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_whitelist_source_range: Optional[str]
  60     tls_secret_name: Optional[str]
  61     enable_web_admin_api: bool
  62
  63     @validator("web_subpath")
  64     def validate_web_subpath(cls, v):
  65         if len(v) < 1:
  66             raise ValueError("web-subpath must be a non-empty string")
  67         return v
  68
  69     @validator("max_file_size")
  70     def validate_max_file_size(cls, v):
  71         if v < 0:
  72             raise ValueError("value must be equal or greater than 0")
  73         return v
  74
  75     @validator("site_url")
  76     def validate_site_url(cls, v):
  77         if v:
  78             parsed = urlparse(v)
  79             if not parsed.scheme.startswith("http"):
  80                 raise ValueError("value must start with http")
  81         return v
  82
  83     @validator("ingress_whitelist_source_range")
  84     def validate_ingress_whitelist_source_range(cls, v):
  85         if v:
  86             ip_network(v)
  87         return v
  88
  89
  90 class PrometheusCharm(CharmedOsmBase):
  91
  92     """Prometheus Charm."""
  93
  94     def __init__(self, *args) -> NoReturn:
  95         """Prometheus Charm constructor."""
  96         super().__init__(*args, oci_image="image")
  97
  98         # Registering provided relation events
  99         self.prometheus = PrometheusServer(self, "prometheus")
 100         self.framework.observe(
 101             self.on.prometheus_relation_joined,  # pylint: disable=E1101
 102             self._publish_prometheus_info,
 103         )
 104
 105         # Registering actions
 106         self.framework.observe(
 107             self.on.backup_action,  # pylint: disable=E1101
 108             self._on_backup_action,
 109         )
 110
 111     def _publish_prometheus_info(self, event: EventBase) -> NoReturn:
 112         self.prometheus.publish_info(self.app.name, PORT)
 113
 114     def _on_backup_action(self, event: EventBase) -> NoReturn:
 115         url = f"http://{self.model.app.name}:{PORT}/api/v1/admin/tsdb/snapshot"
 116         result = requests.post(url)
 117
 118         if result.status_code == 200:
 119             event.set_results({"backup-name": result.json()["name"]})
 120         else:
 121             event.fail(f"status-code: {result.status_code}")
 122
 123     def _build_files(self, config: ConfigModel):
 124         files_builder = FilesV3Builder()
 125         files_builder.add_file(
 126             "prometheus.yml",
 127             (
 128                 "global:\n"
 129                 "  scrape_interval: 15s\n"
 130                 "  evaluation_interval: 15s\n"
 131                 "alerting:\n"
 132                 "  alertmanagers:\n"
 133                 "    - static_configs:\n"
 134                 "        - targets:\n"
 135                 "rule_files:\n"
 136                 "scrape_configs:\n"
 137                 "  - job_name: 'prometheus'\n"
 138                 "    static_configs:\n"
 139                 f"      - targets: [{config.default_target}]\n"
 140             ),
 141         )
 142         return files_builder.build()
 143
 144     def build_pod_spec(self, image_info):
 145         # Validate config
 146         config = ConfigModel(**dict(self.config))
 147         # Create Builder for the PodSpec
 148         pod_spec_builder = PodSpecV3Builder()
 149
 150         # Build Backup Container
 151         backup_image = OCIImageResource(self, "backup-image")
 152         backup_image_info = backup_image.fetch()
 153         backup_container_builder = ContainerV3Builder("prom-backup", backup_image_info)
 154         backup_container = backup_container_builder.build()
 155         # Add backup container to pod spec
 156         pod_spec_builder.add_container(backup_container)
 157
 158         # Build Container
 159         container_builder = ContainerV3Builder(self.app.name, image_info)
 160         container_builder.add_port(name=self.app.name, port=PORT)
 161         container_builder.add_http_readiness_probe(
 162             "/-/ready",
 163             PORT,
 164             initial_delay_seconds=10,
 165             timeout_seconds=30,
 166         )
 167         container_builder.add_http_liveness_probe(
 168             "/-/healthy",
 169             PORT,
 170             initial_delay_seconds=30,
 171             period_seconds=30,
 172         )
 173         command = [
 174             "/bin/prometheus",
 175             "--config.file=/etc/prometheus/prometheus.yml",
 176             "--storage.tsdb.path=/prometheus",
 177             "--web.console.libraries=/usr/share/prometheus/console_libraries",
 178             "--web.console.templates=/usr/share/prometheus/consoles",
 179             f"--web.route-prefix={config.web_subpath}",
 180             f"--web.external-url=http://localhost:{PORT}{config.web_subpath}",
 181         ]
 182         if config.enable_web_admin_api:
 183             command.append("--web.enable-admin-api")
 184         container_builder.add_command(command)
 185         container_builder.add_volume_config(
 186             "config", "/etc/prometheus", self._build_files(config)
 187         )
 188         container = container_builder.build()
 189         # Add container to pod spec
 190         pod_spec_builder.add_container(container)
 191         # Add ingress resources to pod spec if site url exists
 192         if config.site_url:
 193             parsed = urlparse(config.site_url)
 194             annotations = {
 195                 "nginx.ingress.kubernetes.io/proxy-body-size": "{}".format(
 196                     str(config.max_file_size) + "m"
 197                     if config.max_file_size > 0
 198                     else config.max_file_size
 199                 ),
 200                 "kubernetes.io/ingress.class": "public",
 201             }
 202             ingress_resource_builder = IngressResourceV3Builder(
 203                 f"{self.app.name}-ingress", annotations
 204             )
 205
 206             if config.ingress_whitelist_source_range:
 207                 annotations[
 208                     "nginx.ingress.kubernetes.io/whitelist-source-range"
 209                 ] = config.ingress_whitelist_source_range
 210
 211             if config.cluster_issuer:
 212                 annotations["cert-manager.io/cluster-issuer"] = config.cluster_issuer
 213
 214             if parsed.scheme == "https":
 215                 ingress_resource_builder.add_tls(
 216                     [parsed.hostname], config.tls_secret_name
 217                 )
 218             else:
 219                 annotations["nginx.ingress.kubernetes.io/ssl-redirect"] = "false"
 220
 221             ingress_resource_builder.add_rule(parsed.hostname, self.app.name, PORT)
 222             ingress_resource = ingress_resource_builder.build()
 223             pod_spec_builder.add_ingress_resource(ingress_resource)
 224         return pod_spec_builder.build()
 225
 226
 227 if __name__ == "__main__":
 228     main(PrometheusCharm)