installers/charm/prometheus-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 [
 106         {"name": "prometheus-kafka-exporter", "containerPort": port, "protocol": "TCP"}
 107     ]
 108
 109
 110 def _make_pod_envconfig(
 111     config: Dict[str, Any], relation_state: Dict[str, Any]
 112 ) -> Dict[str, Any]:
 113     """Generate pod environment configuration.
 114
 115     Args:
 116         config (Dict[str, Any]): configuration information.
 117         relation_state (Dict[str, Any]): relation state information.
 118
 119     Returns:
 120         Dict[str, Any]: pod environment configuration.
 121     """
 122     envconfig = {}
 123
 124     return envconfig
 125
 126
 127 def _make_pod_ingress_resources(
 128     config: Dict[str, Any], app_name: str, port: int
 129 ) -> List[Dict[str, Any]]:
 130     """Generate pod ingress resources.
 131
 132     Args:
 133         config (Dict[str, Any]): configuration information.
 134         app_name (str): application name.
 135         port (int): port to expose.
 136
 137     Returns:
 138         List[Dict[str, Any]]: pod ingress resources.
 139     """
 140     site_url = config.get("site_url")
 141
 142     if not site_url:
 143         return
 144
 145     parsed = urlparse(site_url)
 146
 147     if not parsed.scheme.startswith("http"):
 148         return
 149
 150     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 151
 152     annotations = {}
 153
 154     if ingress_whitelist_source_range:
 155         annotations[
 156             "nginx.ingress.kubernetes.io/whitelist-source-range"
 157         ] = ingress_whitelist_source_range
 158
 159     ingress_spec_tls = None
 160
 161     if parsed.scheme == "https":
 162         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 163         tls_secret_name = config["tls_secret_name"]
 164         if tls_secret_name:
 165             ingress_spec_tls[0]["secretName"] = tls_secret_name
 166     else:
 167         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 168
 169     ingress = {
 170         "name": "{}-ingress".format(app_name),
 171         "annotations": annotations,
 172         "spec": {
 173             "rules": [
 174                 {
 175                     "host": parsed.hostname,
 176                     "http": {
 177                         "paths": [
 178                             {
 179                                 "path": "/",
 180                                 "backend": {
 181                                     "serviceName": app_name,
 182                                     "servicePort": port,
 183                                 },
 184                             }
 185                         ]
 186                     },
 187                 }
 188             ]
 189         },
 190     }
 191     if ingress_spec_tls:
 192         ingress["spec"]["tls"] = ingress_spec_tls
 193
 194     return [ingress]
 195
 196
 197 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 198     """Generate readiness probe.
 199
 200     Args:
 201         port (int): service port.
 202
 203     Returns:
 204         Dict[str, Any]: readiness probe.
 205     """
 206     return {
 207         "httpGet": {
 208             "path": "/api/health",
 209             "port": port,
 210         },
 211         "initialDelaySeconds": 10,
 212         "periodSeconds": 10,
 213         "timeoutSeconds": 5,
 214         "successThreshold": 1,
 215         "failureThreshold": 3,
 216     }
 217
 218
 219 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 220     """Generate liveness probe.
 221
 222     Args:
 223         port (int): service port.
 224
 225     Returns:
 226         Dict[str, Any]: liveness probe.
 227     """
 228     return {
 229         "httpGet": {
 230             "path": "/api/health",
 231             "port": port,
 232         },
 233         "initialDelaySeconds": 60,
 234         "timeoutSeconds": 30,
 235         "failureThreshold": 10,
 236     }
 237
 238
 239 def _make_pod_command(relation: Dict[str, Any]) -> List[str]:
 240     """Generate the startup command.
 241
 242     Args:
 243         relation (Dict[str, Any]): Relation information.
 244
 245     Returns:
 246         List[str]: command to startup the process.
 247     """
 248     command = [
 249         "kafka-exporter",
 250         "--kafka.server={}:{}".format(
 251             relation.get("kafka_host"), relation.get("kafka_port")
 252         ),
 253     ]
 254
 255     return command
 256
 257
 258 def make_pod_spec(
 259     image_info: Dict[str, str],
 260     config: Dict[str, Any],
 261     relation_state: Dict[str, Any],
 262     app_name: str = "prometheus-kafka-exporter",
 263     port: int = 9308,
 264 ) -> Dict[str, Any]:
 265     """Generate the pod spec information.
 266
 267     Args:
 268         image_info (Dict[str, str]): Object provided by
 269                                      OCIImageResource("image").fetch().
 270         config (Dict[str, Any]): Configuration information.
 271         relation_state (Dict[str, Any]): Relation state information.
 272         app_name (str, optional): Application name. Defaults to "ro".
 273         port (int, optional): Port for the container. Defaults to 9090.
 274
 275     Returns:
 276         Dict[str, Any]: Pod spec dictionary for the charm.
 277     """
 278     if not image_info:
 279         return None
 280
 281     _validate_data(config, relation_state)
 282
 283     ports = _make_pod_ports(port)
 284     env_config = _make_pod_envconfig(config, relation_state)
 285     readiness_probe = _make_readiness_probe(port)
 286     liveness_probe = _make_liveness_probe(port)
 287     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 288     command = _make_pod_command(relation_state)
 289
 290     return {
 291         "version": 3,
 292         "containers": [
 293             {
 294                 "name": app_name,
 295                 "imageDetails": image_info,
 296                 "imagePullPolicy": "Always",
 297                 "ports": ports,
 298                 "envConfig": env_config,
 299                 "command": command,
 300                 "kubernetes": {
 301                     "readinessProbe": readiness_probe,
 302                     "livenessProbe": liveness_probe,
 303                 },
 304             }
 305         ],
 306         "kubernetesResources": {
 307             "ingressResources": ingress_resources or [],
 308         },
 309     }