CheckMK agent

This flake provides a package for using the packaged checkmk agent via Nix. It supports most common checks and also has optional supports for advanced checks, like MegaRaid or OVS.

The provided outputs are:

• packages.x86_64-linux.checkmk-agent: nix package for checkmk agent, at the time of writing for version 2.3.0p26
• (wip) nixosModules.default: NixOS module for using checkmk-agent as service

The only supported platform is x86_64-linux. It should also work on other platforms however we currently don't have any testing setup for this.

Use with mon.hlrn.de

A prerequisite is a priviledged user account on mon.zibint.hlrn.de.

1. Include the module and enable in your system config:

{
  inputs = {
    [... your inputs]
    cmk_agent = {
      url = "git+ssh://git@git.zib.de/hpc-s/checkmk-agent.nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs = { ..., cmk_agent, ... }: {
      nixosConfigurations.your-system = nixpkgs.lib.nixosSystem {
          modules = [
            cmk_agent.nixosModules.default
            ({ ... }: {
              services.cmk_agent.enable = true;
            })
          ];
      };
  }
}

If you also want to use cmk-agent-ctl, add:

{ config, ... }: {
  environment.systemPackages = [ config.services.cmk_agent.package ];
}

You should also open the TCP port 6556, if you want to operate the agent in pull mode (this is what you usually want):

{ config, ... }: {
  networking.firewall.interfaces.<interface>.allowedTCPPorts = [ 6556 ];
}

2. Follow the steps in the wiki after create host. For example (for adm): cmk-agent-ctl register --server mon.adm.hlrn.de --site HPC --user agent_registration --hostname $(hostname -f)

Optional checks

The agent itself is a portable bash script. It checks the $PATH at runtime for uncommon dependencies, like postfix, and, if found, evaluates them. If a binary is not found it will skip the check.

This allows the nix derivation to offer opt-in checks for some services to reduce the derivation size for most installations. Most common checks, like the systemd-based checks, are always included to make integration easier.

The supported options are:

• lnxSupport (default: true): state of network interfaces of Linux hosts
• multipathSupport (default: false): state of multipathd
• encryptionSupport (default: true): encryption of agent messages
• zfsSupport (default: false): monitoring of zpools and ZFS datasets
• (untested)lvmSupport (default: false): monitoring of lvm
• (untested)ovsSupport (default: false): monitor openvswitch
• (untested)chronySupport (default: false): monitor chrony
• ipmiSupport (default: false): monitor IPMI with freeipmi and ipmitool
• (untested)dmraidSupport (default: false): monitor device-mapper RAID
• megaraidSupport (default: false): monitor MegaRaid with storcli and megacli
• postfixSupport (default: true): monitor postfix mailqueues
• (untested)varnishSupport (default: false): monitor varnish
• (untested) ntpdSupport (default: false): monitor ntpd

(untested): checks that have yet to be tested on a machine.