custom post and custom fields

I have been trying to run a function from the functions.php file whenever a post is created of my custom post type.

This is the code that i am adding to my function.php file but it doesn’t seem to create the two custom fields s and l when a post is published.

function add_meta_values(){

global $wpdb;
$args = array(  'post_type' => 'sol');
$postslist = get_posts( $args );

foreach ($postslist as $post) :
add_post_meta(get_the_ID(), 's', 0, true);
add_post_meta(get_the_ID(), 'l', 0, true);
 endforeach;  

}
add_action('publish_post', 'add_meta_values');

can someone advise what i am doing wrong here.

thanks in advance
Ilan