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Caution

Grafana Alloy is the new name for our distribution of the OTel collector. Grafana Agent has been deprecated and is in Long-Term Support (LTS) through October 31, 2025. Grafana Agent will reach an End-of-Life (EOL) on November 1, 2025. Read more about why we recommend migrating to Grafana Alloy.

Important: This documentation is about an older version. It's relevant only to the release noted, many of the features and functions have been updated or replaced. Please view the current version.

Beta

module.string (deprecated)

Caution

Starting with release v0.40, module.string is deprecated and is replaced by import.string. module.string will be removed in a future release.

BETA: This is a beta component. Beta components are subject to breaking changes, and may be replaced with equivalent functionality that cover the same use case.

module.string is a module loader component. A module loader is a Grafana Agent Flow component which retrieves a module and runs the components defined inside of it.

Usage

river
module.string "LABEL" {
  content = CONTENT

  arguments {
    MODULE_ARGUMENT_1 = VALUE_1
    MODULE_ARGUMENT_2 = VALUE_2
    ...
  }
}

Arguments

The following arguments are supported:

NameTypeDescriptionDefaultRequired
contentsecret or stringThe contents of the module to load as a secret or string.yes

content is a string that contains the configuration of the module to load. content is typically loaded by using the exports of another component. For example,

  • local.file.LABEL.content
  • remote.http.LABEL.content
  • remote.s3.LABEL.content

Blocks

The following blocks are supported inside the definition of module.string:

HierarchyBlockDescriptionRequired
argumentsargumentsArguments to pass to the module.no

arguments block

The arguments block specifies the list of values to pass to the loaded module.

The attributes provided in the arguments block are validated based on the argument blocks defined in the module source:

  • If a module source marks one of its arguments as required, it must be provided as an attribute in the arguments block of the module loader.

  • Attributes in the argument block of the module loader will be rejected if they are not defined in the module source.

Exported fields

The following fields are exported and can be referenced by other components:

NameTypeDescription
exportsmap(any)The exports of the Module loader.

exports exposes the export config block inside a module. It can be accessed from the parent config via module.string.LABEL.exports.EXPORT_LABEL.

Values in exports correspond to export blocks defined in the module source.

Component health

module.string is reported as healthy if the most recent load of the module was successful.

If the module is not loaded successfully, the current health displays as unhealthy and the health includes the error from loading the module.

Debug information

module.string does not expose any component-specific debug information.

Debug metrics

module.string does not expose any component-specific debug metrics.

Example

In this example, we pass credentials from a parent config to a module which loads a prometheus.remote_write component. The exports of the prometheus.remote_write component are exposed to parent config, allowing the parent config to pass metrics to it.

Parent:

river
local.file "metrics" {
  filename = "/path/to/prometheus_remote_write_module.river"
}

module.string "metrics" {
  content = local.file.metrics.content

  arguments {
    username = env("PROMETHEUS_USERNAME")
    password = env("PROMETHEUS_PASSWORD")
  }
}

prometheus.exporter.unix "default" { }

prometheus.scrape "local_agent" {
  targets         = prometheus.exporter.unix.default.targets
  forward_to      = [module.string.metrics.exports.prometheus_remote_write.receiver]
  scrape_interval = "10s"
}

Module:

river
argument "username" { }

argument "password" { }

export "prometheus_remote_write" {
  value = prometheus.remote_write.grafana_cloud
}

prometheus.remote_write "grafana_cloud" {
  endpoint {
    url = "https://prometheus-us-central1.grafana.net/api/prom/push"

    basic_auth {
      username = argument.username.value
      password = argument.password.value
    }
  }
}