Open source


discovery.hetzner allows retrieving scrape targets from Hetzner Cloud API and Robot API. This service discovery uses the public IPv4 address by default, but that can be changed with relabeling.


discovery.hetzner "LABEL" {


The following arguments are supported:

rolestringHetzner role of entities that should be discovered.yes
portintThe port to scrape metrics from.80no
refresh_intervaldurationThe time after which the servers are refreshed."60s"no
bearer_tokensecretBearer token to authenticate
bearer_token_filestringFile containing a bearer token to authenticate
proxy_urlstringHTTP proxy to proxy requests
follow_redirectsboolWhether redirects returned by the server should be followed.trueno
enable_http2boolWhether HTTP2 is supported for requests.trueno

role must be one of robot or hcloud.

You can provide one of the following arguments for authentication:


The following blocks are supported inside the definition of discovery.hetzner:

basic_authbasic_authConfigure basic_auth for authenticating to the
authorizationauthorizationConfigure generic authorization to the
oauth2oauth2Configure OAuth2 for authenticating to the
oauth2 > tls_configtls_configConfigure TLS settings for connecting to the

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

usernamestringBasic auth
passwordsecretBasic auth
password_filestringFile containing the basic auth

password and password_file are mutually exclusive and only one can be provided inside of a basic_auth block.

authorization block

typestringAuthorization type, for example, “Bearer”.no
credentials_filestringFile containing the secret

credential and credentials_file are mutually exclusive and only one can be provided inside of an authorization block.

oauth2 block

client_idstringOAuth2 client
client_secretsecretOAuth2 client
client_secret_filestringFile containing the OAuth2 client
scopeslist(string)List of scopes to authenticate
token_urlstringURL to fetch the token
endpoint_paramsmap(string)Optional parameters to append to the token
proxy_urlstringOptional proxy URL for OAuth2

client_secret and client_secret_file are mutually exclusive and only one can be provided inside of an oauth2 block.

The oauth2 block may also contain its own separate tls_config sub-block.

tls_config block

ca_pemstringCA PEM-encoded text to validate the server
ca_filestringCA certificate to validate the server
cert_pemstringCertificate PEM-encoded text for client
cert_filestringCertificate file for client
key_pemsecretKey PEM-encoded text for client
key_filestringKey file for client
server_namestringServerName extension to indicate the name of the
insecure_skip_verifyboolDisables validation of the server
min_versionstringMinimum acceptable TLS

The following pairs of arguments are mutually exclusive and cannot both be set simultaneously:

  • ca_pem and ca_file
  • cert_pem and cert_file
  • key_pem and key_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:

targetslist(map(string))The set of targets discovered from the Hetzner catalog API.

Each target includes the following labels:

  • __meta_hetzner_server_id: the ID of the server
  • __meta_hetzner_server_name: the name of the server
  • __meta_hetzner_server_status: the status of the server
  • __meta_hetzner_public_ipv4: the public ipv4 address of the server
  • __meta_hetzner_public_ipv6_network: the public ipv6 network (/64) of the server
  • __meta_hetzner_datacenter: the datacenter of the server


The labels below are only available for targets with role set to hcloud:

  • __meta_hetzner_hcloud_image_name: the image name of the server
  • __meta_hetzner_hcloud_image_description: the description of the server image
  • __meta_hetzner_hcloud_image_os_flavor: the OS flavor of the server image
  • __meta_hetzner_hcloud_image_os_version: the OS version of the server image
  • __meta_hetzner_hcloud_datacenter_location: the location of the server
  • __meta_hetzner_hcloud_datacenter_location_network_zone: the network zone of the server
  • __meta_hetzner_hcloud_server_type: the type of the server
  • __meta_hetzner_hcloud_cpu_cores: the CPU cores count of the server
  • __meta_hetzner_hcloud_cpu_type: the CPU type of the server (shared or dedicated)
  • __meta_hetzner_hcloud_memory_size_gb: the amount of memory of the server (in GB)
  • __meta_hetzner_hcloud_disk_size_gb: the disk size of the server (in GB)
  • __meta_hetzner_hcloud_private_ipv4_<networkname>: the private ipv4 address of the server within a given network
  • __meta_hetzner_hcloud_label_<labelname>: each label of the server
  • __meta_hetzner_hcloud_labelpresent_<labelname>: true for each label of the server


The labels below are only available for targets with role set to robot:

  • __meta_hetzner_robot_product: the product of the server
  • __meta_hetzner_robot_cancelled: the server cancellation status

Component health

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

Debug information

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

Debug metrics

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


This example discovers targets from Hetzner:

discovery.hetzner "example" {

prometheus.scrape "demo" {
  targets    = discovery.hetzner.example.targets
  forward_to = [prometheus.remote_write.demo.receiver]

prometheus.remote_write "demo" {
  endpoint {

    basic_auth {
      username = USERNAME
      password = PASSWORD

Replace the following:

  • HETZNER_ROLE: The role of the entities that should be discovered.
  • 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.