installers/charm/prometheus/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 typing import NoReturn, Optional
  28 from urllib.parse import urlparse
  29
  30 from oci_image import OCIImageResource
  31 from ops.framework import EventBase
  32 from ops.main import main
  33 from opslib.osm.charm import CharmedOsmBase
  34 from opslib.osm.interfaces.prometheus import PrometheusServer
  35 from opslib.osm.pod import (
  36     ContainerV3Builder,
  37     FilesV3Builder,
  38     IngressResourceV3Builder,
  39     PodSpecV3Builder,
  40 )
  41 from opslib.osm.validator import (
  42     ModelValidator,
  43     validator,
  44 )
  45 import requests
  46
  47
  48 logger = logging.getLogger(__name__)
  49
  50 PORT = 9090
  51
  52
  53 class ConfigModel(ModelValidator):
  54     web_subpath: str
  55     default_target: str
  56     max_file_size: int
  57     site_url: Optional[str]
  58     cluster_issuer: Optional[str]
  59     ingress_class: Optional[str]
  60     ingress_whitelist_source_range: Optional[str]
  61     tls_secret_name: Optional[str]
  62     enable_web_admin_api: bool
  63     image_pull_policy: str
  64
  65     @validator("web_subpath")
  66     def validate_web_subpath(cls, v):
  67         if len(v) < 1:
  68             raise ValueError("web-subpath must be a non-empty string")
  69         return v
  70
  71     @validator("max_file_size")
  72     def validate_max_file_size(cls, v):
  73         if v < 0:
  74             raise ValueError("value must be equal or greater than 0")
  75         return v
  76
  77     @validator("site_url")
  78     def validate_site_url(cls, v):
  79         if v:
  80             parsed = urlparse(v)
  81             if not parsed.scheme.startswith("http"):
  82                 raise ValueError("value must start with http")
  83         return v
  84
  85     @validator("ingress_whitelist_source_range")
  86     def validate_ingress_whitelist_source_range(cls, v):
  87         if v:
  88             ip_network(v)
  89         return v
  90
  91     @validator("image_pull_policy")
  92     def validate_image_pull_policy(cls, v):
  93         values = {
  94             "always": "Always",
  95             "ifnotpresent": "IfNotPresent",
  96             "never": "Never",
  97         }
  98         v = v.lower()
  99         if v not in values.keys():
 100             raise ValueError("value must be always, ifnotpresent or never")
 101         return values[v]
 102
 103
 104 class PrometheusCharm(CharmedOsmBase):
 105
 106     """Prometheus Charm."""
 107
 108     def __init__(self, *args) -> NoReturn:
 109         """Prometheus Charm constructor."""
 110         super().__init__(*args, oci_image="image")
 111
 112         # Registering provided relation events
 113         self.prometheus = PrometheusServer(self, "prometheus")
 114         self.framework.observe(
 115             self.on.prometheus_relation_joined,  # pylint: disable=E1101
 116             self._publish_prometheus_info,
 117         )
 118
 119         # Registering actions
 120         self.framework.observe(
 121             self.on.backup_action,  # pylint: disable=E1101
 122             self._on_backup_action,
 123         )
 124
 125     def _publish_prometheus_info(self, event: EventBase) -> NoReturn:
 126         self.prometheus.publish_info(self.app.name, PORT)
 127
 128     def _on_backup_action(self, event: EventBase) -> NoReturn:
 129         url = f"http://{self.model.app.name}:{PORT}/api/v1/admin/tsdb/snapshot"
 130         result = requests.post(url)
 131
 132         if result.status_code == 200:
 133             event.set_results({"backup-name": result.json()["name"]})
 134         else:
 135             event.fail(f"status-code: {result.status_code}")
 136
 137     def _build_files(self, config: ConfigModel):
 138         files_builder = FilesV3Builder()
 139         files_builder.add_file(
 140             "prometheus.yml",
 141             (
 142                 "global:\n"
 143                 "  scrape_interval: 15s\n"
 144                 "  evaluation_interval: 15s\n"
 145                 "alerting:\n"
 146                 "  alertmanagers:\n"
 147                 "    - static_configs:\n"
 148                 "        - targets:\n"
 149                 "rule_files:\n"
 150                 "scrape_configs:\n"
 151                 "  - job_name: 'prometheus'\n"
 152                 "    static_configs:\n"
 153                 f"      - targets: [{config.default_target}]\n"
 154             ),
 155         )
 156         return files_builder.build()
 157
 158     def build_pod_spec(self, image_info):
 159         # Validate config
 160         config = ConfigModel(**dict(self.config))
 161         # Create Builder for the PodSpec
 162         pod_spec_builder = PodSpecV3Builder()
 163
 164         # Build Backup Container
 165         backup_image = OCIImageResource(self, "backup-image")
 166         backup_image_info = backup_image.fetch()
 167         backup_container_builder = ContainerV3Builder("prom-backup", backup_image_info)
 168         backup_container = backup_container_builder.build()
 169         # Add backup container to pod spec
 170         pod_spec_builder.add_container(backup_container)
 171
 172         # Build Container
 173         container_builder = ContainerV3Builder(
 174             self.app.name, image_info, config.image_pull_policy
 175         )
 176         container_builder.add_port(name=self.app.name, port=PORT)
 177         container_builder.add_http_readiness_probe(
 178             "/-/ready",
 179             PORT,
 180             initial_delay_seconds=10,
 181             timeout_seconds=30,
 182         )
 183         container_builder.add_http_liveness_probe(
 184             "/-/healthy",
 185             PORT,
 186             initial_delay_seconds=30,
 187             period_seconds=30,
 188         )
 189         command = [
 190             "/bin/prometheus",
 191             "--config.file=/etc/prometheus/prometheus.yml",
 192             "--storage.tsdb.path=/prometheus",
 193             "--web.console.libraries=/usr/share/prometheus/console_libraries",
 194             "--web.console.templates=/usr/share/prometheus/consoles",
 195             f"--web.route-prefix={config.web_subpath}",
 196             f"--web.external-url=http://localhost:{PORT}{config.web_subpath}",
 197         ]
 198         if config.enable_web_admin_api:
 199             command.append("--web.enable-admin-api")
 200         container_builder.add_command(command)
 201         container_builder.add_volume_config(
 202             "config", "/etc/prometheus", self._build_files(config)
 203         )
 204         container = container_builder.build()
 205         # Add container to pod spec
 206         pod_spec_builder.add_container(container)
 207         # Add ingress resources to pod spec if site url exists
 208         if config.site_url:
 209             parsed = urlparse(config.site_url)
 210             annotations = {
 211                 "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
 212                     str(config.max_file_size) + "m"
 213                     if config.max_file_size > 0
 214                     else config.max_file_size
 215                 )
 216             }
 217             if config.ingress_class:
 218                 annotations["kubernetes.io/ingress.class"] = config.ingress_class
 219             ingress_resource_builder = IngressResourceV3Builder(
 220                 f"{self.app.name}-ingress", annotations
 221             )
 222
 223             if config.ingress_whitelist_source_range:
 224                 annotations[
 225                     "nginx.ingress.kubernetes.io/whitelist-source-range"
 226                 ] = config.ingress_whitelist_source_range
 227
 228             if config.cluster_issuer:
 229                 annotations["cert-manager.io/cluster-issuer"] = config.cluster_issuer
 230
 231             if parsed.scheme == "https":
 232                 ingress_resource_builder.add_tls(
 233                     [parsed.hostname], config.tls_secret_name
 234                 )
 235             else:
 236                 annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 237
 238             ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
 239             ingress_resource = ingress_resource_builder.build()
 240             pod_spec_builder.add_ingress_resource(ingress_resource)
 241         return pod_spec_builder.build()
 242
 243
 244 if __name__ == "__main__":
 245     main(PrometheusCharm)