Kubernetes z-pages

Provides runtime diagnostics for Kubernetes components, offering insights into component runtime status and configuration flags.
FEATURE STATE: Kubernetes v1.32 [alpha]

Kubernetes core components can expose a suite of z-endpoints to make it easier for users to debug their cluster and its components. These endpoints are strictly to be used for human inspection to gain real time debugging information of a component binary. Avoid automated scraping of data returned by these endpoints; in Kubernetes 1.35 these are an alpha feature and the response format may change in future releases.

z-pages

Kubernetes v1.35 allows you to enable z-pages to help you troubleshoot problems with its core control plane components. These special debugging endpoints provide internal information about running components. For Kubernetes 1.35, components serve the following endpoints (when enabled):

statusz

Enabled using the ComponentStatusz feature gate, the /statusz endpoint displays high level information about the component such as its Kubernetes version, emulation version, start time and more.

The /statusz plain text response from the API server is similar to:

kube-apiserver statusz
Warning: This endpoint is not meant to be machine parseable, has no formatting compatibility guarantees and is for debugging purposes only.

Started: Wed Oct 16 21:03:43 UTC 2024
Up: 0 hr 00 min 16 sec
Go version: go1.23.2
Binary version: 1.32.0-alpha.0.1484+5eeac4f21a491b-dirty
Emulation version: 1.32.0-alpha.0.1484
Paths: /healthz /livez /metrics /readyz /statusz /version

statusz (structured)

FEATURE STATE: Kubernetes v1.32 [alpha](disabled by default)

Starting with Kubernetes v1.35, the /statusz endpoint supports a structured, versioned response format when requested with the appropriate Accept header. Without an Accept header, the endpoint returns the plain text response format by default.

To request the structured response, use:

Accept: application/json;v=v1alpha1;g=config.k8s.io;as=Statusz

Example structured response:

{
  "kind": "Statusz",
  "apiVersion": "config.k8s.io/v1alpha1",
  "metadata": {
    "name": "kube-apiserver"
  },
  "startTime": "2025-10-29T00:30:01Z",
  "uptimeSeconds": 856,
  "goVersion": "go1.23.2",
  "binaryVersion": "1.35.0",
  "emulationVersion": "1.35",
  "paths": [
    "/healthz",
    "/livez",
    "/metrics",
    "/readyz",
    "/statusz",
    "/version"
  ]
}

The config.k8s.io/v1alpha1 schema for the structured /statusz response is as follows:

// Statusz is the config.k8s.io/v1alpha1 schema for the /statusz endpoint.
type Statusz struct {
	// Kind is "Statusz".
	Kind string `json:"kind"`
	// APIVersion is the version of the object, e.g., "config.k8s.io/v1alpha1".
	APIVersion string `json:"apiVersion"`
	// Standard object's metadata.
	// +optional
	Metadata metav1.ObjectMeta `json:"metadata,omitempty"`
	// StartTime is the time the component process was initiated.
	StartTime metav1.Time `json:"startTime"`
	// UptimeSeconds is the duration in seconds for which the component has been running continuously.
	UptimeSeconds int64 `json:"uptimeSeconds"`
	// GoVersion is the version of the Go programming language used to build the binary.
	// The format is not guaranteed to be consistent across different Go builds.
	// +optional
	GoVersion string `json:"goVersion,omitempty"`
	// BinaryVersion is the version of the component's binary.
	// The format is not guaranteed to be semantic versioning and may be an arbitrary string.
	BinaryVersion string `json:"binaryVersion"`
	// EmulationVersion is the Kubernetes API version which this component is emulating.
	// if present, formatted as "<major>.<minor>"
	// +optional
	EmulationVersion string `json:"emulationVersion,omitempty"`
	// MinimumCompatibilityVersion is the minimum Kubernetes API version with which the component is designed to work.
	// if present, formatted as "<major>.<minor>"
	// +optional
	MinimumCompatibilityVersion string `json:"minimumCompatibilityVersion,omitempty"`
	// Paths contains relative URLs to other essential read-only endpoints for debugging and troubleshooting.
	// +optional
	Paths []string `json:"paths,omitempty"`
}

flagz

Enabled using the ComponentFlagz feature gate, the /flagz endpoint shows you the command line arguments that were used to start a component.

The /flagz plain text response from the API server looks something like:

kube-apiserver flags
Warning: This endpoint is not meant to be machine parseable, has no formatting compatibility guarantees and is for debugging purposes only.

advertise-address=192.168.8.2
contention-profiling=false
enable-priority-and-fairness=true
profiling=true
authorization-mode=[Node,RBAC]
authorization-webhook-cache-authorized-ttl=5m0s
authorization-webhook-cache-unauthorized-ttl=30s
authorization-webhook-version=v1beta1
default-watch-cache-size=100

flagz (structured)

FEATURE STATE: Kubernetes v1.32 [alpha](disabled by default)

Starting with Kubernetes v1.35, the /flagz endpoint supports a structured, versioned response format when requested with the appropriate Accept header. Without an Accept header, the endpoint returns the plain text response format by default.

To request the structured response, use:

Accept: application/json;v=v1alpha1;g=config.k8s.io;as=Flagz

Example structured response:

{
  "kind": "Flagz",
  "apiVersion": "config.k8s.io/v1alpha1",
  "metadata": {
    "name": "kube-apiserver"
  },
  "flags": {
    "advertise-address": "192.168.8.4",
    "allow-privileged": "true",
    "anonymous-auth": "true",
    "authorization-mode": "[Node,RBAC]",
    "enable-priority-and-fairness": "true",
    "profiling": "true",
    "default-watch-cache-size": "100"
  }
}

The config.k8s.io/v1alpha1 schema for the structured /flagz response is as follows:

// Flagz is the config.k8s.io/v1alpha1 schema for the /flagz endpoint.
type Flagz struct {
	// Kind is "Flagz".
	Kind string `json:"kind"`
	// APIVersion is the version of the object, e.g., "config.k8s.io/v1alpha1".
	APIVersion string `json:"apiVersion"`
	// Standard object's metadata.
	// +optional
	Metadata metav1.ObjectMeta `json:"metadata,omitempty"`
	// Flags contains the command-line flags and their values.
	// The keys are the flag names and the values are the flag values,
	// possibly with confidential values redacted.
	// +optional
	Flags map[string]string `json:"flags,omitempty"`
}
Last modified October 15, 2025 at 9:38 AM PST: zpages structured response (63cc27b920)