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.
discovery.dns
discovery.dns
discovers scrape targets from DNS records.
Usage
discovery.dns "LABEL" {
names = [NAME_1, NAME_2, ...]
}
Arguments
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
names | list(string) | DNS names to look up. | yes | |
port | number | Port to use for collecting metrics. Not used for SRV records. | 0 | no |
refresh_interval | duration | How often to query DNS for updates. | "30s" | no |
type | string | Type 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:
Name | Type | Description |
---|---|---|
targets | list(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.
Example
This example discovers targets from an A record.
discovery.dns "dns_lookup" {
names = ["myservice.example.com", "myotherservice.example.com"]
type = "A"
port = 8080
}
prometheus.scrape "demo" {
targets = discovery.dns.dns_lookup.targets
forward_to = [prometheus.remote_write.demo.receiver]
}
prometheus.remote_write "demo" {
endpoint {
url = PROMETHEUS_REMOTE_WRITE_URL
basic_auth {
username = USERNAME
password = PASSWORD
}
}
}
Replace the following:
PROMETHEUS_REMOTE_WRITE_URL
: The URL of the Prometheus remote_write-compatible server to send metrics to.USERNAME
: The username to use for authentication to the remote_write API.PASSWORD
: The password to use for authentication to the remote_write API.