kubernetes/kops · error

getting http client: %w

Error message

getting http client: %w

What it means

After obtaining the REST config, RunRollingUpdateCluster builds an HTTP client and a Kubernetes clientset with f.HTTPClient and kubernetes.NewForConfigAndClient. This error wraps a failure of f.HTTPClient(restConfig) — the HTTP transport for talking to the cluster API server could not be constructed (bad TLS material in the config, unsupported proxy/transport settings, or invalid CA/cert data).

Source

Thrown at cmd/kops/rolling-update_cluster.go:258

		return err
	}

	cluster, err := GetCluster(ctx, f, options.ClusterName)
	if err != nil {
		return err
	}

	var nodes []v1.Node
	var k8sClient kubernetes.Interface
	if !options.CloudOnly {
		restConfig, err := f.RESTConfig(ctx, cluster, options.CreateKubecfgOptions)
		if err != nil {
			return fmt.Errorf("getting rest config: %w", err)
		}

		httpClient, err := f.HTTPClient(restConfig)
		if err != nil {
			return fmt.Errorf("getting http client: %w", err)
		}

		k8sClient, err = kubernetes.NewForConfigAndClient(restConfig, httpClient)
		if err != nil {
			return fmt.Errorf("getting kubernetes client: %w", err)
		}

		nodeList, err := k8sClient.CoreV1().Nodes().List(ctx, metav1.ListOptions{})
		if err != nil {
			fmt.Fprintf(os.Stderr, "Unable to reach the kubernetes API.\n")
			fmt.Fprintf(os.Stderr, "Use --cloudonly to do a rolling-update without confirming progress with the k8s API\n\n")
			return fmt.Errorf("error listing nodes in cluster: %v", err)
		}

		if nodeList != nil {
			nodes = nodeList.Items
		}
	}

View on GitHub (pinned to 4c8573c808)

Solutions

1. Read the wrapped error; validate the kubeconfig TLS blocks (`openssl x509 -in ca.crt -noout`) to rule out corrupt certs.
2. Unset/fix HTTP(S)_PROXY / NO_PROXY env vars and retry.
3. Re-export a fresh kubeconfig: `kops export kubecfg <cluster> --admin` to regenerate clean cert/CA data.
4. Simplify any custom rest-config options passed via --create-kubecfg-flags and retry with defaults.

// Sanity-check TLS material before building the client
cfg, err := f.RESTConfig(ctx, cluster, opts)
if err != nil { return err }
for _, ca := range cfg.CAData {
    if _, err := x509.ParseCertificate(ca); err != nil {
        return fmt.Errorf("corrupt CA data in rest config: %v", err)
    }
}

if strings.Contains(err.Error(), "getting http client") {
    // TLS/proxy issue: clear proxy env, re-export kubeconfig, retry once
    os.Unsetenv("HTTPS_PROXY"); os.Unsetenv("HTTP_PROXY")
    exec.Command("kops", "export", "kubecfg", clusterName, "--admin").Run()
    return runRollingUpdate(...)
}

When it happens

Trigger: The REST config assembled in the previous step contains invalid TLS data (corrupt CA bundle or client cert), malformed proxy environment variables (HTTP_PROXY/HTTPS_PROXY), or incompatible transport options from CreateKubecfgOptions, causing client.HTTPClient to fail.

Common situations: Truncated or corrupted kubeconfig certificates (bad base64 in kubeconfig); corporate proxy misconfiguration via env vars; custom CA settings passed through CreateKubecfgOptions that don't parse; Go version / client-go TLS incompatibilities on the machine running kops.

Related errors

• getting rest config: %w
• building kube client: %w
• cannot build kube client: %w
• cannot create cluster validator: %v
• building kubernetes client: %w

AI-assisted analysis of kubernetes/kops@4c8573c808 (2026-09-05). Data as JSON: /api/errors/c9a50f592b7f1d42. Report an issue: GitHub.