Agent builder

The Agents module, introduced in version 1.6.0, builds monitoring agent packages for Windows and Linux on the Energy Monitor server. Each package carries its own configuration, the list of hosts allowed to query the agent and optional custom check scripts, so hosts of the same class can be deployed from one package.

The module is available from the Agents entry on the main bar, with separate pages for Windows and Linux.

Note: After an upgrade from 1.5.x the pages return 403 until an administrator enables the agents_access permission under Manage -> Configuration -> Group Rights. A fresh 1.6.0 installation has the permission enabled.

Windows agents

Windows agents

The Windows agent is NSClient++. The page offers:

  • Select Agent Version: the NSClient++ version to package (0.9.4 in 1.6.0).

  • Existing Windows Agents: the packages built so far, with the agent name, the allowed hosts, the version, and the actions Download, Remove and Config.

  • The Agent form: agent_name, allowed_hosts and custom ini, the content of nsclient.ini with the enabled modules, ports, authentication and allowed hosts.

  • Upload script file: custom check scripts bundled into the package.

Fill in the form, upload scripts if needed and save. The package appears in the table and Download fetches an MSI installer (NSClient++_windows_agent.msi, NSClient++ 0.9.4 x64) built with the nsclient.ini from the form. The agent listens on the NRPE port 5666. The older CheckNT method on port 12489 is still supported but being retired.

Linux agents

Linux agents

The Linux agent is NRPE. The page offers:

  • Select Agent Version: 4.1.3 or 4.0.3.

  • Select distribution: Ubuntu 24, 22, 20; Debian 13, 12; Red Hat Enterprise Linux 10, 9, 8; AlmaLinux 10, 9, 8; Rocky Linux 10, 9, 8; Oracle Linux 10, 9, 8.

  • Existing Linux Agents: the packages built so far, with an extra Distro column.

  • The Agent form: agent_name, allowed_hosts and custom cfg, the NRPE configuration with commands, ports, authentication and allowed hosts.

  • Upload script file: custom check scripts bundled into the package.

A package is built for the chosen distribution and downloaded from the table: a .deb for Debian and Ubuntu (nrpe-plugins_3.0.0-5_amd64_<name>.deb) and an .rpm for the Red Hat family (energy-nrpe-plugins-3.0.0-5.el8.x86_64_<name>.rpm, el9 for the 9 and 10 releases). The package installs the NRPE agent with the Energy Monitor plugins in /opt/plugins, the configuration from the form in /etc/nrpe.d/custom.cfg and a reference /etc/nagios/nrpe.cfg.new. Install it with the distribution’s package manager; the agent listens on port 5666.

Allowed hosts

allowed_hosts lists the addresses that may query the agent: the Energy Monitor server and any poller that will run checks against the host. A host that queries the agent from an address outside the list is refused.

Changes in 1.6.0

Group permissions in the builder, faster download of uploaded scripts and Debian 12 compatibility.

Technical notes

  • The build environment lives in /opt/agents; the nachos service handles agents and scans.

  • The pages are Nacoma pages (windows_agents.php, linux_agents.php) rendered inside the main interface in an iframe.

  • Access is controlled by the agents_access permission in /etc/energy-monitor/auth_groups.yml.