Where create cookie that holds only user id in Zend MVC project?

Question

Hi,

I am working with Zend MVC project. MY mission: add cookie that will have only user unique id.

Problem:I don't know where create a cookie.

Options to place create a cookie, that I thing about:

1. bootstrap.php init()/run()

2. index.php (not make sense)

3. In Controllers

My project structure:

application/bootstrap.php

public/index.php

---

Please help me, if you can give example it will be great.

Thanks, Yosef