DocumentationGrafana AgentFlow modeReferenceConfiguration blocksdeclare

declare block

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.

Example

river Copy

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 may contain:

• 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 are not 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:

river Copy

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
  }
}