Set featured image using wp_insert_post - php

Question

// Auto post ( Unique File Date ).
$postData = array(
'post_category' => array( $Category ),
'post_status' => $Post_Status,
'post_type' => $Post_Type
);
$post_id = wp_insert_post( $postData );
$getImageFile = 'http://localhost/Multisite/test2/wp-content/uploads/sites/4/Auto Post/twitter.png';
$attach_id = wp_insert_attachment( $postData, $getImageFile, $post_id );
require_once( ABSPATH . 'wp-admin/includes/image.php' );
$attach_data = wp_generate_attachment_metadata( $attach_id, $getImageFile );
wp_update_attachment_metadata( $attach_id, $attach_data );
set_post_thumbnail( $post_id, $attach_id );
The code above make a post successfully but it is not setting the post featured image. I don't know what I am doing wrong here.

Answer 1

Use different $postData for the attachment:
$wp_filetype = wp_check_filetype( $getImageFile, null );
$attachment_data = array(
'post_mime_type' => $wp_filetype['type'],
'post_title' => sanitize_file_name( $getImageFile ),
'post_content' => '',
'post_status' => 'inherit'
);
$attach_id = wp_insert_attachment( $attachment_data, $getImageFile, $post_id );
Currently you're passing the identical post data to the post and its attachment post.

Answer 2

I use the function wp_upload_bits is new WordPress function for easy for uploading image. On the second line of my code $post is your $post_id id and for upload file directory I create custom folder that is custom-uploads for your better understanding or you can remove that on my 4th line of coding that is './'. 'custom-uploads' . '/'
$upload = wp_upload_bits($_FILES["file"]["name"], null, file_get_contents($_FILES["file"]["tmp_name"]));
$post_id = $posts; //set post id to which you need to set post thumbnail
$filename = $upload['file'];
$uploadfile = $uploaddir['basedir'] . '/'. 'custom-uploads' . '/';
move_uploaded_file($filename, $uploadfile); // (file name , designation)
$wp_filetype = wp_check_filetype($filename, null );
$attachment = array(
'post_mime_type' => $wp_filetype['type'],
'post_title' => sanitize_file_name($filename),
'post_content' => '',
'post_status' => 'inherit'
);
$attach_id = wp_insert_attachment( $attachment, $filename, $posts );
require_once(ABSPATH . 'wp-admin/includes/image.php');
$attach_data = wp_generate_attachment_metadata( $attach_id, $filename );
wp_update_attachment_metadata( $attach_id, $attach_data );
set_post_thumbnail( $post_id, $attach_id ); // set post thumnail (featured image) for the given post