cos_agent/v0

Usage

The cos_agent interface is meant to exchange information on several observability-related data streams at once. This is a SUBORDINATE, ergo MACHINE-charm-specific relation interface.

Direction

        flowchart TD
    Provider["Provider (e.g. kafka)"] -- "relation_name
    metrics_endpoints
    metrics_rules_dir
    logs_rules_dir
    recursive_rules_dir
    log_slots
    dashboard_dirs
    refresh_events" --> Requirer
    Requirer["Requirer (e.g. grafana-agent)"] -- refresh_events --> Provider
    

As all Juju relations, the cos_agent interface consists of a provider and a requirer. In this case the Provider side of the relationship may provide telemetry settings, if not, the required side will use default values.

Behavior

Provider

• Is expected to be able to provide metrics endpoints to be scraped.

• Is expected to be able to provide a directory containing Prometheus style metrics rules files.

• Is expected to be able to provide a directory containing Loki style rules files.

• Is expected to be able to inform if metrics and logs rules directories should be scanned recursively.

• Is expected to be able to provide snap slots to connect to for scraping logs.

• Is expected to be able to provide a list of directories containing Grafana dashboard files.

• Is expected to be able to provide a list of events on which to refresh relation data.

Relation Data

Provider

[[JSON Schema]]

Unit data

• Exposes mtrics_alert_rules, log_alert_rules, and log_slots

Example

{
  "config": {
    "metrics_alert_rules": {
      "groups": [
        {
          "name": "test_58b48ff0_zookeeper_cos_23790144_zinc",
          "rules": [
            {
              "alert": "ZincTargetMissing",
              "annotations": {
                "description": "A Prometheus target has disappeared. An exporter might be crashed.\n  VALUE = {{ $value }}\n  LABELS = {{ $labels }}",
                "summary": "Prometheus target missing (instance {{ $labels.instance}})"
              },
              "expr": "up{juju_application=\"zinc2\"} == 0",
              "for": "0m",
              "labels": {
                "app_group": "cloud",
                "juju_application": "zookeeper",
                "juju_charm": "zookeeper",
                "juju_model": "test",
                "juju_model_uuid": "58b48ff0-608b-435f-83b9-ea643e0b98db",
                "severity": "critical"
              }
            }
          ]
        }
      ]
    },
    "log_alert_rules": {},
    /* Dashboards list with base64 encoded, lzma-compressed, json-dumped dashboard data */
    "dashboards": [
      "/Td6WFoAAATm1rRGAgAhARYAAAB0L+Wj6hvVPXVdA…",
      "/Td6WFoAAATm1rRGAgAhARYAAAB0L+Wj6hvVPXVdB…"
    ],
    "log_slots": [
      "charmed-zookeeper:logs"
    ],
    "metrics_scrape_jobs": [{"job_name": "kafka_0", "path": "/metrics", "port": 9101}],
  }
}