Script to upload images of a local folder to a wordpress server, create a Custom Post Type item, and an Attachment, to add as featured image of that CPT. We do that to help as a bulk operation to add lot of testimonials images for a client.

add_testimonials.php

<?php 

class addDepoimentosWithPhotosInFolder {

    static $fullpath_dir;
    static $files = [];
    static $depoimento_section;
    static $current_post_id;
    static $current_attach_id;
    static $current_filename;
    static $wp_upload_dir;
    static $total_files;

    static function init($section) {
        echo "\n preparing to add depoimentos to " . $section;
        self::$wp_upload_dir = wp_upload_dir();
        self::$fullpath_dir = getcwd();
        self::$depoimento_section = $section;
        self::readFilesInServer();
        self::addEachFileToPost();

        echo "\nposts added with success!";
    }

    static function readFilesInServer() {
        echo "\n reading all images files...";
        foreach (glob("*.{jpg,png,gif,JPG,PNG,GIF,bmp,webm,WEBM,BMP}", GLOB_BRACE) as $file) {
            self::$files[] = $file;
        }
        self::$total_files = count(self::$files);
        echo "\n done reading >>>>>>>>  " . self::$total_files . " <<<<<<<<<<<< !\n\n";
    }

    static function addEachFileToPost() {
        $couting = 1; 
        foreach (self::$files as $file) {
            echo "\n\n ================================ " . $couting . " of " . self::$total_files;

            self::$current_filename = static::$fullpath_dir . '/' . $file;
            self::createPost();
            self::setPostThumbnailAttachment();

            $couting++;
            
        }
    }

    static function createPost() {
        echo "\n creating post...";
        $depoimento = array(
            'post_title'   => preg_replace( '/\.[^.]+$/', '', basename( self::$current_filename ) ),
            'post_status'  => 'publish',
            'post_type'  => 'depoimentos'
        );

        if (self::$depoimento_section)
            $depoimento['meta_input'] = array(
                'mblog-depoimentos-section' => self::$depoimento_section
            );

        self::$current_post_id = wp_insert_post( $depoimento );
        echo "\n post inserted: ID: " . self::$current_post_id;
    }

    static function setPostThumbnailAttachment() {
        echo "\n preparing to set post Thumbnail Attachment...";
        
        self::createAttachment();

        // Make sure that this file is included, as wp_generate_attachment_metadata() depends on it.
        require_once( ABSPATH . 'wp-admin/includes/image.php' );

        self::generateMetadataForAttachmentAndUpdateDatabase();
        
        echo "\n add thumbnail to post...";

        set_post_thumbnail( self::$current_post_id, self::$current_attach_id );

    }

    static function createAttachment() {
        $file = self::moveFileToUploadsWpDirectory();

        // Check the type of file. We'll use this as the 'post_mime_type'.
        $filetype = wp_check_filetype( basename( self::$current_filename ), null );
 
        // Prepare an array of post data for the attachment.
        $attachment = array(
            // 'guid'           => self::$wp_upload_dir['url'] . '/' . basename( self::$current_filename ), 
            'post_mime_type' => $filetype['type'],
            'post_title'     => preg_replace( '/\.[^.]+$/', '', basename( self::$current_filename ) ) . '_media',
            'post_content'   => '',
            'post_status'    => 'inherit'
        );
        
        // Insert the attachment.
        self::$current_attach_id = wp_insert_attachment( $attachment, $file, self::$current_post_id );
        echo "\n attachment inserted: ID: " . self::$current_attach_id;
    }

    static function generateMetadataForAttachmentAndUpdateDatabase() {
        echo "\n generating metadata and updating database...";

        $attach_data = wp_generate_attachment_metadata( self::$current_attach_id, self::$current_filename );
        wp_update_attachment_metadata( self::$current_attach_id, $attach_data );
    }

    static function moveFileToUploadsWpDirectory() {
        $image_data = file_get_contents(self::$current_filename);
        $filename = basename(self::$current_filename);
        if(wp_mkdir_p(self::$wp_upload_dir['path']))     
            $file = self::$wp_upload_dir['path'] . '/' . $filename;
        else                                    
            $file = self::$wp_upload_dir['basedir'] . '/' . $filename;

        file_put_contents($file, $image_data);
        return $file;
    }
}

run.sh

printf 'zipping files \n\n'
zip -r testimonials.zip testimonials/

printf 'upload files to server \n\n'
scp testimonials.zip myserver:/home/client/www/wp-content/uploads/
scp add_testimonials.php myserver:/home/client/www/wp-content/uploads/
rm -rf testimonials.zip

printf 'login to server \n\n'
ssh myserver "bash -s" < ./server.sh

printf 'all done.'

server.sh

printf 'going to uploads directory \n\n' 
pwd && cd /home/client/www/wp-content/uploads/ && pwd

printf 'removing older folder \n\n'
rm -rf testimonials/

printf 'unzipping files and removing zip \n\n'
unzip testimonials.zip && rm -rf testimonials.zip

printf 'moving script php to folder \n\n'
mv add_testimonials.php testimonials/

printf 'changing perms \n\n'
cd testimonials && chown -R client:client ./

printf 'adding depoimentos to site... \n\n'
wp eval "include('./add_testimonials.php');addDepoimentosWithPhotosInFolder::init('client');" --allow-root

printf '\n service completed.. exiting... \n\n'
exit