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.nomad
discovery.nomad
allows you to retrieve scrape targets from Nomad’s Service API.
Usage
discovery.nomad "LABEL" {
server = NOMAD_SERVER
}
Arguments
The following arguments are supported:
Name | Type | Description | Default | Required |
---|---|---|---|---|
server | string | Address of nomad server. | http://localhost:4646 | no |
namespace | string | Nomad namespace to use. | default | no |
region | string | Nomad region to use. | global | no |
allow_stale | bool | Allow reading from non-leader nomad instances. | true | no |
tag_separator | string | Seperator to join nomad tags into Prometheus labels. | , | no |
refresh_interval | duration | Frequency to refresh list of containers. | "30s" | no |
bearer_token | secret | Bearer token to authenticate with. | no | |
bearer_token_file | string | File containing a bearer token to authenticate with. | no | |
proxy_url | string | HTTP proxy to proxy requests through. | no | |
follow_redirects | bool | Whether redirects returned by the server should be followed. | true | no |
enable_http2 | bool | Whether HTTP2 is supported for requests. | true | no |
You can provide one of the following arguments for authentication:
Blocks
The following blocks are supported inside the definition of
discovery.nomad
:
Hierarchy | Block | Description | Required |
---|---|---|---|
basic_auth | basic_auth | Configure basic_auth for authenticating to the endpoint. | no |
authorization | authorization | Configure generic authorization to the endpoint. | no |
oauth2 | oauth2 | Configure OAuth2 for authenticating to the endpoint. | no |
oauth2 > tls_config | tls_config | Configure TLS settings for connecting to the endpoint. | no |
The >
symbol indicates deeper levels of nesting. For example,
oauth2 > tls_config
refers to a tls_config
block defined inside
an oauth2
block.
basic_auth block
Name | Type | Description | Default | Required |
---|---|---|---|---|
password_file | string | File containing the basic auth password. | no | |
password | secret | Basic auth password. | no | |
username | string | Basic auth username. | no |
password
and password_file
are mutually exclusive, and only one can be provided inside a basic_auth
block.
authorization block
Name | Type | Description | Default | Required |
---|---|---|---|---|
credentials_file | string | File containing the secret value. | no | |
credentials | secret | Secret value. | no | |
type | string | Authorization type, for example, “Bearer”. | no |
credential
and credentials_file
are mutually exclusive, and only one can be provided inside an authorization
block.
oauth2 block
Name | Type | Description | Default | Required |
---|---|---|---|---|
client_id | string | OAuth2 client ID. | no | |
client_secret_file | string | File containing the OAuth2 client secret. | no | |
client_secret | secret | OAuth2 client secret. | no | |
endpoint_params | map(string) | Optional parameters to append to the token URL. | no | |
proxy_url | string | Optional proxy URL for OAuth2 requests. | no | |
scopes | list(string) | List of scopes to authenticate with. | no | |
token_url | string | URL to fetch the token from. | no |
client_secret
and client_secret_file
are mutually exclusive, and only one can be provided inside an oauth2
block.
The oauth2
block may also contain a separate tls_config
sub-block.
tls_config block
Name | Type | Description | Default | Required |
---|---|---|---|---|
ca_pem | string | CA PEM-encoded text to validate the server with. | no | |
ca_file | string | CA certificate to validate the server with. | no | |
cert_pem | string | Certificate PEM-encoded text for client authentication. | no | |
cert_file | string | Certificate file for client authentication. | no | |
insecure_skip_verify | bool | Disables validation of the server certificate. | no | |
key_file | string | Key file for client authentication. | no | |
key_pem | secret | Key PEM-encoded text for client authentication. | no | |
min_version | string | Minimum acceptable TLS version. | no | |
server_name | string | ServerName extension to indicate the name of the server. | no |
The following pairs of arguments are mutually exclusive and can’t both be set simultaneously:
ca_pem
andca_file
cert_pem
andcert_file
key_pem
andkey_file
When configuring client authentication, both the client certificate (using
cert_pem
or cert_file
) and the client key (using key_pem
or key_file
)
must be provided.
When min_version
is not provided, the minimum acceptable TLS version is
inherited from Go’s default minimum version, TLS 1.2. If min_version
is
provided, it must be set to one of the following strings:
"TLS10"
(TLS 1.0)"TLS11"
(TLS 1.1)"TLS12"
(TLS 1.2)"TLS13"
(TLS 1.3)
Exported fields
The following fields are exported and can be referenced by other components:
Name | Type | Description |
---|---|---|
targets | list(map(string)) | The set of targets discovered from the nomad server. |
Each target includes the following labels:
__meta_nomad_address
: the service address of the target.__meta_nomad_dc
: the datacenter name for the target.__meta_nomad_namespace
: the namespace of the target.__meta_nomad_node_id
: the node name defined for the target.__meta_nomad_service
: the name of the service the target belongs to.__meta_nomad_service_address
: the service address of the target.__meta_nomad_service_id
: the service ID of the target.__meta_nomad_service_port
: the service port of the target.__meta_nomad_tags
: the list of tags of the target joined by the tag separator.
Component health
discovery.nomad
is only reported as unhealthy when given an invalid
configuration. In those cases, exported fields retain their last healthy
values.
Debug information
discovery.nomad
does not expose any component-specific debug information.
Debug metrics
discovery.nomad
does not expose any component-specific debug metrics.
Example
This example discovers targets from a Nomad server:
discovery.nomad "example" {
server = "localhost:8500"
}
prometheus.scrape "demo" {
targets = discovery.nomad.example.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.