`declare`

declare is an optional configuration block used to define a new custom component. declare blocks must be given a label that determines the name of the custom component.

Usage

declare "<COMPONENT_NAME>" {
    <COMPONENT_DEFINITION>
}

Arguments

The declare block has no predefined schema for its arguments. The body of the declare block is used as the component definition. The body can contain the following:

argument blocks
export blocks
declare blocks
import blocks
Component definitions (either built-in or custom components)

The declare block may not contain any configuration blocks that aren’t listed above.

Exported fields

The declare block has no predefined schema for its exports. The fields exported by the declare block are determined by the export blocks found in its definition.

Example

This example creates and uses a custom component that self-collects process metrics and forwards them to an argument specified by the user of the custom component:

declare "self_collect" {
  argument "metrics_output" {
    optional = false
    comment  = "Where to send collected metrics."
  }

  prometheus.scrape "selfmonitor" {
    targets = [{
      __address__ = "127.0.0.1:12345",
    }]

    forward_to = [argument.metrics_output.value]
  }
}

self_collect "example" {
  metrics_output = prometheus.remote_write.example.receiver
}

prometheus.remote_write "example" {
  endpoint {
    url = <REMOTE_WRITE_URL>
  }
}