loadmeter.php

<?php
/**
 * ____________________________________________________________________________
 * 
 *  _____ _____ __                   _____         _ _           
 * |     |     |  |      ___ ___ ___|     |___ ___|_| |_ ___ ___ 
 * |-   -| | | |  |__   | .'| . | . | | | | . |   | |  _| . |  _|
 * |_____|_|_|_|_____|  |__,|  _|  _|_|_|_|___|_|_|_|_| |___|_|  
 *                          |_| |_|                              
 *                           _ _         _                                            
 *                       ___| |_|___ ___| |_                                          
 *                      |  _| | | -_|   |  _|                                         
 *                      |___|_|_|___|_|_|_|   
 *                                                               
 * ____________________________________________________________________________
 * 
 * SHOW LOAD AS LINE
 * 
 * A plugin always is loaded in clases/appmonitor-checks.class.php
 * Have look there for the used protected classes
 * ____________________________________________________________________________
 * 
 * PARAMS:
 *   warning {float}  limit to switch to warning
 *   error   {float}  limit to switch to error
 * 
 * USAGE:
 * 
 * $oMonitor->addCheck(
 *     [
 *         "name" => "plugin Load",
 *         "description" => "check current load",
 *         "check" => [
 *             "function" => "Loadmeter",
 *             "params" => [
 *                "warning" => 1.0,
 *                "error" => 3,
 *             ],
 *         ],
 *         "worstresult" => RESULT_OK
 *     ]
 * );
 * ____________________________________________________________________________
 * 
 * 2019-06-06  <axel.hahn@iml.unibe.ch>
 * 2024-07-23  <axel.hahn@unibe.ch>      php 8 only: use typed variables
 * 2024-07-25  <axel.hahn@unibe.ch>      float return with 2 digits behind comma
 * 2025-03-19  <axel.hahn@unibe.ch>      add validation rules and parameter description
 */
class checkLoadmeter extends appmonitorcheck
{
    /**
     * Self documentation and validation rules
     * @var array
     */
    protected array $_aDoc = [
        'name' => 'Plugin Loadmeter',
        'description' => 'Get system load and render it as a tile.',
        'parameters' => [
            'warning' => [
                'type' => 'float',
                'required' => false,
                'description' => 'Warning level',

                // doc
                'default' => null,
                'example' => '1.5',
            ],
            'error' => [
                'type' => 'float',
                'required' => false,
                'description' => 'Critical level when to raise an error',
                'default' => null,
                'example' => '2.5',
            ],
        ],
    ];

    /**
     * Get default group of this check
     * @return string
     */
    public function getGroup(): string
    {
        return 'monitor';
    }

    /**
     * Detect load of a machine and return a float value
     * windows part was taken from https://stackoverflow.com/questions/5588616/how-do-you-calculate-server-load-in-php
     * @return float
     */
    protected function _getLoad(): float
    {
        if (function_exists('sys_getloadavg')) {
            $load = sys_getloadavg();
            return $load[0];
        } else {
            // Only MS Windows has not implemented sys_getloadavg
            // try something else
            if (class_exists('COM')) {
                $wmi = new COM('WinMgmts:\\\\.');
                $cpus = $wmi->InstancesOf('Win32_Processor');
                $load = 0;
                if (version_compare('4.50.0', PHP_VERSION) == 1) {
                    while ($cpu = $cpus->Next()) {
                        $load += $cpu->LoadPercentage;
                    }
                } else {
                    foreach ($cpus as $cpu) {
                        $load += $cpu->LoadPercentage;
                    }
                }
                return $load;
            }
            return false;
        }
    }

    /**
     * Run the check and get load
     * @param array   $aParams  optional array with keys warning,error
     * @return array
     */
    public function run(array $aParams): array
    {

        // --- (1) verify if array key(s) exist:
        // $this->_checkArrayKeys($aParams, "...");

        // --- (2) do something magic
        // $fLoad=rand(0, 1.3);
        // $fLoad=$this->_getServerLoad();
        $fLoad = $this->_getLoad();

        // set result code
        if ($fLoad === false) {
            $iResult = RESULT_UNKNOWN;
        } else {
            $iResult = RESULT_OK;
            if (isset($aParams['warning']) && $aParams['warning'] && $fLoad > $aParams['warning']) {
                $iResult = RESULT_WARNING;
            }
            if (isset($aParams['error']) && $aParams['error'] && $fLoad > $aParams['error']) {
                $iResult = RESULT_ERROR;
            }
        }


        // --- (3) response
        // see method appmonitorcheck->_setReturn()
        // 
        // {integer} you should use a RESULT_XYZ constant:
        //              RESULT_OK|RESULT_UNKNOWN|RESULT_WARNING|RESULT_ERROR
        // {string}  output text 
        // {array}   optional: counter data
        //              type   => {string} "counter"
        //              count  => {float}  value
        //              visual => {string} one of bar|line|simple (+params)
        //           
        return [
            $iResult,
            ($fLoad === false ? 'load value is not available' : 'current load is: ' . round($fLoad, 2)),
            ($fLoad === false
                ? []
                : [
                    'type' => 'counter',
                    'count' => round($fLoad, 2),
                    'visual' => 'line',
                ]
            )
        ]
        ;
    }
}