hashicorp/nomad · error

nil HTTP client transport

Error message

nil HTTP client transport

What it means

Guard error in cloneWithTimeout: fires when the supplied *http.Client has a nil Transport, so the function cannot clone the transport to apply dial timeouts. Typically the client was hand-built without an explicit Transport.

Source

Thrown at api/api.go:400

	}
	if v := os.Getenv("NOMAD_SKIP_VERIFY"); v != "" {
		if insecure, err := strconv.ParseBool(v); err == nil {
			config.TLSConfig.Insecure = insecure
		}
	}
	if v := os.Getenv("NOMAD_TOKEN"); v != "" {
		config.SecretID = v
	}
	return config
}

// cloneWithTimeout returns a cloned httpClient with set timeout if positive;
// otherwise, returns the same client
func cloneWithTimeout(httpClient *http.Client, t time.Duration) (*http.Client, error) {
	if httpClient == nil {
		return nil, errors.New("nil HTTP client")
	} else if httpClient.Transport == nil {
		return nil, errors.New("nil HTTP client transport")
	}

	if t.Nanoseconds() < 0 {
		return httpClient, nil
	}

	tr, ok := httpClient.Transport.(*http.Transport)
	if !ok {
		return nil, fmt.Errorf("unexpected HTTP transport: %T", httpClient.Transport)
	}

	// copy all public fields, to avoid copying transient state and locks
	ntr := &http.Transport{
		Proxy:                  tr.Proxy,
		DialContext:            tr.DialContext,
		Dial:                   tr.Dial,
		DialTLS:                tr.DialTLS,
		TLSClientConfig:        tr.TLSClientConfig,

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Set an explicit Transport (e.g. &http.Transport{}) on the http.Client passed in Config.HTTPClient
2. Use api.DefaultConfig() which sets a proper transport

When it happens

Trigger: Thrown at api/api.go:400 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/940673fc4dcc11af. Report an issue: GitHub.