Complete rewrite of the monitoring daemon in PHP

app/Console/Commands/RunMonitoring.php

@@ -0,0 +1,238 @@
+<?php
+
+namespace App\Console\Commands;
+
+use Illuminate\Console\Command;
+use Illuminate\Support\Facades\DB;
+use \Exception;
+use Illuminate\Queue\Console\MonitorCommand;
+
+class RunMonitoring extends Command
+{
+	private $rounds = 50;
+
+    /**
+     * The name and signature of the console command.
+     *
+     * @var string
+     */
+    protected $signature = 'monitolite:monitoring:run {rounds?}';
+
+    /**
+     * The console command description.
+     *
+     * @var string
+     */
+    protected $description = 'Executes all the monitoring tasks';
+
+	/**
+	 * Storing all the results for output
+	 */
+	private $results;
+
+    /**
+     * Create a new command instance.
+     *
+     * @return void
+     */
+    public function __construct()
+    {
+        parent::__construct();
+    }
+
+    /**
+     * Execute the console command.
+     *
+     * @return mixed
+     */
+    public function handle()
+    {
+		$count = 0;
+		$rounds = $this->argument('rounds') ?? $this->rounds;
+
+		// Getting pending tasks
+		$tasks = app('db')->select('
+			SELECT id, host, type, params
+			FROM tasks
+			WHERE ( DATE_SUB(now(), INTERVAL frequency SECOND) > last_execution OR last_execution IS NULL )
+			AND active = 1
+			ORDER BY last_execution ASC
+			LIMIT :limit
+		', [
+			'limit'		=> $rounds
+		]);
+
+		if (is_null($tasks) || count($tasks) == 0) {
+			$this->info('No task to process, going back to sleep');
+			return true;
+		}
+
+		$this->info('I have '.count($tasks).' to process. Better get started ...');
+
+		$this->newLine();
+		$bar = $this->output->createProgressBar(count($tasks));
+		$bar->start();
+
+		foreach ($tasks as $task) {
+			$last_status = $new_status = $output = null;
+			$bar->advance();
+
+			// Getting current task last status
+			$query = DB::table('tasks_history')
+				->select('status')
+				->where('task_id', $task->id)
+				->orderBy('datetime',  'DESC')
+				->first()
+			;
+			if ($query !== false && ! is_null($query)) {
+				$last_status = $query->status;
+			}
+
+			try {
+				switch ($task->type) {
+					case 'ping':
+						$new_status = $this->checkPing($task);
+					break;
+
+					case 'http':
+						$new_status = $this->checkHttp($task);
+					break;
+
+					default:
+						// Nothing to do here
+						continue 2;
+				}
+
+				$this->saveHistory($task, true);
+			}
+			catch(MonitoringException $e) {
+				$this->saveHistory($task, false, $e->getMessage());
+			}
+			catch(Exception $e) {
+				$this->saveHistory($task, false, $e->getMessage());
+			}
+		}
+		$bar->finish();
+		$this->newLine(2);
+
+		if (!empty($this->results)) {
+			$this->table(
+				['Host', 'Result', 'Message'],
+				$this->results
+			);
+		}
+    }
+
+	final private function saveHistory($task, $status, $output = null) {
+		$date = date('Y-m-d H:i:s');
+
+		$this->results[] = [
+			'host'		=> $task->host,
+			'result'	=> $status === true ? 'OK' : 'FAILED',
+			'message'	=> $output
+		];
+
+		$insert = DB::table('tasks_history')
+			->insert([
+				'status'		=> $status === true ? 1 : 0,
+				'datetime'		=> $date,
+				'output'		=> $output ?? '',
+				'task_id'		=> $task->id
+			]
+		);
+
+		if (false !== $insert) {
+			DB::table('tasks')
+				->where('id', $task->id)
+				->update([
+					'last_execution'	=> $date
+				])
+			;
+			return true;
+		}
+	}
+
+	final private function checkPing($task) {
+		if (! function_exists('exec') || ! is_callable('exec')) {
+			throw new MonitoringException('The "exec" command is required');
+		}
+
+		// Different command line for different OS
+		switch (strtolower(php_uname('s'))) {
+			case 'darmin':
+				$cmd = 'ping -n 1 -t 5';
+			break;
+			case 'windows':
+				$cmd = 'ping /n 1 /w 5';
+			break;
+			case 'linux':
+			case 'freebsd':
+			default:
+				$cmd = 'ping -c 1 -W 5';
+			break;
+		}
+
+		// If command failed
+		if (false === $exec = exec($cmd.' '.$task->host, $output, $code)) {
+			throw new MonitoringException('Unable to execute ping command');
+		}
+
+		// If command returned a non-zero code
+		if ($code > 0) {
+			throw new MonitoringException('Ping task failed ('.$exec.')');
+		}
+
+		// Double check
+		$output = implode(' ', $output);
+		// Looking for the 100% package loss output
+		if (preg_match('~([0-9]{1,3})\.[0-9]{0,2}% +(packet)? +loss~', $output, $matches)) {
+			if (! empty($matches[1])) {
+				if (floatval($matches[1]) == 100) {
+					throw new MonitoringException('Packet loss detected ('.($matches[0] ?? 'n/a').')');
+				}
+			}
+		}
+		// Else everything is fine
+		return true;
+	}
+
+	final private function checkHttp($task) {
+		// Preparing cURL
+		$opts = [
+			CURLOPT_HTTPGET					=> true,
+			CURLOPT_FRESH_CONNECT			=> true,
+			CURLOPT_PROTOCOLS				=> CURLPROTO_HTTP | CURLPROTO_HTTPS,
+			CURLOPT_SSL_VERIFYHOST			=> 2,
+			CURLOPT_RETURNTRANSFER			=> true,
+			CURLOPT_FOLLOWLOCATION			=> true,
+			CURLOPT_MAXREDIRS				=> 3,
+			CURLOPT_FAILONERROR				=> true,
+			CURLOPT_CONNECTTIMEOUT			=> 10,
+			CURLOPT_URL						=> trim($task->host)
+		];
+
+		$ch = curl_init();
+		curl_setopt_array($ch, $opts);
+		if ($result = curl_exec($ch)) {
+
+			// We have nothing to check into the page
+			// So for me, this is a big YES
+			if (empty($task->params)) {
+				return true;
+			}
+			// We are looking for a string in the page
+			else {
+				if (strpos($result, $task->params) !== false) {
+					return true;
+				}
+				else {
+					throw new MonitoringException('Cannot find the required string into the page');
+				}
+			}
+		}
+		throw new MonitoringException(curl_error($ch), curl_errno($ch));
+	}
+}
+
+class MonitoringException extends Exception {}
+

app/Console/Kernel.php

@@ -5,6 +5,8 @@ namespace App\Console;
 use Illuminate\Console\Scheduling\Schedule;
 use Laravel\Lumen\Console\Kernel as ConsoleKernel;
 use App\Console\Commands\SyncCustomers;
+use App\Console\Commands\CleanHistory;
+use App\Console\Commands\RunMonitoring;
 
 class Kernel extends ConsoleKernel
 {
@@ -14,7 +16,9 @@ class Kernel extends ConsoleKernel
      * @var array
      */
     protected $commands = [
-        SyncCustomers::class
+        SyncCustomers::class,
+        CleanHistory::class,
+        RunMonitoring::class
     ];
 
     /**
@@ -30,7 +34,12 @@ class Kernel extends ConsoleKernel
          * You may safely remove this scheduled task
          */
         if (env('CMS_ENABLE_SYNC') == true) {
-            $schedule->command('customers:sync')->hourly();
+            $schedule->command('monitolite:customers:sync')->hourly();
-        }
+        }
+
+        /**
+         * This is the main monitoring task
+         */
+        $schedule->command('monitolite:monitoring:run')->everyMinute();
     }
 }