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discovery.eureka

discovery.eureka discovers instances in a Eureka Registry and exposes them as targets.

Usage

river
discovery.eureka "LABEL" {
    server = SERVER
}

Arguments

The following arguments are supported:

NameTypeDescriptionDefaultRequired
serverstringEureka server URL.yes
refresh_intervaldurationInterval at which to refresh the list of targets.30sno
enable_http2boolWhether HTTP2 is supported for requests.trueno
bearer_tokensecretBearer token to authenticate with.no
bearer_token_filestringFile containing a bearer token to authenticate with.no
proxy_urlstringHTTP proxy to proxy requests through.no
follow_redirectsboolWhether redirects returned by the server should be followed.trueno

At most one of the following can be provided:

Blocks

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

HierarchyBlockDescriptionRequired
basic_authbasic_authConfigure basic_auth for authenticating to the endpoint.no
authorizationauthorizationConfigure generic authorization to the endpoint.no
oauth2oauth2Configure OAuth2 for authenticating to the endpoint.no
oauth2 > tls_configtls_configConfigure TLS settings for connecting to the endpoint.no
tls_configtls_configConfigure 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

NameTypeDescriptionDefaultRequired
password_filestringFile containing the basic auth password.no
passwordsecretBasic auth password.no
usernamestringBasic auth username.no

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

authorization block

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

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

oauth2 block

NameTypeDescriptionDefaultRequired
client_idstringOAuth2 client ID.no
client_secret_filestringFile containing the OAuth2 client secret.no
client_secretsecretOAuth2 client secret.no
endpoint_paramsmap(string)Optional parameters to append to the token URL.no
proxy_urlstringOptional proxy URL for OAuth2 requests.no
scopeslist(string)List of scopes to authenticate with.no
token_urlstringURL 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

NameTypeDescriptionDefaultRequired
ca_pemstringCA PEM-encoded text to validate the server with.no
ca_filestringCA certificate to validate the server with.no
cert_pemstringCertificate PEM-encoded text for client authentication.no
cert_filestringCertificate file for client authentication.no
insecure_skip_verifyboolDisables validation of the server certificate.no
key_filestringKey file for client authentication.no
key_pemsecretKey PEM-encoded text for client authentication.no
min_versionstringMinimum acceptable TLS version.no
server_namestringServerName 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 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:

NameTypeDescription
targetslist(map(string))The set of targets discovered from the Eureka API.

Each target includes the following labels:

  • __meta_eureka_app_name
  • __meta_eureka_app_instance_hostname
  • __meta_eureka_app_instance_homepage_url
  • __meta_eureka_app_instance_statuspage_url
  • __meta_eureka_app_instance_healthcheck_url
  • __meta_eureka_app_instance_ip_addr
  • __meta_eureka_app_instance_vip_address
  • __meta_eureka_app_instance_secure_vip_address
  • __meta_eureka_app_instance_status
  • __meta_eureka_app_instance_port
  • __meta_eureka_app_instance_port_enabled
  • __meta_eureka_app_instance_secure_port
  • __meta_eureka_app_instance_secure_port_enabled
  • __meta_eureka_app_instance_datacenterinfo_name
  • __meta_eureka_app_instance_datacenterinfo_metadata_
  • __meta_eureka_app_instance_country_id
  • __meta_eureka_app_instance_id
  • __meta_eureka_app_instance_metadata_

Component health

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

Debug information

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

Debug metrics

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

Example

river
discovery.eureka "example" {
    server = "https://eureka.example.com/eureka/v1"
}

prometheus.scrape "demo" {
  targets    = discovery.eureka.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.

Compatible components

discovery.eureka has exports that can be consumed by the following components:

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.