problems.append(key)
  89
  90     if len(problems) > 0:
  91         raise ValueError("Errors found in: {}".format(", ".join(problems)))
  92
  93     return True
  94
  95
  96 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
  97     """Generate pod ports details.
  98
  99     Args:
 100         port (int): port to expose.
 101
 102     Returns:
 103         List[Dict[str, Any]]: pod port details.
 104     """
 105     return [{"name": "kafka-exporter", "containerPort": port, "protocol": "TCP"}]
 106
 107
 108 def _make_pod_envconfig(
 109     config: Dict[str, Any], relation_state: Dict[str, Any]
 110 ) -> Dict[str, Any]:
 111     """Generate pod environment configuration.
 112
 113     Args:
 114         config (Dict[str, Any]): configuration information.
 115         relation_state (Dict[str, Any]): relation state information.
 116
 117     Returns:
 118         Dict[str, Any]: pod environment configuration.
 119     """
 120     envconfig = {}
 121
 122     return envconfig
 123
 124
 125 def _make_pod_ingress_resources(
 126     config: Dict[str, Any], app_name: str, port: int
 127 ) -> List[Dict[str, Any]]:
 128     """Generate pod ingress resources.
 129
 130     Args:
 131         config (Dict[str, Any]): configuration information.
 132         app_name (str): application name.
 133         port (int): port to expose.
 134
 135     Returns:
 136         List[Dict[str, Any]]: pod ingress resources.
 137     """
 138     site_url = config.get("site_url")
 139
 140     if not site_url:
 141         return
 142
 143     parsed = urlparse(site_url)
 144
 145     if not parsed.scheme.startswith("http"):
 146         return
 147
 148     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 149
 150     annotations = {}
 151
 152     if ingress_whitelist_source_range:
 153         annotations[
 154             "nginx.ingress.kubernetes.io/whitelist-source-range"
 155         ] = ingress_whitelist_source_range
 156
 157     ingress_spec_tls = None
 158
 159     if parsed.scheme == "https":
 160         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 161         tls_secret_name = config["tls_secret_name"]
 162         if tls_secret_name:
 163             ingress_spec_tls[0]["secretName"] = tls_secret_name
 164     else:
 165         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 166
 167     ingress = {
 168         "name": "{}-ingress".format(app_name),
 169         "annotations": annotations,
 170         "spec": {
 171             "rules": [
 172                 {
 173                     "host": parsed.hostname,
 174                     "http": {
 175                         "paths": [
 176                             {
 177                                 "path": "/",
 178                                 "backend": {
 179                                     "serviceName": app_name,
 180                                     "servicePort": port,
 181                                 },
 182                             }
 183                         ]
 184                     },
 185                 }
 186             ]
 187         },
 188     }
 189     if ingress_spec_tls:
 190         ingress["spec"]["tls"] = ingress_spec_tls
 191
 192     return [ingress]
 193
 194
 195 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 196     """Generate readiness probe.
 197
 198     Args:
 199         port (int): service port.
 200
 201     Returns:
 202         Dict[str, Any]: readiness probe.
 203     """
 204     return {
 205         "httpGet": {
 206             "path": "/api/health",
 207             "port": port,
 208         },
 209         "initialDelaySeconds": 10,
 210         "periodSeconds": 10,
 211         "timeoutSeconds": 5,
 212         "successThreshold": 1,
 213         "failureThreshold": 3,
 214     }
 215
 216
 217 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 218     """Generate liveness probe.
 219
 220     Args:
 221         port (int): service port.
 222
 223     Returns:
 224         Dict[str, Any]: liveness probe.
 225     """
 226     return {
 227         "httpGet": {
 228             "path": "/api/health",
 229             "port": port,
 230         },
 231         "initialDelaySeconds": 60,
 232         "timeoutSeconds": 30,
 233         "failureThreshold": 10,
 234     }
 235
 236
 237 def _make_pod_command(relation: Dict[str, Any]) -> List[str]:
 238     """Generate the startup command.
 239
 240     Args:
 241         relation (Dict[str, Any]): Relation information.
 242
 243     Returns:
 244         List[str]: command to startup the process.
 245     """
 246     command = [
 247         "kafka_exporter",
 248         "--kafka.server={}:{}".format(
 249             relation.get("kafka_host"), relation.get("kafka_port")
 250         ),
 251     ]
 252
 253     return command
 254
 255
 256 def make_pod_spec(
 257     image_info: Dict[str, str],
 258     config: Dict[str, Any],
 259     relation_state: Dict[str, Any],
 260     app_name: str = "kafka-exporter",
 261     port: int = 9308,
 262 ) -> Dict[str, Any]:
 263     """Generate the pod spec information.
 264
 265     Args:
 266         image_info (Dict[str, str]): Object provided by
 267                                      OCIImageResource("image").fetch().
 268         config (Dict[str, Any]): Configuration information.
 269         relation_state (Dict[str, Any]): Relation state information.
 270         app_name (str, optional): Application name. Defaults to "ro".
 271         port (int, optional): Port for the container. Defaults to 9090.
 272
 273     Returns:
 274         Dict[str, Any]: Pod spec dictionary for the charm.
 275     """
 276     if not image_info:
 277         return None
 278
 279     _validate_data(config, relation_state)
 280
 281     ports = _make_pod_ports(port)
 282     env_config = _make_pod_envconfig(config, relation_state)
 283     readiness_probe = _make_readiness_probe(port)
 284     liveness_probe = _make_liveness_probe(port)
 285     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 286     command = _make_pod_command(relation_state)
 287
 288     return {
 289         "version": 3,
 290         "containers": [
 291             {
 292                 "name": app_name,
 293                 "imageDetails": image_info,
 294                 "imagePullPolicy": "Always",
 295                 "ports": ports,
 296                 "envConfig": env_config,
 297                 "command": command,
 298                 "kubernetes": {
 299                     "readinessProbe": readiness_probe,
 300                     "livenessProbe": liveness_probe,
 301                 },
 302             }
 303         ],
 304         "kubernetesResources": {
 305             "ingressResources": ingress_resources or [],
 306         },
 307     }