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     ingress_whitelist_source_range: Optional[str]
  59     tls_secret_name: Optional[str]
  60     enable_web_admin_api: bool
  61
  62     @validator("web_subpath")
  63     def validate_web_subpath(cls, v):
  64         if len(v) < 1:
  65             raise ValueError("web-subpath must be a non-empty string")
  66         return v
  67
  68     @validator("max_file_size")
  69     def validate_max_file_size(cls, v):
  70         if v < 0:
  71             raise ValueError("value must be equal or greater than 0")
  72         return v
  73
  74     @validator("site_url")
  75     def validate_site_url(cls, v):
  76         if v:
  77             parsed = urlparse(v)
  78             if not parsed.scheme.startswith("http"):
  79                 raise ValueError("value must start with http")
  80         return v
  81
  82     @validator("ingress_whitelist_source_range")
  83     def validate_ingress_whitelist_source_range(cls, v):
  84         if v:
  85             ip_network(v)
  86         return v
  87
  88
  89 class PrometheusCharm(CharmedOsmBase):
  90
  91     """Prometheus Charm."""
  92
  93     def __init__(self, *args) -> NoReturn:
  94         """Prometheus Charm constructor."""
  95         super().__init__(*args, oci_image="image")
  96
  97         # Registering provided relation events
  98         self.prometheus = PrometheusServer(self, "prometheus")
  99         self.framework.observe(
 100             self.on.prometheus_relation_joined,  # pylint: disable=E1101
 101             self._publish_prometheus_info,
 102         )
 103
 104         # Registering actions
 105         self.framework.observe(
 106             self.on.backup_action,  # pylint: disable=E1101
 107             self._on_backup_action,
 108         )
 109
 110     def _publish_prometheus_info(self, event: EventBase) -> NoReturn:
 111         self.prometheus.publish_info(self.app.name, PORT)
 112
 113     def _on_backup_action(self, event: EventBase) -> NoReturn:
 114         url = f"http://{self.model.app.name}:{PORT}/api/v2/admin/tsdb/snapshot"
 115         result = requests.post(url)
 116
 117         if result.status_code == 200:
 118             event.set_results({"backup-name": result.json()["name"]})
 119         else:
 120             event.fail(f"status-code: {result.status_code}, result: {result.json()}")
 121
 122     def _build_files(self, config: ConfigModel):
 123         files_builder = FilesV3Builder()
 124         files_builder.add_file(
 125             "prometheus.yml",
 126             (
 127                 "global:\n"
 128                 "  scrape_interval: 15s\n"
 129                 "  evaluation_interval: 15s\n"
 130                 "alerting:\n"
 131                 "  alertmanagers:\n"
 132                 "    - static_configs:\n"
 133                 "        - targets:\n"
 134                 "rule_files:\n"
 135                 "scrape_configs:\n"
 136                 "  - job_name: 'prometheus'\n"
 137                 "    static_configs:\n"
 138                 f"      - targets: [{config.default_target}]\n"
 139             ),
 140         )
 141         return files_builder.build()
 142
 143     def build_pod_spec(self, image_info):
 144         # Validate config
 145         config = ConfigModel(**dict(self.config))
 146         # Create Builder for the PodSpec
 147         pod_spec_builder = PodSpecV3Builder()
 148
 149         # Build Backup Container
 150         backup_image = OCIImageResource(self, "backup-image")
 151         backup_image_info = backup_image.fetch()
 152         backup_container_builder = ContainerV3Builder("prom-backup", backup_image_info)
 153         backup_container = backup_container_builder.build()
 154         # Add backup container to pod spec
 155         pod_spec_builder.add_container(backup_container)
 156
 157         # Build Container
 158         container_builder = ContainerV3Builder(self.app.name, image_info)
 159         container_builder.add_port(name=self.app.name, port=PORT)
 160         container_builder.add_http_readiness_probe(
 161             "/-/ready",
 162             PORT,
 163             initial_delay_seconds=10,
 164             timeout_seconds=30,
 165         )
 166         container_builder.add_http_liveness_probe(
 167             "/-/healthy",
 168             PORT,
 169             initial_delay_seconds=30,
 170             period_seconds=30,
 171         )
 172         command = [
 173             "/bin/prometheus",
 174             "--config.file=/etc/prometheus/prometheus.yml",
 175             "--storage.tsdb.path=/prometheus",
 176             "--web.console.libraries=/usr/share/prometheus/console_libraries",
 177             "--web.console.templates=/usr/share/prometheus/consoles",
 178             f"--web.route-prefix={config.web_subpath}",
 179             f"--web.external-url=http://localhost:{PORT}{config.web_subpath}",
 180         ]
 181         if config.enable_web_admin_api:
 182             command.append("--web.enable-admin-api")
 183         container_builder.add_command(command)
 184         container_builder.add_volume_config(
 185             "config", "/etc/prometheus", self._build_files(config)
 186         )
 187         container = container_builder.build()
 188         # Add container to pod spec
 189         pod_spec_builder.add_container(container)
 190         # Add ingress resources to pod spec if site url exists
 191         if config.site_url:
 192             parsed = urlparse(config.site_url)
 193             annotations = {
 194                 "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
 195                     str(config.max_file_size) + "m"
 196                     if config.max_file_size > 0
 197                     else config.max_file_size
 198                 ),
 199             }
 200             ingress_resource_builder = IngressResourceV3Builder(
 201                 f"{self.app.name}-ingress", annotations
 202             )
 203
 204             if config.ingress_whitelist_source_range:
 205                 annotations[
 206                     "nginx.ingress.kubernetes.io/whitelist-source-range"
 207                 ] = config.ingress_whitelist_source_range
 208
 209             if parsed.scheme == "https":
 210                 ingress_resource_builder.add_tls(
 211                     [parsed.hostname], config.tls_secret_name
 212                 )
 213             else:
 214                 annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 215
 216             ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
 217             ingress_resource = ingress_resource_builder.build()
 218             pod_spec_builder.add_ingress_resource(ingress_resource)
 219         return pod_spec_builder.build()
 220
 221
 222 if __name__ == "__main__":
 223     main(PrometheusCharm)