Dnsmasq DHCP

Plugin: go.d.plugin Module: dnsmasq_dhcp

Overview

This collector monitors Dnsmasq DHCP leases databases, depending on your configuration.

By default, it uses:

• /var/lib/misc/dnsmasq.leases to read leases.
• /etc/dnsmasq.conf to detect dhcp-ranges.
• /etc/dnsmasq.d to find additional configurations.

This collector is only supported on the following platforms:

• Linux

This collector only supports collecting metrics from a single instance of this integration.

Default Behavior

Auto-Detection

All configured dhcp-ranges are detected automatically

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Setup

You can configure the dnsmasq_dhcp collector in two ways:

:::important

UI configuration requires paid Netdata Cloud plan.

:::

Prerequisites

No action required.

Configuration

Options

The following options can be defined globally: update_every, autodetection_retry.

via UI

Configure the dnsmasq_dhcp collector from the Netdata web interface:

1. Go to Nodes.
2. Select the node where you want the dnsmasq_dhcp data-collection job to run and click the :gear: (Configure this node). That node will run the data collection.
3. The Collectors → Jobs view opens by default.
4. In the Search box, type dnsmasq_dhcp (or scroll the list) to locate the dnsmasq_dhcp collector.
5. Click the + next to the dnsmasq_dhcp collector to add a new job.
6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
   • Test runs the job with the provided settings and shows whether data can be collected.
   • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

via File

The configuration file name for this integration is go.d/dnsmasq_dhcp.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/dnsmasq_dhcp.conf

Examples

Basic

An example configuration.

jobs:
  - name: dnsmasq_dhcp
    leases_path: /var/lib/misc/dnsmasq.leases
    conf_path: /etc/dnsmasq.conf
    conf_dir: /etc/dnsmasq.d

Pi-hole

Dnsmasq DHCP on Pi-hole.

jobs:
  - name: dnsmasq_dhcp
    leases_path: /etc/pihole/dhcp.leases
    conf_path: /etc/dnsmasq.conf
    conf_dir: /etc/dnsmasq.d

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per Dnsmasq DHCP instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Per dhcp range

These metrics refer to the DHCP range.

Labels:

Metrics:

Alerts

The following alerts are available:

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the dnsmasq_dhcp collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn’t working.

• Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that’s not the case on your system, open netdata.conf and look for the plugins setting under [directories].

  cd /usr/libexec/netdata/plugins.d/
  

• Switch to the netdata user.

  sudo -u netdata -s
  

• Run the go.d.plugin to debug the collector:

  ./go.d.plugin -d -m dnsmasq_dhcp
  

  To debug a specific job:

  ./go.d.plugin -d -m dnsmasq_dhcp -j jobName
  

Getting Logs

If you’re encountering problems with the dnsmasq_dhcp collector, follow these steps to retrieve logs and identify potential issues:

• Run the command specific to your system (systemd, non-systemd, or Docker container).
• Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep dnsmasq_dhcp

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector’s name:

grep dnsmasq_dhcp /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named “netdata” (replace if different), use this command:

docker logs netdata 2>&1 | grep dnsmasq_dhcp