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Caution

Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.

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.

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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.