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Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Grafana Agent Cookbook Dynamic Configuration Objects
Open source

02 Datasources

Datasources can also access objects.

docker run -v ${PWD}/:/etc/grafana grafana/agentctl:latest template-parse file:///etc/grafana/03_config.yml

Config

The config.yml adds a new field sources. Sources can be any number of things defined in the gomplate datasources documentation. In this example using fruit.

yaml 
template_paths:
  - "file:///etc/grafana/03_assets"
datasources:
  - name: computers
    url: "file:///etc/grafana/03_assets/computers.json"

computers.json

json 
[
  {
    "name": "webhost1",
    "ip" : "192.168.1.1",
    "enabled": true
  },
  {
    "name": "webhost2",
    "ip" : "192.168.1.2",
    "enabled": false

  },
  {
    "name": "webhost3",
    "ip" : "192.168.1.3",
    "enabled": true
  }
]

Usage

agent-1.yml

yaml 
server:
  log_level: debug
metrics:
  wal_directory: /tmp/grafana-agent-normal
  global:
    scrape_interval: 60s
    remote_write:
      - url: https://prometheus-us-central1.grafana.net/api/prom/push
        basic_auth:
          username: xyz
          password: secretpassword
  configs:
    - name: default
      # Check for length so that if it is 0, we dont write any scrape configs
  {{ if $length := len (datasource "computers") }}
  {{ if gt $length 0 }}
  scrape_configs:
  {{ end }}
  {{ end }}
  {{ range (datasource "computers") }}
  # Only add if the computers are enabled
  # the . references our current object
  {{ if eq .enabled true }}
  - job_name: {{ .name }}
    static_configs:
      - targets:
          - {{ .ip }}
  {{ end }}
  {{ end }}

This is a much more complex example, in the above we are doing:

  • comparisons
  • creating and setting variables
  • looping over objects

The final output will only list webhost1 and webhost3 since webhost2 is not enabled.