title: How to bind global variable in app service provider in Lumen
body: <p>Lumen microservices, how do we add global variables that can be accessed by the entire platform.</p>
  <p>We can use the app singleton in Laravel as follows:</p>
  <pre><code>App::singleton('lookup', function() {
      return true;
  });
  </code></pre>
  <p>Hence, we can use the variable by using syntax <code>$lookup = app('lookup');</code></p>
  <p>But the same could be true for lumen.</p>
  <p>In the same way, I want to create a global variable in the lumen. This can be used inside of my models.</p>