add cpu usage check

readme.md

@@ -45,6 +45,7 @@ The package comes with following checks out of the box. Checks can be divided in
 
  - :white_check_mark:  Required PHP extensions are installed
  - :white_check_mark:  Disk Space Enough
+ - :white_check_mark:  Average CPU Usage
  - :white_check_mark:  FTP Connection Works
  - :white_check_mark:  SFTP Connection Works
  - :white_check_mark:  SSL Certificate Valid

src/Checks/Server/AvgCpuUsage.php

@@ -0,0 +1,48 @@
+<?php
+/**
+ * Created by PhpStorm.
+ * User: Sarfraz
+ * Date: 7/10/2019
+ * Time: 2:39 PM
+ */
+
+namespace Sarfraznawaz2005\ServerMonitor\Checks\Server;
+
+use Sarfraznawaz2005\ServerMonitor\Checks\Check;
+
+class AvgCpuUsage implements Check
+{
+    private $percent;
+
+    /**
+     * Perform the actual verification of this check.
+     *
+     * @param array $config
+     * @return bool
+     */
+    public function check(array $config): bool
+    {
+        $this->percent = round($this->getCPUUsagePercentage(), 2);
+
+        $failPercentage = $config ['fail_percentage'];
+
+        return !($this->percent >= $failPercentage);
+    }
+
+    protected function getCPUUsagePercentage()
+    {
+        $cpu = shell_exec("grep 'cpu ' /proc/stat | awk '{usage=($2+$4)*100/($2+$4+$5)} END {print usage}'");
+
+        return (float)$cpu;
+    }
+
+    /**
+     * The error message to display in case the check does not pass.
+     *
+     * @return string
+     */
+    public function message(): string
+    {
+        return 'Average CPU usage at: ' . $this->percent . '%';
+    }
+}

src/Config/config.php

@@ -56,6 +56,9 @@
             \Sarfraznawaz2005\ServerMonitor\Checks\Server\DiskSpaceEnough::class => [
                 'fail_percentage' => 90
             ],
+            \Sarfraznawaz2005\ServerMonitor\Checks\Server\AvgCpuUsage::class => [
+                'fail_percentage' => 90
+            ],
 
             /*
             \Sarfraznawaz2005\ServerMonitor\Checks\Server\CheckPhpIniValues::class => [

src/ServerMonitor.php

@@ -105,7 +105,7 @@ public function runChecks(): array
                         'name' => getCheckerName($check, $config),
                         'status' => $status,
                         'error' => $error,
-                        'time' => sprintf("%dms", $eTime),
+                        'time' => sprintf('%dms', $eTime),
                     ];
                 }
             }
@@ -159,7 +159,7 @@ public function runCheck($checkClass): array
                             'name' => getCheckerName($check, $config),
                             'status' => $status,
                             'error' => $error,
-                            'time' => sprintf("%dms", $eTime),
+                            'time' => sprintf('%dms', $eTime),
                         ];
                     }
                 }