Post save callback to cache JSON api

wordpress-api-hook.php

  function post_saved_json_callback($post_id)
  {
    $url = "http://localhost/api/get_posts/?post_type=page,artist,release,episode,post&posts_per_page=10000";
    $content = file_get_contents($url);
    $output = TEMPLATEPATH . '/brunch-app/public/data/posts.json';

    file_put_contents($output, $content);

  }

  // save post updates the json file
  add_action( 'save_post', 'post_saved_json_callback' );