Converting OpenTelemetry Resource Attributes to Host Tags when sending resources to the Datadog Agent OTLP Receiver

[NassimBtk]

Description:

I am currently working with the OpenTelemetry Collector, sending several Host resources and metrics to the Datadog Agent via the OTLP receiver. I need to attach resource attributes (e.g., env, service) as host tags in Datadog.

DataDog Agent Config:

otlp_config:
  receiver:
    protocols:
      http:
        endpoint: 0.0.0.0:4318
   metrics:
    resource_attributes_as_tags: true

OpenTelemetry Collector Config:

receivers:
  otlp:
    protocols:
      grpc:
        endpoint: localhost:4317
processors:
  transform:
    metric_statements:
      - context: resource
        statements:
          - set(attributes["datadog.host.use_as_metadata"], true)
 # ...
 exporters:
  otlphttp/datadog-agent:
    endpoint: http://localhost:4318

service:
  telemetry:
  extensions: [health_check]
  pipelines:
    metrics:
      receivers: [otlp]
      processors: [transform, memory_limiter, batch]
      exporters: [otlphttp/datadog-agent] # Datadog listed here

Is there a way to configure the Datadog Agent to automatically convert OpenTelemetry each resource attributes into host-level tags that can be applied to the infrastructure hosts? If so, what configuration changes are needed in either the OpenTelemetry Collector or the Datadog Agent?

Thanks!

[pablo-spinelli]

Hi there! Happy new year! qq, were you able to fix that because I have the same problem.... thank you!!

[NassimBtk]

Hello! Happy new year!
Yes, we were able to get OTEL resource attributes populated in Datadog as host tags. Here’s what worked for us:

• We populate host tags by setting resource attributes prefixed with datadog.host.tag. (e.g., datadog.host.tag.env).
  Datadog documents this here: OTLP resource attributes.

  If you can’t set these attributes from the app/source, you can add or rewrite them in the Collector using a resource processor, or use the transform processor with OTTL for more advanced logic.

• We set datadog.host.use_as_metadata to true on all payloads that represent host resources (so Datadog treats them as host metadata):

  processors:
    transform:
      metric_statements:
        - context: resource
          statements:
            - set(attributes["datadog.host.use_as_metadata"], true)

  Datadog documents this here: Host metadata.

• We send the metrics using the Datadog Exporter instead of sending OTLP directly to the Agent.

  exporters:
    datadog/api:
      api:
        key: "********" # Datadog API Key
        # site: datadoghq.eu # Uncomment and update if required
      host_metadata:
        enabled: true
        reporter_period: 5m # should be >= 5 minutes
      metrics:
        resource_attributes_as_tags: true

  We enable host_metadata with a reporter_period of 5 minutes so that metadata (including host tags) are reported periodically to Datadog.