installers/charm/mongodb-exporter/src/charm.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 # pylint: disable=E0213
  24
  25 from ipaddress import ip_network
  26 import logging
  27 from pathlib import Path
  28 from typing import NoReturn, Optional
  29 from urllib.parse import urlparse
  30
  31 from ops.main import main
  32 from opslib.osm.charm import CharmedOsmBase, RelationsMissing
  33 from opslib.osm.interfaces.grafana import GrafanaDashboardTarget
  34 from opslib.osm.interfaces.mongo import MongoClient
  35 from opslib.osm.interfaces.prometheus import PrometheusScrapeTarget
  36 from opslib.osm.pod import (
  37     ContainerV3Builder,
  38     IngressResourceV3Builder,
  39     PodRestartPolicy,
  40     PodSpecV3Builder,
  41 )
  42 from opslib.osm.validator import ModelValidator, validator
  43
  44
  45 logger = logging.getLogger(__name__)
  46
  47 PORT = 9216
  48
  49
  50 class ConfigModel(ModelValidator):
  51     site_url: Optional[str]
  52     cluster_issuer: Optional[str]
  53     ingress_class: Optional[str]
  54     ingress_whitelist_source_range: Optional[str]
  55     tls_secret_name: Optional[str]
  56     mongodb_uri: Optional[str]
  57     image_pull_policy: str
  58     security_context: bool
  59
  60     @validator("site_url")
  61     def validate_site_url(cls, v):
  62         if v:
  63             parsed = urlparse(v)
  64             if not parsed.scheme.startswith("http"):
  65                 raise ValueError("value must start with http")
  66         return v
  67
  68     @validator("ingress_whitelist_source_range")
  69     def validate_ingress_whitelist_source_range(cls, v):
  70         if v:
  71             ip_network(v)
  72         return v
  73
  74     @validator("mongodb_uri")
  75     def validate_mongodb_uri(cls, v):
  76         if v and not v.startswith("mongodb://"):
  77             raise ValueError("mongodb_uri is not properly formed")
  78         return v
  79
  80     @validator("image_pull_policy")
  81     def validate_image_pull_policy(cls, v):
  82         values = {
  83             "always": "Always",
  84             "ifnotpresent": "IfNotPresent",
  85             "never": "Never",
  86         }
  87         v = v.lower()
  88         if v not in values.keys():
  89             raise ValueError("value must be always, ifnotpresent or never")
  90         return values[v]
  91
  92
  93 class MongodbExporterCharm(CharmedOsmBase):
  94     def __init__(self, *args) -> NoReturn:
  95         super().__init__(*args, oci_image="image")
  96
  97         # Provision Kafka relation to exchange information
  98         self.mongodb_client = MongoClient(self, "mongodb")
  99         self.framework.observe(self.on["mongodb"].relation_changed, self.configure_pod)
 100         self.framework.observe(self.on["mongodb"].relation_broken, self.configure_pod)
 101
 102         # Register relation to provide a Scraping Target
 103         self.scrape_target = PrometheusScrapeTarget(self, "prometheus-scrape")
 104         self.framework.observe(
 105             self.on["prometheus-scrape"].relation_joined, self._publish_scrape_info
 106         )
 107
 108         # Register relation to provide a Dasboard Target
 109         self.dashboard_target = GrafanaDashboardTarget(self, "grafana-dashboard")
 110         self.framework.observe(
 111             self.on["grafana-dashboard"].relation_joined, self._publish_dashboard_info
 112         )
 113
 114     def _publish_scrape_info(self, event) -> NoReturn:
 115         """Publishes scraping information for Prometheus.
 116
 117         Args:
 118             event (EventBase): Prometheus relation event.
 119         """
 120         if self.unit.is_leader():
 121             hostname = (
 122                 urlparse(self.model.config["site_url"]).hostname
 123                 if self.model.config["site_url"]
 124                 else self.model.app.name
 125             )
 126             port = str(PORT)
 127             if self.model.config.get("site_url", "").startswith("https://"):
 128                 port = "443"
 129             elif self.model.config.get("site_url", "").startswith("http://"):
 130                 port = "80"
 131
 132             self.scrape_target.publish_info(
 133                 hostname=hostname,
 134                 port=port,
 135                 metrics_path="/metrics",
 136                 scrape_interval="30s",
 137                 scrape_timeout="15s",
 138             )
 139
 140     def _publish_dashboard_info(self, event) -> NoReturn:
 141         """Publish dashboards for Grafana.
 142
 143         Args:
 144             event (EventBase): Grafana relation event.
 145         """
 146         if self.unit.is_leader():
 147             self.dashboard_target.publish_info(
 148                 name="osm-mongodb",
 149                 dashboard=Path("templates/mongodb_exporter_dashboard.json").read_text(),
 150             )
 151
 152     def _check_missing_dependencies(self, config: ConfigModel):
 153         """Check if there is any relation missing.
 154
 155         Args:
 156             config (ConfigModel): object with configuration information.
 157
 158         Raises:
 159             RelationsMissing: if kafka is missing.
 160         """
 161         missing_relations = []
 162
 163         if not config.mongodb_uri and self.mongodb_client.is_missing_data_in_unit():
 164             missing_relations.append("mongodb")
 165
 166         if missing_relations:
 167             raise RelationsMissing(missing_relations)
 168
 169     def build_pod_spec(self, image_info):
 170         """Build the PodSpec to be used.
 171
 172         Args:
 173             image_info (str): container image information.
 174
 175         Returns:
 176             Dict: PodSpec information.
 177         """
 178         # Validate config
 179         config = ConfigModel(**dict(self.config))
 180
 181         if config.mongodb_uri and not self.mongodb_client.is_missing_data_in_unit():
 182             raise Exception("Mongodb data cannot be provided via config and relation")
 183
 184         # Check relations
 185         self._check_missing_dependencies(config)
 186
 187         unparsed = (
 188             config.mongodb_uri
 189             if config.mongodb_uri
 190             else self.mongodb_client.connection_string
 191         )
 192         parsed = urlparse(unparsed)
 193         mongodb_uri = f"mongodb://{parsed.netloc.split(',')[0]}{parsed.path}"
 194         if parsed.query:
 195             mongodb_uri += f"?{parsed.query}"
 196
 197         # Create Builder for the PodSpec
 198         pod_spec_builder = PodSpecV3Builder(
 199             enable_security_context=config.security_context
 200         )
 201
 202         # Add secrets to the pod
 203         mongodb_secret_name = f"{self.app.name}-mongodb-secret"
 204         pod_spec_builder.add_secret(mongodb_secret_name, {"uri": mongodb_uri})
 205
 206         # Build container
 207         container_builder = ContainerV3Builder(
 208             self.app.name,
 209             image_info,
 210             config.image_pull_policy,
 211             run_as_non_root=config.security_context,
 212         )
 213         container_builder.add_port(name=self.app.name, port=PORT)
 214         container_builder.add_http_readiness_probe(
 215             path="/api/health",
 216             port=PORT,
 217             initial_delay_seconds=10,
 218             period_seconds=10,
 219             timeout_seconds=5,
 220             success_threshold=1,
 221             failure_threshold=3,
 222         )
 223         container_builder.add_http_liveness_probe(
 224             path="/api/health",
 225             port=PORT,
 226             initial_delay_seconds=60,
 227             timeout_seconds=30,
 228             failure_threshold=10,
 229         )
 230
 231         container_builder.add_secret_envs(mongodb_secret_name, {"MONGODB_URI": "uri"})
 232         container = container_builder.build()
 233
 234         # Add container to PodSpec
 235         pod_spec_builder.add_container(container)
 236
 237         # Add Pod restart policy
 238         restart_policy = PodRestartPolicy()
 239         restart_policy.add_secrets(secret_names=(mongodb_secret_name,))
 240         pod_spec_builder.set_restart_policy(restart_policy)
 241
 242         # Add ingress resources to PodSpec if site url exists
 243         if config.site_url:
 244             parsed = urlparse(config.site_url)
 245             annotations = {}
 246             if config.ingress_class:
 247                 annotations["kubernetes.io/ingress.class"] = config.ingress_class
 248             ingress_resource_builder = IngressResourceV3Builder(
 249                 f"{self.app.name}-ingress", annotations
 250             )
 251
 252             if config.ingress_whitelist_source_range:
 253                 annotations[
 254                     "nginx.ingress.kubernetes.io/whitelist-source-range"
 255                 ] = config.ingress_whitelist_source_range
 256
 257             if config.cluster_issuer:
 258                 annotations["cert-manager.io/cluster-issuer"] = config.cluster_issuer
 259
 260             if parsed.scheme == "https":
 261                 ingress_resource_builder.add_tls(
 262                     [parsed.hostname], config.tls_secret_name
 263                 )
 264             else:
 265                 annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 266
 267             ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
 268             ingress_resource = ingress_resource_builder.build()
 269             pod_spec_builder.add_ingress_resource(ingress_resource)
 270
 271         return pod_spec_builder.build()
 272
 273
 274 if __name__ == "__main__":
 275     main(MongodbExporterCharm)