This is documentation for the next version of Alloy. For the latest stable release, go to the latest 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, MX, or NS. | "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.__meta_dns_ns_record_target
: Target field of the NS 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.
Compatible components
discovery.dns
has exports that can be consumed by the following components:
- Components that consume Targets
Note
Connecting some components may not be sensible or components may require further configuration to make the connection work correctly. Refer to the linked documentation for more details.