hashicorp/nomad · info

module %s not in %s

Error message

module %s not in %s

What it means

searchFile successfully opened and scanned the kernel metadata file but found no line matching the bridge module - the file is readable, the module just isn't listed in it. This is the expected outcome when the bridge module is neither loaded, nor built-in, nor available as a loadable module on the host. detect() aggregates it with the other probe errors and the fingerprint simply reports the node as not supporting bridge networking.

Source

Thrown at client/fingerprint/bridge_linux.go:127

	file, err := os.Open(filename)
	if err != nil {
		return fmt.Errorf("failed to open %s: %v", filename, err)
	}
	defer func() {
		_ = file.Close()
	}()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		if re.MatchString(scanner.Text()) {
			return nil // found the module!
		}
	}
	if err := scanner.Err(); err != nil {
		return fmt.Errorf("failed to scan %s: %v", filename, err)
	}

	return fmt.Errorf("module %s not in %s", module, filename)
}

View on GitHub (pinned to 482b49bf1a)

Solutions

1. Install the bridge module package for the kernel (e.g. linux-modules-extra on RHEL-family) so modules.dep lists it.
2. Load it persistently: 'sudo modprobe bridge' and add 'bridge' to /etc/modules-load.d/bridge.conf.
3. Confirm with 'grep bridge /lib/modules/$(uname -r)/modules.dep'.
4. If you don't need Nomad bridge networking mode, ignore - only nodes advertising bridge mode require the module.

Example fix

# before (module absent from all kernel metadata)
$ grep bridge /lib/modules/$(uname -r)/modules.dep
(no output)
# after
$ sudo apt-get install linux-modules-extra-$(uname -r)  # or distro equivalent
$ sudo modprobe bridge
$ grep bridge /lib/modules/$(uname -r)/modules.dep
kernel/net/bridge/bridge.ko: ...

# host preflight (shell): confirm the module is available somewhere before enabling bridge networking
# grep -q '^bridge' /proc/modules || grep -q bridge /lib/modules/$(uname -r)/modules.builtin || grep -q bridge /lib/modules/$(uname -r)/modules.dep || echo 'bridge module unavailable'

if err := f.detect(bridgeKernelModuleName); err != nil {
    // not detected: continue without bridge networking capability
    f.logger.Info("bridge kernel module unavailable, bridge networking not advertised")
    return nil
}

When it happens

Trigger: detect('bridge') runs all four probes: /sys/module/bridge missing, 'bridge' not in /proc/modules, not in modules.builtin, not in modules.dep - then findDir/searchFile failures are returned as a combined multierror whose members include this message.

Common situations: Hosts or appliance kernels compiled without the bridge module and without it in modules.dep; heavily stripped VM images; nodes where bridging is unnecessary (the warning is informational).

Related errors

• failed to find %s: %v
• failed to open %s: %v
• failed to scan %s: %v
• fingerprint name cannot be empty
• empty response from AWS metadata

AI-assisted analysis of hashicorp/nomad@482b49bf1a (2026-09-04). Data as JSON: /api/errors/a7fe05b420e45bf8. Report an issue: GitHub.