JSON API Wordpress not showing featured image when uploaded via App

Question

I am facing some unknown issues with wordpress featured image. When I update a featured image from the website; it gets displayed in the app via json.

http://indiafastener.com/api/?json=get_post&post_type=listing-item&id=1377

however when I upload an image via json into the wordpress db; the output is NULL in the image field.

http://indiafastener.com/api/?json=get_post&post_type=listing-item&id=1380

when I see the db; it has the image path and the path does not lead to 404.

Image Path: http://www.indiafastener.com/webservices/listing/uploads/2017-04-01_12-01-40IMG-20150715-WA0004.jpg

Could it be because the image is not there in the wp-content/uploads/2016/02/ folder?

Code to upload the image

require_once('../../wp-config.php');
require_once('../../wp-admin/includes/image.php');
$dirname = "../../wp-content/uploads/2017/01/";
$filename = $_FILES["file"]["name"];

$attachment = array(
    'post_mime_type' => 'image/jpeg',
    'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
    'post_content' => '',
    'post_status' => 'inherit',
    'guid' => $dirname.basename($filename)
//'wp-content/uploads/2017/01/' . basename($filename)
);
$your_post_id  = 1392;
$attach_id = wp_insert_attachment( $attachment, $filename,'$your_post_id' );
$attach_data = wp_generate_attachment_metadata( $attach_id, $filename );
wp_update_attachment_metadata( $attach_id, $attach_data );
//$id=1385;
update_post_meta($id, '_thumbnail_id', $attach_id);
echo "success";

Any help on this will be highly appreciated.

Screenshots

DB post_type attachment of image uploaded via app

DB Post linked to the image Id

Missing Image Preview:

Answer 1

I am not sure about your code but my below piece of code is working perfectly for assign image as feature image for post. please go through it. attachment id should be assign to particulate post, check your post meta '_thumbnail_id' for post as well.

require_once(ABSPATH . 'wp-admin/includes/image.php');

$filename = 'your file name';

$attachment = array(
    'post_mime_type' => 'your mime type',
    'post_title' => preg_replace('/\.[^.]+$/', '', basename($filename)),
    'post_content' => '',
    'post_status' => 'inherit',
    'guid' => $wp_upload_dir['url'] . '/' . basename($filename)
);
$attach_id = wp_insert_attachment( $attachment, $filename,'your_post_id' );
$attach_data = wp_generate_attachment_metadata( $attach_id, $filename );
wp_update_attachment_metadata( $attach_id, $attach_data );
update_post_meta($id, '_thumbnail_id', $attach_id);