Search page for custom post type

You can simply include a custom search function into your search by using pre_get_posts

You can do something like this

function search_filter($query) {
  if ( !is_admin() && $query->is_main_query() ) {
    if ($query->is_search) {
      $query->set('post_type', 'your-custom-post-type' );
    }
  }
}

add_action('pre_get_posts','search_filter');