installers/charm/prometheus/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_max_file_size(max_file_size: int, site_url: str) -> bool:
  32     """Validate max_file_size.
  33
  34     Args:
  35         max_file_size (int): maximum file size allowed.
  36         site_url (str): endpoint url.
  37
  38     Returns:
  39         bool: True if valid, false otherwise.
  40     """
  41     if not site_url:
  42         return True
  43
  44     parsed = urlparse(site_url)
  45
  46     if not parsed.scheme.startswith("http"):
  47         return True
  48
  49     if max_file_size is None:
  50         return False
  51
  52     return max_file_size >= 0
  53
  54
  55 def _validate_ip_network(network: str) -> bool:
  56     """Validate IP network.
  57
  58     Args:
  59         network (str): IP network range.
  60
  61     Returns:
  62         bool: True if valid, false otherwise.
  63     """
  64     if not network:
  65         return True
  66
  67     try:
  68         ip_network(network)
  69     except ValueError:
  70         return False
  71
  72     return True
  73
  74
  75 def _validate_data(config_data: Dict[str, Any], relation_data: Dict[str, Any]) -> bool:
  76     """Validates passed information.
  77
  78     Args:
  79         config_data (Dict[str, Any]): configuration information.
  80         relation_data (Dict[str, Any]): relation information
  81
  82     Raises:
  83         ValueError: when config and/or relation data is not valid.
  84     """
  85     config_validators = {
  86         "web_subpath": lambda value, _: isinstance(value, str) and len(value) > 0,
  87         "default_target": lambda value, _: isinstance(value, str),
  88         "site_url": lambda value, _: isinstance(value, str)
  89         if value is not None
  90         else True,
  91         "max_file_size": lambda value, values: _validate_max_file_size(
  92             value, values.get("site_url")
  93         ),
  94         "ingress_whitelist_source_range": lambda value, _: _validate_ip_network(value),
  95         "tls_secret_name": lambda value, _: isinstance(value, str)
  96         if value is not None
  97         else True,
  98     }
  99     relation_validators = {}
 100     problems = []
 101
 102     for key, validator in config_validators.items():
 103         valid = validator(config_data.get(key), config_data)
 104
 105         if not valid:
 106             problems.append(key)
 107
 108     for key, validator in relation_validators.items():
 109         valid = validator(relation_data.get(key), relation_data)
 110
 111         if not valid:
 112             problems.append(key)
 113
 114     if len(problems) > 0:
 115         raise ValueError("Errors found in: {}".format(", ".join(problems)))
 116
 117     return True
 118
 119
 120 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
 121     """Generate pod ports details.
 122
 123     Args:
 124         port (int): port to expose.
 125
 126     Returns:
 127         List[Dict[str, Any]]: pod port details.
 128     """
 129     return [{"name": "prometheus", "containerPort": port, "protocol": "TCP"}]
 130
 131
 132 def _make_pod_envconfig(
 133     config: Dict[str, Any], relation_state: Dict[str, Any]
 134 ) -> Dict[str, Any]:
 135     """Generate pod environment configuration.
 136
 137     Args:
 138         config (Dict[str, Any]): configuration information.
 139         relation_state (Dict[str, Any]): relation state information.
 140
 141     Returns:
 142         Dict[str, Any]: pod environment configuration.
 143     """
 144     envconfig = {}
 145
 146     return envconfig
 147
 148
 149 def _make_pod_ingress_resources(
 150     config: Dict[str, Any], app_name: str, port: int
 151 ) -> List[Dict[str, Any]]:
 152     """Generate pod ingress resources.
 153
 154     Args:
 155         config (Dict[str, Any]): configuration information.
 156         app_name (str): application name.
 157         port (int): port to expose.
 158
 159     Returns:
 160         List[Dict[str, Any]]: pod ingress resources.
 161     """
 162     site_url = config.get("site_url")
 163
 164     if not site_url:
 165         return
 166
 167     parsed = urlparse(site_url)
 168
 169     if not parsed.scheme.startswith("http"):
 170         return
 171
 172     max_file_size = config["max_file_size"]
 173     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 174
 175     annotations = {
 176         "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
 177             str(max_file_size) + "m" if max_file_size > 0 else max_file_size
 178         ),
 179     }
 180
 181     if ingress_whitelist_source_range:
 182         annotations[
 183             "nginx.ingress.kubernetes.io/whitelist-source-range"
 184         ] = ingress_whitelist_source_range
 185
 186     ingress_spec_tls = None
 187
 188     if parsed.scheme == "https":
 189         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 190         tls_secret_name = config["tls_secret_name"]
 191         if tls_secret_name:
 192             ingress_spec_tls[0]["secretName"] = tls_secret_name
 193     else:
 194         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 195
 196     ingress = {
 197         "name": "{}-ingress".format(app_name),
 198         "annotations": annotations,
 199         "spec": {
 200             "rules": [
 201                 {
 202                     "host": parsed.hostname,
 203                     "http": {
 204                         "paths": [
 205                             {
 206                                 "path": "/",
 207                                 "backend": {
 208                                     "serviceName": app_name,
 209                                     "servicePort": port,
 210                                 },
 211                             }
 212                         ]
 213                     },
 214                 }
 215             ]
 216         },
 217     }
 218     if ingress_spec_tls:
 219         ingress["spec"]["tls"] = ingress_spec_tls
 220
 221     return [ingress]
 222
 223
 224 def _make_pod_files(config: Dict[str, Any]) -> List[Dict[str, Any]]:
 225     """Generating ConfigMap information
 226
 227     Args:
 228         config (Dict[str, Any]): configuration information.
 229
 230     Returns:
 231         List[Dict[str, Any]]: ConfigMap information.
 232     """
 233     files = [
 234         {
 235             "name": "config",
 236             "mountPath": "/etc/prometheus",
 237             "files": [
 238                 {
 239                     "path": "prometheus.yml",
 240                     "content": (
 241                         "global:"
 242                         "  scrape_interval: 15s"
 243                         "  evaluation_interval: 15s"
 244                         "alerting:"
 245                         "  alertmanagers:"
 246                         "    - static_configs:"
 247                         "        - targets:"
 248                         "rule_files:"
 249                         "scrape_configs:"
 250                         "  - job_name: 'prometheus'"
 251                         "    static_configs:"
 252                         "      - targets: [{}]".format(config["default_target"])
 253                     ),
 254                 }
 255             ],
 256         }
 257     ]
 258
 259     return files
 260
 261
 262 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 263     """Generate readiness probe.
 264
 265     Args:
 266         port (int): service port.
 267
 268     Returns:
 269         Dict[str, Any]: readiness probe.
 270     """
 271     return {
 272         "httpGet": {
 273             "path": "/-/ready",
 274             "port": port,
 275         },
 276         "initialDelaySeconds": 10,
 277         "timeoutSeconds": 30,
 278     }
 279
 280
 281 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 282     """Generate liveness probe.
 283
 284     Args:
 285         port (int): service port.
 286
 287     Returns:
 288         Dict[str, Any]: liveness probe.
 289     """
 290     return {
 291         "httpGet": {
 292             "path": "/-/healthy",
 293             "port": port,
 294         },
 295         "initialDelaySeconds": 30,
 296         "periodSeconds": 30,
 297     }
 298
 299
 300 def _make_pod_command(config: Dict[str, Any], port: int) -> List[str]:
 301     """Generate the startup command.
 302
 303     Args:
 304         config (Dict[str, Any]): Configuration information.
 305         port (int): port.
 306
 307     Returns:
 308         List[str]: command to startup the process.
 309     """
 310     return [
 311         "sh",
 312         "-c",
 313         "/bin/prometheus",
 314         "--config.file=/etc/prometheus/prometheus.yml",
 315         "--storage.tsdb.path=/prometheus",
 316         "--web.console.libraries=/usr/share/prometheus/console_libraries",
 317         "--web.console.templates=/usr/share/prometheus/consoles",
 318         "--web.route-prefix={}".format(config.get("web_subpath")),
 319         "--web.external-url=http://localhost:{}{}".format(
 320             port, config.get("web_subpath")
 321         ),
 322     ]
 323
 324
 325 def make_pod_spec(
 326     image_info: Dict[str, str],
 327     config: Dict[str, Any],
 328     relation_state: Dict[str, Any],
 329     app_name: str = "prometheus",
 330     port: int = 9090,
 331 ) -> Dict[str, Any]:
 332     """Generate the pod spec information.
 333
 334     Args:
 335         image_info (Dict[str, str]): Object provided by
 336             OCIImageResource("image").fetch().
 337         config (Dict[str, Any]): Configuration information.
 338         relation_state (Dict[str, Any]): Relation state information.
 339         app_name (str, optional): Application name. Defaults to "ro".
 340         port (int, optional): Port for the container. Defaults to 9090.
 341
 342     Returns:
 343         Dict[str, Any]: Pod spec dictionary for the charm.
 344     """
 345     if not image_info:
 346         return None
 347
 348     _validate_data(config, relation_state)
 349
 350     ports = _make_pod_ports(port)
 351     env_config = _make_pod_envconfig(config, relation_state)
 352     files = _make_pod_files(config)
 353     readiness_probe = _make_readiness_probe(port)
 354     liveness_probe = _make_liveness_probe(port)
 355     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 356     command = _make_pod_command(config, port)
 357
 358     return {
 359         "version": 3,
 360         "containers": [
 361             {
 362                 "name": app_name,
 363                 "imageDetails": image_info,
 364                 "imagePullPolicy": "Always",
 365                 "ports": ports,
 366                 "envConfig": env_config,
 367                 "volumeConfig": files,
 368                 "command": command,
 369                 "kubernetes": {
 370                     "readinessProbe": readiness_probe,
 371                     "livenessProbe": liveness_probe,
 372                 },
 373             }
 374         ],
 375         "kubernetesResources": {
 376             "ingressResources": ingress_resources or [],
 377         },
 378     }