无法使用codeigniter在AWS [Ubuntu]上传文件

I have AWS instance with Ubuntu and PHP configured. Every things work perfect. Only file upload not working. Application developed in PHP [codeigniter]

$this->load->library('form_validation');
$config = [
            'upload_path'    =>  "./data/user-avatar",
            'allowed_types'  =>  'gif|jpg|png|jpeg|JPEG',
            'encrypt_name'   =>   TRUE
         ];

        $this->load->library('upload',$config);

 if($this->upload->do_upload())
 {
    $data = $this->upload->data();
    echo $image = $data['file_name'];
 } else {
   echo "I am here in else";
 }

It executive else block directly. Application work fine on local.

1. Checked upload dir permission its 777
2. Check on phpinfo file upload is on

Any help to find of the error will be appreciated.

Thanks Prashant

Did you make sure your max upload size and max post are big enough on php.ini or your main php config file? it could not accept files bigger than X;

Also you could get the $data['error'] to see if you get any code > 0 and find a answer from this; maybe $error = $this->upload->display_errors(); could tell you more

Also check if your directory exists, using is_dir() to make sure you are not pointing to a different relative path (worth the check).