grafana/k6 · error

failed to read response body: %w

Error message

failed to read response body: %w

What it means

extractSecretFromResponse reads the HTTP response through an io.LimitReader capped at 24 KiB (maxSecretSize) to bound memory use; io.ReadAll failed here (e.g. connection reset mid-body or read timeout). The secret cannot be extracted and Get fails.

Source

Thrown at internal/secretsource/url/url.go:241

func newLimiter(requestsPerMinuteLimit, requestsBurst int) *rate.Limiter {
	// The calculation below looks wrong because it seems like it's giving
	// n min²/req, but the first number is actually time unit/min, so the
	// units of the result are time unit/req, which is correct because it's
	// the interval of time after which a new token is replenished. In
	// other words, the units are time unit/token.
	tokenReplenishInterval := time.Minute / time.Duration(requestsPerMinuteLimit)

	return rate.NewLimiter(rate.Every(tokenReplenishInterval), requestsBurst)
}

func extractSecretFromResponse(body io.Reader, responsePath string) (string, error) {
	const maxSecretSize = 24 * 1024

	// Limit reading to prevent memory exhaustion from large responses
	limitedReader := io.LimitReader(body, maxSecretSize+1)
	data, err := io.ReadAll(limitedReader)
	if err != nil {
		return "", fmt.Errorf("failed to read response body: %w", err)
	}

	if len(data) > maxSecretSize {
		return "", fmt.Errorf("secret response exceeds maximum size of %d bytes", maxSecretSize)
	}

	if responsePath == "" {
		// If no path specified, assume response body is the secret
		return string(data), nil
	}

	result := gjson.GetBytes(data, responsePath)

	if !result.Exists() {
		return "", fmt.Errorf("path %q not found in response", responsePath)
	}

	if result.Type != gjson.String {

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Retry the secret fetch; mid-body read failures are typically transient network issues
2. Check service stability and network connectivity to the secret endpoint

When it happens

Trigger: Thrown at internal/secretsource/url/url.go:241 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of grafana/k6@01ffac6f24 (2026-08-18). Data as JSON: /api/errors/ff0f61c15847a04e. Report an issue: GitHub.