Documentation Grafana Agent Flow mode Reference Components reference otelcol.processor.discovery

otelcol.processor.discovery

otelcol.processor.discovery accepts traces telemetry data from other otelcol components. It can be paired with discovery.* components, which supply a list of labels for each discovered target. otelcol.processor.discovery adds resource attributes to spans which have a hostname matching the one in the __address__ label provided by the discovery.* component.

Multiple otelcol.processor.discovery components can be specified by giving them different labels.

Usage

river Copy

otelcol.processor.discovery "LABEL" {
  targets = [...]
  output {
    traces  = [...]
  }
}

Arguments

otelcol.processor.discovery supports the following arguments:

targets could come from discovery.* components:

1. The __address__ label will be matched against the IP address of incoming spans.
   • If __address__ contains a port, it is ignored.
2. If a match is found, then relabeling rules are applied.
   • Note that labels starting with __ will not be added to the spans.

The supported values for operation_type are:

• insert: Inserts a new resource attribute if the key does not already exist.
• update: Updates a resource attribute if the key already exists.
• upsert: Either inserts a new resource attribute if the key does not already exist, or updates a resource attribute if the key does exist.

The supported values for pod_associations are:

• ip: The hostname will be sourced from an ip resource attribute.
• net.host.ip: The hostname will be sourced from a net.host.ip resource attribute.
• k8s.pod.ip: The hostname will be sourced from a k8s.pod.ip resource attribute.
• hostname: The hostname will be sourced from a host.name resource attribute.
• connection: The hostname will be sourced from the context from the incoming requests (gRPC and HTTP).

If multiple pod_associations methods are enabled, the order of evaluation is honored. For example, when pod_associations is ["ip", "net.host.ip"], "net.host.ip" may be matched only if "ip" has not already matched.

Blocks

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

output block

Exported fields

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

input accepts otelcol.Consumer OTLP-formatted data for telemetry signals of these types:

• traces

Component health

otelcol.processor.discovery is only reported as unhealthy if given an invalid configuration.

Debug information

otelcol.processor.discovery does not expose any component-specific debug information.

Examples

Basic usage

river Copy

discovery.http "dynamic_targets" {
    url              = "https://example.com/scrape_targets"
    refresh_interval = "15s"
}

otelcol.processor.discovery "default" {
    targets = discovery.http.dynamic_targets.targets

    output {
        traces = [otelcol.exporter.otlp.default.input]
    }
}

Using more than one discovery process

Outputs from more than one discovery process can be combined via the concat function.

river Copy

discovery.http "dynamic_targets" {
    url              = "https://example.com/scrape_targets"
    refresh_interval = "15s"
}

discovery.kubelet "k8s_pods" {
  bearer_token_file = "/var/run/secrets/kubernetes.io/serviceaccount/token"
  namespaces        = ["default", "kube-system"]
}

otelcol.processor.discovery "default" {
    targets = concat(discovery.http.dynamic_targets.targets, discovery.kubelet.k8s_pods.targets)

    output {
        traces = [otelcol.exporter.otlp.default.input]
    }
}

Using a preconfigured list of attributes

It is not necessary to use a discovery component. In the example below, both a test_label and a test.label.with.dots resource attributes will be added to a span if its IP address is “1.2.2.2”. The __internal_label__ will be not be added to the span, because it begins with a double underscore (__).

river Copy

otelcol.processor.discovery "default" {
    targets = [{
        "__address__"          = "1.2.2.2", 
        "__internal_label__"   = "test_val",
        "test_label"           = "test_val2",
        "test.label.with.dots" = "test.val2.with.dots"}]

    output {
        traces = [otelcol.exporter.otlp.default.input]
    }
}

Compatible components

otelcol.processor.discovery can accept arguments from the following components:

• Components that export Targets
• Components that export OpenTelemetry otelcol.Consumer

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

• Components that consume OpenTelemetry otelcol.Consumer