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 from ipaddress import ip_network
  24 import logging
  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         "cluster_issuer": lambda value, _: isinstance(value, str)
  66         if value is not None
  67         else True,
  68         "ingress_whitelist_source_range": lambda value, _: _validate_ip_network(value),
  69         "tls_secret_name": lambda value, _: isinstance(value, str)
  70         if value is not None
  71         else True,
  72     }
  73     relation_validators = {
  74         "kafka_host": lambda value, _: isinstance(value, str) and len(value) > 0,
  75         "kafka_port": lambda value, _: isinstance(value, str)
  76         and len(value) > 0
  77         and int(value) > 0,
  78     }
  79     problems = []
  80
  81     for key, validator in config_validators.items():
  82         valid = validator(config_data.get(key), config_data)
  83
  84         if not valid:
  85             problems.append(key)
  86
  87     for key, validator in relation_validators.items():
  88         valid = validator(relation_data.get(key), relation_data)
  89
  90         if not valid:
  91             problems.append(key)
  92
  93     if len(problems) > 0:
  94         raise ValueError("Errors found in: {}".format(", ".join(problems)))
  95
  96     return True
  97
  98
  99 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
 100     """Generate pod ports details.
 101
 102     Args:
 103         port (int): port to expose.
 104
 105     Returns:
 106         List[Dict[str, Any]]: pod port details.
 107     """
 108     return [{"name": "kafka-exporter", "containerPort": port, "protocol": "TCP"}]
 109
 110
 111 def _make_pod_envconfig(
 112     config: Dict[str, Any], relation_state: Dict[str, Any]
 113 ) -> Dict[str, Any]:
 114     """Generate pod environment configuration.
 115
 116     Args:
 117         config (Dict[str, Any]): configuration information.
 118         relation_state (Dict[str, Any]): relation state information.
 119
 120     Returns:
 121         Dict[str, Any]: pod environment configuration.
 122     """
 123     envconfig = {}
 124
 125     return envconfig
 126
 127
 128 def _make_pod_ingress_resources(
 129     config: Dict[str, Any], app_name: str, port: int
 130 ) -> List[Dict[str, Any]]:
 131     """Generate pod ingress resources.
 132
 133     Args:
 134         config (Dict[str, Any]): configuration information.
 135         app_name (str): application name.
 136         port (int): port to expose.
 137
 138     Returns:
 139         List[Dict[str, Any]]: pod ingress resources.
 140     """
 141     site_url = config.get("site_url")
 142
 143     if not site_url:
 144         return
 145
 146     parsed = urlparse(site_url)
 147
 148     if not parsed.scheme.startswith("http"):
 149         return
 150
 151     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 152     cluster_issuer = config["cluster_issuer"]
 153
 154     annotations = {}
 155
 156     if ingress_whitelist_source_range:
 157         annotations[
 158             "nginx.ingress.kubernetes.io/whitelist-source-range"
 159         ] = ingress_whitelist_source_range
 160
 161     if cluster_issuer:
 162         annotations["cert-manager.io/cluster-issuer"] = cluster_issuer
 163
 164     ingress_spec_tls = None
 165
 166     if parsed.scheme == "https":
 167         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 168         tls_secret_name = config["tls_secret_name"]
 169         if tls_secret_name:
 170             ingress_spec_tls[0]["secretName"] = tls_secret_name
 171     else:
 172         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 173
 174     ingress = {
 175         "name": "{}-ingress".format(app_name),
 176         "annotations": annotations,
 177         "spec": {
 178             "rules": [
 179                 {
 180                     "host": parsed.hostname,
 181                     "http": {
 182                         "paths": [
 183                             {
 184                                 "path": "/",
 185                                 "backend": {
 186                                     "serviceName": app_name,
 187                                     "servicePort": port,
 188                                 },
 189                             }
 190                         ]
 191                     },
 192                 }
 193             ]
 194         },
 195     }
 196     if ingress_spec_tls:
 197         ingress["spec"]["tls"] = ingress_spec_tls
 198
 199     return [ingress]
 200
 201
 202 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 203     """Generate readiness probe.
 204
 205     Args:
 206         port (int): service port.
 207
 208     Returns:
 209         Dict[str, Any]: readiness probe.
 210     """
 211     return {
 212         "httpGet": {
 213             "path": "/api/health",
 214             "port": port,
 215         },
 216         "initialDelaySeconds": 10,
 217         "periodSeconds": 10,
 218         "timeoutSeconds": 5,
 219         "successThreshold": 1,
 220         "failureThreshold": 3,
 221     }
 222
 223
 224 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 225     """Generate liveness probe.
 226
 227     Args:
 228         port (int): service port.
 229
 230     Returns:
 231         Dict[str, Any]: liveness probe.
 232     """
 233     return {
 234         "httpGet": {
 235             "path": "/api/health",
 236             "port": port,
 237         },
 238         "initialDelaySeconds": 60,
 239         "timeoutSeconds": 30,
 240         "failureThreshold": 10,
 241     }
 242
 243
 244 def _make_pod_command(relation: Dict[str, Any]) -> List[str]:
 245     """Generate the startup command.
 246
 247     Args:
 248         relation (Dict[str, Any]): Relation information.
 249
 250     Returns:
 251         List[str]: command to startup the process.
 252     """
 253     command = [
 254         "kafka_exporter",
 255         "--kafka.server={}:{}".format(
 256             relation.get("kafka_host"), relation.get("kafka_port")
 257         ),
 258     ]
 259
 260     return command
 261
 262
 263 def make_pod_spec(
 264     image_info: Dict[str, str],
 265     config: Dict[str, Any],
 266     relation_state: Dict[str, Any],
 267     app_name: str = "kafka-exporter",
 268     port: int = 9308,
 269 ) -> Dict[str, Any]:
 270     """Generate the pod spec information.
 271
 272     Args:
 273         image_info (Dict[str, str]): Object provided by
 274                                      OCIImageResource("image").fetch().
 275         config (Dict[str, Any]): Configuration information.
 276         relation_state (Dict[str, Any]): Relation state information.
 277         app_name (str, optional): Application name. Defaults to "ro".
 278         port (int, optional): Port for the container. Defaults to 9090.
 279
 280     Returns:
 281         Dict[str, Any]: Pod spec dictionary for the charm.
 282     """
 283     if not image_info:
 284         return None
 285
 286     _validate_data(config, relation_state)
 287
 288     ports = _make_pod_ports(port)
 289     env_config = _make_pod_envconfig(config, relation_state)
 290     readiness_probe = _make_readiness_probe(port)
 291     liveness_probe = _make_liveness_probe(port)
 292     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 293     command = _make_pod_command(relation_state)
 294
 295     return {
 296         "version": 3,
 297         "containers": [
 298             {
 299                 "name": app_name,
 300                 "imageDetails": image_info,
 301                 "imagePullPolicy": "Always",
 302                 "ports": ports,
 303                 "envConfig": env_config,
 304                 "command": command,
 305                 "kubernetes": {
 306                     "readinessProbe": readiness_probe,
 307                     "livenessProbe": liveness_probe,
 308                 },
 309             }
 310         ],
 311         "kubernetesResources": {
 312             "ingressResources": ingress_resources or [],
 313         },
 314     }