Menu

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.

Documentationbreadcrumb arrow Grafana Agentbreadcrumb arrow Flow modebreadcrumb arrow Referencebreadcrumb arrow Componentsbreadcrumb arrow discovery.dns
Open source

discovery.dns

discovery.dns discovers scrape targets from DNS records.

Usage

river 
discovery.dns "LABEL" {
  names = ["lookup.example.com"]
}

Arguments

The following arguments are supported:

NameTypeDescriptionDefaultRequired
nameslist(string)DNS names to look up.yes
portnumberPort to use for collecting metrics. Not used for SRV records.0no
refresh_intervaldurationHow often to query DNS for updates."30s"no
typestringType of DNS record to query. Must be one of SRV, A, AAAA, or MX."SRV"no

Exported fields

The following field is exported and can be referenced by other components:

NameTypeDescription
targetslist(map(string))The set of targets discovered from the docker API.

Each target includes the following labels:

  • __meta_dns_name: Name of the record that produced the discovered target.
  • __meta_dns_srv_record_target: Target field of the SRV record.
  • __meta_dns_srv_record_port: Port field of the SRV record.
  • __meta_dns_mx_record_target: Target field of the MX record.

Component health

discovery.dns is only reported as unhealthy when given an invalid configuration. In those cases, exported fields retain their last healthy values.

Debug information

discovery.dns does not expose any component-specific debug information.

Debug metrics

discovery.dns does not expose any component-specific debug metrics.

Examples

This example discovers targets from an A record.

river 
discovery.dns "dns_lookup" {
  names = ["myservice.example.com", "myotherservice.example.com"]
  type = "A"
  port = 8080
}