Open source


discovery.http provides a flexible way to define targets by querying an external http endpoint.

It fetches targets from an HTTP endpoint containing a list of zero or more target definitions. The target must reply with an HTTP 200 response. The HTTP header Content-Type must be application/json, and the body must be valid JSON.

Example response body:

    "targets": [ "<host>", ... ],
    "labels": {
      "<labelname>": "<labelvalue>", ...


discovery.http "LABEL" {
  url = URL


The following arguments are supported:

urlstringURL to scrapeyes
refresh_intervaldurationHow often to refresh targets."60s"no


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

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 filesystem.

Each target includes the following labels:

  • __meta_url: URL the target was obtained from.

Component health

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

Debug information

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

Debug metrics

  • prometheus_sd_http_failures_total (counter): Total number of refresh failures.


This example will query a url every 15 seconds and expose targets that it finds:

discovery.http "dynamic_targets" {
  url = ""
  refresh_interval = "15s"