chore(docs): missing documentation for nodes_stats_summary (#424)

Signed-off-by: Marc Nuri <[email protected]>

Author: manusa

README.md

@@ -249,6 +249,9 @@ In case multi-cluster support is enabled (default) and you have access to multip
   - `query` (`string`) **(required)** - query specifies services(s) or files from which to return logs (required). Example: "kubelet" to fetch kubelet logs, "/<log-file-name>" to fetch a specific log file from the node (e.g., "/var/log/kubelet.log" or "/var/log/kube-proxy.log")
   - `tailLines` (`integer`) - Number of lines to retrieve from the end of the logs (Optional, 0 means all logs)
 
+- **nodes_stats_summary** - Get detailed resource usage statistics from a Kubernetes node via the kubelet's Summary API. Provides comprehensive metrics including CPU, memory, filesystem, and network usage at the node, pod, and container levels. On systems with cgroup v2 and kernel 4.20+, also includes PSI (Pressure Stall Information) metrics that show resource pressure for CPU, memory, and I/O. See https://kubernetes.io/docs/reference/instrumentation/understand-psi-metrics/ for details on PSI metrics
+  - `name` (`string`) **(required)** - Name of the node to get stats from
+
 - **pods_list** - List all the Kubernetes pods in the current cluster from all namespaces
   - `labelSelector` (`string`) - Optional Kubernetes label selector (e.g. 'app=myapp,env=prod' or 'app in (myapp,yourapp)'), use this option when you want to filter the pods by label
 

pkg/kubernetes/nodes.go

@@ -39,6 +39,7 @@ func (k *Kubernetes) NodesLog(ctx context.Context, name string, query string, ta
 
 func (k *Kubernetes) NodesStatsSummary(ctx context.Context, name string) (string, error) {
 	// Use the node proxy API to access stats summary from the kubelet
+	// https://kubernetes.io/docs/reference/instrumentation/understand-psi-metrics/
 	// This endpoint provides CPU, memory, filesystem, and network statistics
 
 	req, err := k.AccessControlClientset().NodesStatsSummary(ctx, name)