[DOCS-15273] Add OpenTelemetry metrics destination

config/_default/menus/main.en.yaml

@@ -7051,31 +7051,36 @@ menu:
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_opensearch
       weight: 420
+    - name: OpenTelemetry
+      url: observability_pipelines/destinations/opentelemetry
+      parent: observability_pipelines_destinations
+      identifier: observability_pipelines_destinations_opentelemetry
+      weight: 421
     - name: SentinelOne
       url: observability_pipelines/destinations/sentinelone
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_sentinelone
-      weight: 421
+      weight: 422
     - name: Socket
       url: observability_pipelines/destinations/socket
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_socket
-      weight: 422
+      weight: 423
     - name: Splunk HEC
       url: observability_pipelines/destinations/splunk_hec/logs/
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_splunk_hec
-      weight: 423
+      weight: 424
     - name: Sumo Logic Hosted Collector
       url: observability_pipelines/destinations/sumo_logic_hosted_collector
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_sumo_logic_hosted_collector
-      weight: 424
+      weight: 425
     - name: Syslog
       url: observability_pipelines/destinations/syslog
       parent: observability_pipelines_destinations
       identifier: observability_pipelines_syslog
-      weight: 425
+      weight: 426
     - name: Packs
       url: observability_pipelines/packs/
       parent: observability_pipelines

content/en/observability_pipelines/destinations/_index.md

@@ -77,12 +77,14 @@ These are the available destinations:
 - [Datadog Metrics][1]
 - [Elasticsearch][2]
 - [HTTP/S Client][3]
+- [OpenTelemetry][5]
 - [Splunk HEC][4]
 
 [1]: /observability_pipelines/destinations/datadog_metrics/
 [2]: /observability_pipelines/destinations/elasticsearch/
 [3]: /observability_pipelines/destinations/http_client/
 [4]: /observability_pipelines/destinations/splunk_hec/metrics
+[5]: /observability_pipelines/destinations/opentelemetry/
 
 {{% /tab %}}
 {{< /tabs >}}

content/en/observability_pipelines/destinations/opentelemetry.md

@@ -0,0 +1,93 @@
+---
+title: OpenTelemetry Destination
+disable_toc: false
+products:
+- name: Metrics
+  icon: metrics
+  url: /observability_pipelines/configuration/?tab=metrics#pipeline-types
+---
+
+{{< product-availability >}}
+
+## Overview
+
+Use Observability Pipelines' OpenTelemetry destination to send metrics over HTTP/S to an OpenTelemetry (OTEL) Collector or another OpenTelemetry Protocol (OTLP)-compatible endpoint.
+
+## Set up destination
+
+<div class="alert alert-danger">For Secrets Management: Only enter the identifier for the HTTP/S Client URI and, if applicable, the TLS key pass. Do <b>not</b> enter the actual values.</div>
+
+Configure the OpenTelemetry destination when you [set up a pipeline][3]. You can set up a pipeline in the [UI][1], using the [API][4], or with [Terraform][5]. The steps in this section are configured in the UI.
+
+After you select the OpenTelemetry destination in the pipeline UI, enter the identifier for your HTTP/S Client URI. If you leave it blank, the [default](#secret-defaults) is used.
+
+**Notes**:
+- The Worker can only send counter, gauge, and histogram metrics to OpenTelemetry. OpenTelemetry does not support other metrics types so the Worker drops them. See [Filter out unsupported metrics](#filter-out-unsupported-metrics) for more information.
+- If you are sending your metrics to a Prometheus OTLP receiver, set your OTLP receiver to allow out-of-order samples. Otherwise, the Prometheus OTLP receiver rejects the out of order sample and the Worker logs a bad request error and drops the batch of metrics.
+- If you enter secret identifiers and then choose to use environment variables, the environment variable is the identifier entered and prepended with `DD_OP_`. For example, if you entered `PASSWORD_1` for a password identifier, the environment variable for that password is `DD_OP_PASSWORD_1`.
+
+### Optional settings
+
+#### Enable TLS
+
+{{% observability_pipelines/tls_settings %}}
+
+#### Buffering
+
+{{% observability_pipelines/destination_buffer %}}
+
+## Filter out unsupported metrics
+
+The Worker can only send counter, gauge, and histogram metrics to OpenTelemetry. The following Datadog metrics are not supported because they cannot be converted to OTLP format:
+
+- StatsD-type metrics
+- Distribution metrics
+- Sketch metrics
+
+If one of these metrics is in a batch to be encoded and sent to OpenTelemetry, the Worker drops the unsupported metric, logs an error, and updates the `component_error_total` metric. Datadog recommends using a [filter processor][9] to filter out unsupported metric types.
+
+## Secret defaults
+
+{{% observability_pipelines/set_secrets_intro %}}
+
+{{< tabs >}}
+{{% tab "Secrets Management" %}}
+
+- HTTP/S Client URI endpoint identifier
+  - References the HTTP/S URI endpoint to which the Worker sends OpenTelemetry data. For example: `http://localhost:4319/v1/metrics`.
+  - The default identifier is `DESTINATION_OTEL_HTTP_CLIENT_URI`.
+- HTTP/S Client TLS passphrase identifier (when TLS is enabled):
+	- The default identifier is `DESTINATION_OTEL_HTTP_CLIENT_KEY_PASS`.
+
+{{% /tab %}}
+
+{{% tab "Environment Variables" %}}
+
+{{% observability_pipelines/configure_existing_pipelines/destination_env_vars/opentelemetry %}}
+
+{{% /tab %}}
+{{< /tabs >}}
+
+## Metrics
+
+For [component metrics][6] and [destination buffer metrics][7] emitted by all destinations, see the [Pipelines Usage Metrics][8] documentation. To filter or group by OpenTelemetry destination metrics, use the tag `component_type:opentelemetry`.
+
+## How the destination works
+
+### Event batching
+
+A batch of events is flushed when one of these conditions occurs. See [event batching][2] for more information.
+
+| Maximum Events | Maximum Size (MB) | Timeout (seconds)   |
+|----------------|-------------------|---------------------|
+| TKTK           | TKTK              | TKTK                |
+
+[1]: https://app.datadoghq.com/observability-pipelines
+[2]: /observability_pipelines/destinations/#event-batching
+[3]: /observability_pipelines/configuration/set_up_pipelines/
+[4]: /api/latest/observability-pipelines/
+[5]: https://registry.terraform.io/providers/datadog/datadog/latest/docs/resources/observability_pipeline
+[6]: /observability_pipelines/monitoring_and_troubleshooting/pipeline_usage_metrics/#component-metrics
+[7]: /observability_pipelines/monitoring_and_troubleshooting/pipeline_usage_metrics/#destination-buffer-metrics
+[8]: /observability_pipelines/monitoring_and_troubleshooting/pipeline_usage_metrics/
+[9]: /observability_pipelines/processors/filter/

content/en/observability_pipelines/guide/environment_variables.md

@@ -125,6 +125,9 @@ Some Observability Pipelines components require setting up environment variables
 ### OpenSearch
 {{% observability_pipelines/configure_existing_pipelines/destination_env_vars/opensearch %}}
 
+### OpenTelemetry
+{{% observability_pipelines/configure_existing_pipelines/destination_env_vars/opentelemetry %}}
+
 ### SentinelOne
 {{% observability_pipelines/configure_existing_pipelines/destination_env_vars/sentinelone %}}
 

layouts/shortcodes/observability_pipelines/configure_existing_pipelines/destination_env_vars/opentelemetry.md

@@ -0,0 +1,5 @@
+- HTTP/S client URI endpoint:
+	- The HTTP/S URI endpoint to which the Worker sends OpenTelemetry data. For example: `http://localhost:4319/v1/metrics`.
+	- The default environment variable is `DD_OP_DESTINATION_OTEL_HTTP_CLIENT_URI`.
+- HTTP/S Client TLS passphrase (when enabled):
+	- The default environment variable is `DD_OP_DESTINATION_OTEL_HTTP_CLIENT_KEY_PASS`.