Log: fix logging the right IP address when install behind a reverse proxy

src/Log.php

@@ -19,6 +19,12 @@ class Log {
    */
   protected static $file_fd = null;
 
+  /**
+   * PHP error_log() fallback if no filepath configured or fail to open log file
+   * @var bool
+   */
+  protected static $error_log_fallback = true;
+
   /*
    * Log Levels
    * @var array(string,int)
@@ -77,6 +83,9 @@ class Log {
     else
       self :: $filepath = App::get('log.file_path');
 
+    // PHP error_log() fallback
+    self :: $error_log_fallback = App::get('log.error_log_fallback', true, 'bool');
+
     // Set log level
     self :: set_level($level?$level:App::get('log.level'));
 
@@ -124,6 +133,20 @@ class Log {
     set_exception_handler(array('EesyPHP\\Log', 'exception'));
   }
 
+  /**
+   * Get remote IP address
+   * @return string
+   */
+  public static function get_remote_addr(){
+    if (array_key_exists('HTTP_X_FORWARDED_FOR', $_SERVER))
+      return  $_SERVER["HTTP_X_FORWARDED_FOR"];
+    if (array_key_exists('REMOTE_ADDR', $_SERVER))
+      return $_SERVER["REMOTE_ADDR"];
+    if (array_key_exists('HTTP_CLIENT_IP', $_SERVER))
+      return $_SERVER["HTTP_CLIENT_IP"];
+    return '';
+  }
+
   /**
    * Log a message
    * @param string $level The message level (key of self :: $levels)
@@ -138,6 +161,8 @@ class Log {
     if (self :: $levels[$level] < self :: $levels[self :: $level]) return true;
     if(self :: $filepath && is_null(self :: $file_fd)) {
       self :: $file_fd = fopen(self :: $filepath, 'a');
+      if (self :: $file_fd === false)
+        self :: error('Fail to open log file (%s)', self :: $filepath);
     }
 
     // Extra arguments passed, format message using sprintf
@@ -160,7 +185,7 @@ class Log {
       $msg = array(
         date('Y/m/d H:i:s'),
         $_SERVER['REQUEST_URI'],
-        $_SERVER['REMOTE_ADDR'],
+        self :: get_remote_addr(),
       );
       if (Auth::enabled())
         $msg[] = (Auth::user()?Auth::user():'anonymous');
@@ -170,6 +195,8 @@ class Log {
     }
     if (self :: $file_fd)
       fwrite(self :: $file_fd, $msg);
+    elseif (self :: $error_log_fallback)
+      error_log($msg);
 
     if ($level == 'FATAL')
       if (!is_null(self :: $fatal_error_handler))