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         "enable_web_admin_api": lambda value, _: isinstance(value, bool),
  99     }
 100     relation_validators = {}
 101     problems = []
 102
 103     for key, validator in config_validators.items():
 104         valid = validator(config_data.get(key), config_data)
 105
 106         if not valid:
 107             problems.append(key)
 108
 109     for key, validator in relation_validators.items():
 110         valid = validator(relation_data.get(key), relation_data)
 111
 112         if not valid:
 113             problems.append(key)
 114
 115     if len(problems) > 0:
 116         raise ValueError("Errors found in: {}".format(", ".join(problems)))
 117
 118     return True
 119
 120
 121 def _make_pod_ports(port: int) -> List[Dict[str, Any]]:
 122     """Generate pod ports details.
 123
 124     Args:
 125         port (int): port to expose.
 126
 127     Returns:
 128         List[Dict[str, Any]]: pod port details.
 129     """
 130     return [{"name": "prometheus", "containerPort": port, "protocol": "TCP"}]
 131
 132
 133 def _make_pod_envconfig(
 134     config: Dict[str, Any], relation_state: Dict[str, Any]
 135 ) -> Dict[str, Any]:
 136     """Generate pod environment configuration.
 137
 138     Args:
 139         config (Dict[str, Any]): configuration information.
 140         relation_state (Dict[str, Any]): relation state information.
 141
 142     Returns:
 143         Dict[str, Any]: pod environment configuration.
 144     """
 145     envconfig = {}
 146
 147     return envconfig
 148
 149
 150 def _make_pod_ingress_resources(
 151     config: Dict[str, Any], app_name: str, port: int
 152 ) -> List[Dict[str, Any]]:
 153     """Generate pod ingress resources.
 154
 155     Args:
 156         config (Dict[str, Any]): configuration information.
 157         app_name (str): application name.
 158         port (int): port to expose.
 159
 160     Returns:
 161         List[Dict[str, Any]]: pod ingress resources.
 162     """
 163     site_url = config.get("site_url")
 164
 165     if not site_url:
 166         return
 167
 168     parsed = urlparse(site_url)
 169
 170     if not parsed.scheme.startswith("http"):
 171         return
 172
 173     max_file_size = config["max_file_size"]
 174     ingress_whitelist_source_range = config["ingress_whitelist_source_range"]
 175
 176     annotations = {
 177         "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
 178             str(max_file_size) + "m" if max_file_size > 0 else max_file_size
 179         ),
 180     }
 181
 182     if ingress_whitelist_source_range:
 183         annotations[
 184             "nginx.ingress.kubernetes.io/whitelist-source-range"
 185         ] = ingress_whitelist_source_range
 186
 187     ingress_spec_tls = None
 188
 189     if parsed.scheme == "https":
 190         ingress_spec_tls = [{"hosts": [parsed.hostname]}]
 191         tls_secret_name = config["tls_secret_name"]
 192         if tls_secret_name:
 193             ingress_spec_tls[0]["secretName"] = tls_secret_name
 194     else:
 195         annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 196
 197     ingress = {
 198         "name": "{}-ingress".format(app_name),
 199         "annotations": annotations,
 200         "spec": {
 201             "rules": [
 202                 {
 203                     "host": parsed.hostname,
 204                     "http": {
 205                         "paths": [
 206                             {
 207                                 "path": "/",
 208                                 "backend": {
 209                                     "serviceName": app_name,
 210                                     "servicePort": port,
 211                                 },
 212                             }
 213                         ]
 214                     },
 215                 }
 216             ]
 217         },
 218     }
 219     if ingress_spec_tls:
 220         ingress["spec"]["tls"] = ingress_spec_tls
 221
 222     return [ingress]
 223
 224
 225 def _make_pod_files(config: Dict[str, Any]) -> List[Dict[str, Any]]:
 226     """Generating ConfigMap information
 227
 228     Args:
 229         config (Dict[str, Any]): configuration information.
 230
 231     Returns:
 232         List[Dict[str, Any]]: ConfigMap information.
 233     """
 234     files = [
 235         {
 236             "name": "config",
 237             "mountPath": "/etc/prometheus",
 238             "files": [
 239                 {
 240                     "path": "prometheus.yml",
 241                     "content": (
 242                         "global:\n"
 243                         "  scrape_interval: 15s\n"
 244                         "  evaluation_interval: 15s\n"
 245                         "alerting:\n"
 246                         "  alertmanagers:\n"
 247                         "    - static_configs:\n"
 248                         "        - targets:\n"
 249                         "rule_files:\n"
 250                         "scrape_configs:\n"
 251                         "  - job_name: 'prometheus'\n"
 252                         "    static_configs:\n"
 253                         "      - targets: [{}]\n".format(config["default_target"])
 254                     ),
 255                 }
 256             ],
 257         }
 258     ]
 259
 260     return files
 261
 262
 263 def _make_readiness_probe(port: int) -> Dict[str, Any]:
 264     """Generate readiness probe.
 265
 266     Args:
 267         port (int): service port.
 268
 269     Returns:
 270         Dict[str, Any]: readiness probe.
 271     """
 272     return {
 273         "httpGet": {
 274             "path": "/-/ready",
 275             "port": port,
 276         },
 277         "initialDelaySeconds": 10,
 278         "timeoutSeconds": 30,
 279     }
 280
 281
 282 def _make_liveness_probe(port: int) -> Dict[str, Any]:
 283     """Generate liveness probe.
 284
 285     Args:
 286         port (int): service port.
 287
 288     Returns:
 289         Dict[str, Any]: liveness probe.
 290     """
 291     return {
 292         "httpGet": {
 293             "path": "/-/healthy",
 294             "port": port,
 295         },
 296         "initialDelaySeconds": 30,
 297         "periodSeconds": 30,
 298     }
 299
 300
 301 def _make_pod_command(config: Dict[str, Any], port: int) -> List[str]:
 302     """Generate the startup command.
 303
 304     Args:
 305         config (Dict[str, Any]): Configuration information.
 306         port (int): port.
 307
 308     Returns:
 309         List[str]: command to startup the process.
 310     """
 311     command = [
 312         "/bin/prometheus",
 313         "--config.file=/etc/prometheus/prometheus.yml",
 314         "--storage.tsdb.path=/prometheus",
 315         "--web.console.libraries=/usr/share/prometheus/console_libraries",
 316         "--web.console.templates=/usr/share/prometheus/consoles",
 317         "--web.route-prefix={}".format(config.get("web_subpath")),
 318         "--web.external-url=http://localhost:{}{}".format(
 319             port, config.get("web_subpath")
 320         ),
 321     ]
 322     if config.get("enable_web_admin_api"):
 323         command.append("--web.enable-admin-api")
 324     return command
 325
 326
 327 def make_pod_spec(
 328     image_info: Dict[str, str],
 329     config: Dict[str, Any],
 330     relation_state: Dict[str, Any],
 331     app_name: str = "prometheus",
 332     port: int = 9090,
 333 ) -> Dict[str, Any]:
 334     """Generate the pod spec information.
 335
 336     Args:
 337         image_info (Dict[str, str]): Object provided by
 338             OCIImageResource("image").fetch().
 339         config (Dict[str, Any]): Configuration information.
 340         relation_state (Dict[str, Any]): Relation state information.
 341         app_name (str, optional): Application name. Defaults to "ro".
 342         port (int, optional): Port for the container. Defaults to 9090.
 343
 344     Returns:
 345         Dict[str, Any]: Pod spec dictionary for the charm.
 346     """
 347     if not image_info:
 348         return None
 349
 350     _validate_data(config, relation_state)
 351
 352     ports = _make_pod_ports(port)
 353     env_config = _make_pod_envconfig(config, relation_state)
 354     files = _make_pod_files(config)
 355     readiness_probe = _make_readiness_probe(port)
 356     liveness_probe = _make_liveness_probe(port)
 357     ingress_resources = _make_pod_ingress_resources(config, app_name, port)
 358     command = _make_pod_command(config, port)
 359
 360     return {
 361         "version": 3,
 362         "containers": [
 363             {
 364                 "name": app_name,
 365                 "imageDetails": image_info,
 366                 "imagePullPolicy": "Always",
 367                 "ports": ports,
 368                 "envConfig": env_config,
 369                 "volumeConfig": files,
 370                 "command": command,
 371                 "kubernetes": {
 372                     "readinessProbe": readiness_probe,
 373                     "livenessProbe": liveness_probe,
 374                 },
 375             }
 376         ],
 377         "kubernetesResources": {
 378             "ingressResources": ingress_resources or [],
 379         },
 380     }