grafana/k6 · error

lookup %s: no such host

Error message

lookup %s: no such host

What it means

Raised by Dialer.findRemote when DNS resolution returns neither an error nor an IP for the requested host — the hostname simply does not exist. It mirrors Go's net.DNS "no such host" error shape for hosts configured through k6's network layer.

Source

Thrown at lib/netext/dialer.go:164

	if d.Hosts != nil {
		remote, e := d.getConfiguredHost(addr, host, port)
		if e != nil || remote != nil {
			return remote, e
		}
	}

	if ip != nil {
		return types.NewHost(ip, port)
	}

	ip, err = d.Resolver.LookupIP(host)
	if err != nil {
		return nil, err
	}

	if ip == nil {
		return nil, fmt.Errorf("lookup %s: no such host", host)
	}

	return types.NewHost(ip, port)
}

func (d *Dialer) getConfiguredHost(addr, host, port string) (*types.Host, error) {
	if remote := d.Hosts.Match(addr); remote != nil {
		return remote, nil
	}

	if remote := d.Hosts.Match(host); remote != nil {
		if remote.Port != 0 || port == "" {
			return remote, nil
		}

		newPort, err := strconv.Atoi(port)
		if err != nil {
			return nil, err

View on GitHub (pinned to 01ffac6f24)

Solutions

1. Verify the hostname is spelled correctly in the script
2. Check DNS resolution from the machine running k6 (e.g. nslookup)
3. Map the hostname to an IP via the --host (hosts) option if it should be overridden
4. Ensure the DNS policy in K6_DNS is not blocking the lookup

When it happens

Trigger: Thrown at lib/netext/dialer.go:164 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/be901e232012ea23. Report an issue: GitHub.