From ad65c24ea573a96351524d6a3529b596d3f3e13a Mon Sep 17 00:00:00 2001
From: Israel Blancas <iblancasa@gmail.com>
Date: Fri, 22 Mar 2024 16:37:35 +0100
Subject: [PATCH] TRACING-4067: add documentation for kubelet stats receiver

Signed-off-by: Israel Blancas <iblancasa@gmail.com>
---
 modules/otel-collector-components.adoc | 51 ++++++++++++++++++++++++++
 1 file changed, 51 insertions(+)

diff --git a/modules/otel-collector-components.adoc b/modules/otel-collector-components.adoc
index 9b0a27728c6f..5edf96ff6bea 100644
--- a/modules/otel-collector-components.adoc
+++ b/modules/otel-collector-components.adoc
@@ -259,6 +259,57 @@ spec:
 <5> The field selector to filter targets.
 <6> The list of namespaces to collect events from. If omitted, the default value is `+all+`.
 
+[id="kubeletstats-receiver_{context}"]
+=== Kubelet Stats Receiver
+
+:FeatureName: The Kubelet Stats Receiver
+include::snippets/technology-preview.adoc[]
+
+The Kubelet Stats Receiver extracts metrics related to nodes, pods, containers, and volumes from the kubelet's API server. These metrics are then channeled through the metrics-processing pipeline for additional analysis.
+
+.OpenTelemetry Collector custom resource with an enabled Kubelet Stats Receiver
+[source,yaml]
+----
+# ...
+config: |
+  receivers:
+    kubeletstats:
+      collection_interval: 20s
+      auth_type: "serviceAccount"
+      endpoint: "https://${env:K8S_NODE_NAME}:10250"
+      insecure_skip_verify: true
+  service:
+    pipelines:
+      metrics:
+        receivers: [kubeletstats]
+env:
+  - name: K8S_NODE_NAME # <1>
+    valueFrom:
+      fieldRef:
+        fieldPath: spec.nodeName
+# ...
+----
+<1> Sets the `K8S_NODE_NAME` to authenticate to the API.
+
+The Kubelet Stats Receiver requires additional permissions for the service account used for running the OpenTelemetry Collector.
+
+.Permissions required by the service account
+[source,yaml]
+----
+apiVersion: rbac.authorization.k8s.io/v1
+kind: ClusterRole
+metadata:
+  name: otel-collector
+rules:
+  - apiGroups: ['']
+    resources: ['nodes/stats']
+    verbs: ['get', 'watch', 'list']
+  - apiGroups: [""]
+    resources: ["nodes/proxy"] # <1>
+    verbs: ["get"]
+----
+<1> The permissions required when using the `extra_metadata_labels` or `request_utilization` or `limit_utilization` metrics.
+
 [id="prometheus-receiver_{context}"]
 === Prometheus Receiver