How to email error logs to developer on Yii2 apps

Logging is a very important feature of the application. It let's you know what is happening in every moment. By default, Yii2 basic and advanced application have just a \yii\log\FileTarget target configured.

To receive emails with messages from the app, setup the log component to email (or Telegram, or slack) transport instead (or besides) of file transport:

'components' => [
    // ...
    'log' => [
         'targets' => [
             [
                 'class' => 'yii\log\EmailTarget',
                 'mailer' => 'mailer',
                 'levels' => ['error', 'warning'],
                 'message' => [
                     'from' => ['log@example.com'],
                     'to' => ['developer1@example.com', 'developer2@example.com'],
                     'subject' => 'Log message',
                 ],
             ],
         ],
    ],
    // ...
],

The \yii\log\EmailTarget component is another way to log messages, in this case emailing them via the mailer component of the application as specified on the mailer attribute of EmailTarget configuration. Note that you can also specify messages properties and which levels of messages should be the sent trough this target.

If you want to receive messages via other platforms besides email, there are other components that represents log targets:

Or you can implement your own by subclassing \yii\log\Target