installers/charm/prometheus-mongodb-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         "mongodb_connection_string": lambda value, _: (
  72             isinstance(value, str) and value.startswith("mongodb://")
  73         )
  74     }
  75     problems = []
  76
  77     for key, validator in config_validators.items():
  78         valid = validator(config_data.get(key), config_data)
  79
  80         if not valid:
  81             problems.append(key)
  82
  83     for key, validator in relation_validators.items():
  84         valid = validator(relation_data.get(key), relation_data)
  85
  86         if not valid:
  87             problems.append(key)
  88
  89     if len(problems) > 0:
  90         raise ValueError("Errors found in: {}".format(", ".join(problems)))
  91
  92     return True
  93
  94
  95 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
  96     """Generate pod ports details.
  97
  98     Args:
  99         port (int): port to expose.
 100
 101     Returns:
 102         List[Dict[str, Any]]: pod port details.
 103     """
 104     return [
 105         {
 106             "name": "prometheus-mongodb-exporter",
 107             "containerPort": port,
 108             "protocol": "TCP",
 109         }
 110     ]
 111
 112
 113 def _make_pod_envconfig(
 114     config: Dict[str, Any], relation_state: Dict[str, Any]
 115 ) -> Dict[str, Any]:
 116     """Generate pod environment configuration.
 117
 118     Args:
 119         config (Dict[str, Any]): configuration information.
 120         relation_state (Dict[str, Any]): relation state information.
 121
 122     Returns:
 123         Dict[str, Any]: pod environment configuration.
 124     """
 125     envconfig = {}
 126
 127     return envconfig
 128
 129
 130 def _make_pod_ingress_resources(
 131     config: Dict[str, Any], app_name: str, port: int
 132 ) -> List[Dict[str, Any]]:
 133     """Generate pod ingress resources.
 134
 135     Args:
 136         config (Dict[str, Any]): configuration information.
 137         app_name (str): application name.
 138         port (int): port to expose.
 139
 140     Returns:
 141         List[Dict[str, Any]]: pod ingress resources.
 142     """
 143     site_url = config.get("site_url")
 144
 145     if not site_url:
 146         return
 147
 148     parsed = urlparse(site_url)
 149
 150     if not parsed.scheme.startswith("http"):
 151         return
 152
 153     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 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     ingress_spec_tls = None
 162
 163     if parsed.scheme == "https":
 164         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 165         tls_secret_name = config["tls_secret_name"]
 166         if tls_secret_name:
 167             ingress_spec_tls[0]["secretName"] = tls_secret_name
 168     else:
 169         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 170
 171     ingress = {
 172         "name": "{}-ingress".format(app_name),
 173         "annotations": annotations,
 174         "spec": {
 175             "rules": [
 176                 {
 177                     "host": parsed.hostname,
 178                     "http": {
 179                         "paths": [
 180                             {
 181                                 "path": "/",
 182                                 "backend": {
 183                                     "serviceName": app_name,
 184                                     "servicePort": port,
 185                                 },
 186                             }
 187                         ]
 188                     },
 189                 }
 190             ]
 191         },
 192     }
 193     if ingress_spec_tls:
 194         ingress["spec"]["tls"] = ingress_spec_tls
 195
 196     return [ingress]
 197
 198
 199 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 200     """Generate readiness probe.
 201
 202     Args:
 203         port (int): service port.
 204
 205     Returns:
 206         Dict[str, Any]: readiness probe.
 207     """
 208     return {
 209         "httpGet": {
 210             "path": "/api/health",
 211             "port": port,
 212         },
 213         "initialDelaySeconds": 10,
 214         "periodSeconds": 10,
 215         "timeoutSeconds": 5,
 216         "successThreshold": 1,
 217         "failureThreshold": 3,
 218     }
 219
 220
 221 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 222     """Generate liveness probe.
 223
 224     Args:
 225         port (int): service port.
 226
 227     Returns:
 228         Dict[str, Any]: liveness probe.
 229     """
 230     return {
 231         "httpGet": {
 232             "path": "/api/health",
 233             "port": port,
 234         },
 235         "initialDelaySeconds": 60,
 236         "timeoutSeconds": 30,
 237         "failureThreshold": 10,
 238     }
 239
 240
 241 def _make_pod_command(relation: Dict[str, Any]) -> List[str]:
 242     """Generate the startup command.
 243
 244     Args:
 245         relation (Dict[str, Any]): Relation information.
 246
 247     Returns:
 248         List[str]: command to startup the process.
 249     """
 250     command = [
 251         "mongodb_exporter_linux_amd64/mongodb_exporter",
 252         "--mongodbdsn={}".format(relation.get("mongodb_connection_string")),
 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-mongodb-exporter",
 263     port: int = 9216,
 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     }