Insert wordpress post using wp_insert_post and attach the featured image

I tried to insert a post using the wp_insert_post function in the functions.php file, the post successfully inserted, but not for the attachment for featured image.

Anyone can help on this, what's wrong with my code below:

$post_if = $wpdb->get_var("SELECT count(post_title) FROM $wpdb->posts WHERE post_title like '$title'");
if($post_if < 1){
    //coded
    $new_post = array(
        'post_title' => $title,
        'post_content' => $contents,
        'post_status' => 'publish',
        'post_author' => 1,
        'post_type' => 'post'
);

$post_id = wp_insert_post($new_post); 
$image = "https://fake.org/image.jpg";


$media = media_sideload_image($image, $post_id); //$post_id from wp_insert_post


// therefore we must find it so we can set it as featured ID
if(!empty($media) && !is_wp_error($media)){
    $args = array(
        'post_type' => 'attachment',
        'posts_per_page' => -1,
        'post_status' => 'any',
        'post_parent' => $post_id
    );

    // reference new image to set as featured
    $attachments = get_posts($args);

    if(isset($attachments) && is_array($attachments)){
        foreach($attachments as $attachment){
            // grab source of full size images (so no 300x150 nonsense in path)
            $image = wp_get_attachment_image_src($attachment->ID, 'full');
            // determine if in the $media image we created, the string of the URL exists
            if(strpos($media, $image[0]) !== false){
                // if so, we found our image. set it as thumbnail
                set_post_thumbnail($post_id, $attachment->ID);
                // only want one image
                break;
            }
        }
    }
}

I tried so many tutorials, I found over the web, nothing to work.

Please any one has experienced with this can share a solution.

Big Thanks

You would need to set the "featured image" first and then try to query it. You tried to do the opposite. Also set the parent id in the wp_insert_attachment function not in the arguments.

So try this code:

$new_post = array(
    'post_title'   => $title,
    'post_content' => $contents,
    'post_status'  => 'publish',
    'post_author'  => 1,
    'post_type'    => 'post'
);

$post_id = wp_insert_post($new_post);

$image = "https://fake.org/image.jpg";

$attachment_file_type = wp_check_filetype(basename($image), null);

$wp_upload_dir = wp_upload_dir();

$attachment_args = array(
    'guid'           => $wp_upload_dir['url'] . '/' . basename($image),
    'post_title'     => preg_replace('/\.[^.]+$/', '', basename($image)),
    'post_mime_type' => $attachment_file_type['type']
);

$attachment_id = wp_insert_attachment($attachment_args, $image, $post_id);

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

$attachment_meta_data = wp_generate_attachment_metadata($attachment_id, $image);

wp_update_attachment_metadata($attachment_id, $attachment_meta_data);

set_post_thumbnail($post_id, $attachment_id);

Here's the documentation page for

wp_insert_attachment

Reference:

https://developer.wordpress.org/reference/functions/wp_insert_attachment/#user-contributed-notes