installers/charm/mysqld-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         "mysql_host": lambda value, _: isinstance(value, str) and len(value) > 0,
  72         "mysql_port": lambda value, _: isinstance(value, str) and int(value) > 0,
  73         "mysql_user": lambda value, _: isinstance(value, str) and len(value) > 0,
  74         "mysql_password": lambda value, _: isinstance(value, str) and len(value) > 0,
  75         "mysql_root_password": lambda value, _: isinstance(value, str)
  76         and len(value) > 0,
  77     }
  78     problems = []
  79
  80     for key, validator in config_validators.items():
  81         valid = validator(config_data.get(key), config_data)
  82
  83         if not valid:
  84             problems.append(key)
  85
  86     for key, validator in relation_validators.items():
  87         valid = validator(relation_data.get(key), relation_data)
  88
  89         if not valid:
  90             problems.append(key)
  91
  92     if len(problems) > 0:
  93         raise ValueError("Errors found in: {}".format(", ".join(problems)))
  94
  95     return True
  96
  97
  98 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
  99     """Generate pod ports details.
 100
 101     Args:
 102         port (int): port to expose.
 103
 104     Returns:
 105         List[Dict[str, Any]]: pod port details.
 106     """
 107     return [{"name": "mysqld-exporter", "containerPort": port, "protocol": "TCP"}]
 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         "DATA_SOURCE_NAME": "root:{mysql_root_password}@({mysql_host}:{mysql_port})/".format(
 124             **relation_state
 125         )
 126     }
 127
 128     return envconfig
 129
 130
 131 def _make_pod_ingress_resources(
 132     config: Dict[str, Any], app_name: str, port: int
 133 ) -> List[Dict[str, Any]]:
 134     """Generate pod ingress resources.
 135
 136     Args:
 137         config (Dict[str, Any]): configuration information.
 138         app_name (str): application name.
 139         port (int): port to expose.
 140
 141     Returns:
 142         List[Dict[str, Any]]: pod ingress resources.
 143     """
 144     site_url = config.get("site_url")
 145
 146     if not site_url:
 147         return
 148
 149     parsed = urlparse(site_url)
 150
 151     if not parsed.scheme.startswith("http"):
 152         return
 153
 154     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 155
 156     annotations = {}
 157
 158     if ingress_whitelist_source_range:
 159         annotations[
 160             "nginx.ingress.kubernetes.io/whitelist-source-range"
 161         ] = ingress_whitelist_source_range
 162
 163     ingress_spec_tls = None
 164
 165     if parsed.scheme == "https":
 166         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 167         tls_secret_name = config["tls_secret_name"]
 168         if tls_secret_name:
 169             ingress_spec_tls[0]["secretName"] = tls_secret_name
 170     else:
 171         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 172
 173     ingress = {
 174         "name": "{}-ingress".format(app_name),
 175         "annotations": annotations,
 176         "spec": {
 177             "rules": [
 178                 {
 179                     "host": parsed.hostname,
 180                     "http": {
 181                         "paths": [
 182                             {
 183                                 "path": "/",
 184                                 "backend": {
 185                                     "serviceName": app_name,
 186                                     "servicePort": port,
 187                                 },
 188                             }
 189                         ]
 190                     },
 191                 }
 192             ]
 193         },
 194     }
 195     if ingress_spec_tls:
 196         ingress["spec"]["tls"] = ingress_spec_tls
 197
 198     return [ingress]
 199
 200
 201 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 202     """Generate readiness probe.
 203
 204     Args:
 205         port (int): service port.
 206
 207     Returns:
 208         Dict[str, Any]: readiness probe.
 209     """
 210     return {
 211         "httpGet": {
 212             "path": "/api/health",
 213             "port": port,
 214         },
 215         "initialDelaySeconds": 10,
 216         "periodSeconds": 10,
 217         "timeoutSeconds": 5,
 218         "successThreshold": 1,
 219         "failureThreshold": 3,
 220     }
 221
 222
 223 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 224     """Generate liveness probe.
 225
 226     Args:
 227         port (int): service port.
 228
 229     Returns:
 230         Dict[str, Any]: liveness probe.
 231     """
 232     return {
 233         "httpGet": {
 234             "path": "/api/health",
 235             "port": port,
 236         },
 237         "initialDelaySeconds": 60,
 238         "timeoutSeconds": 30,
 239         "failureThreshold": 10,
 240     }
 241
 242
 243 def make_pod_spec(
 244     image_info: Dict[str, str],
 245     config: Dict[str, Any],
 246     relation_state: Dict[str, Any],
 247     app_name: str = "mysqld-exporter",
 248     port: int = 9104,
 249 ) -> Dict[str, Any]:
 250     """Generate the pod spec information.
 251
 252     Args:
 253         image_info (Dict[str, str]): Object provided by
 254                                      OCIImageResource("image").fetch().
 255         config (Dict[str, Any]): Configuration information.
 256         relation_state (Dict[str, Any]): Relation state information.
 257         app_name (str, optional): Application name. Defaults to "ro".
 258         port (int, optional): Port for the container. Defaults to 9090.
 259
 260     Returns:
 261         Dict[str, Any]: Pod spec dictionary for the charm.
 262     """
 263     if not image_info:
 264         return None
 265
 266     _validate_data(config, relation_state)
 267
 268     ports = _make_pod_ports(port)
 269     env_config = _make_pod_envconfig(config, relation_state)
 270     readiness_probe = _make_readiness_probe(port)
 271     liveness_probe = _make_liveness_probe(port)
 272     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 273
 274     return {
 275         "version": 3,
 276         "containers": [
 277             {
 278                 "name": app_name,
 279                 "imageDetails": image_info,
 280                 "imagePullPolicy": "Always",
 281                 "ports": ports,
 282                 "envConfig": env_config,
 283                 "kubernetes": {
 284                     "readinessProbe": readiness_probe,
 285                     "livenessProbe": liveness_probe,
 286                 },
 287             }
 288         ],
 289         "kubernetesResources": {
 290             "ingressResources": ingress_resources or [],
 291         },
 292     }