Set variable according to result of another variable?

[John Oliver]

If I:

- name: Copy SSL cert

  copy: src={{ ansible_hostname if ansible_hostname in valid_hosts else ('test') }}.crt

        dest=/etc/pki/tls/certs/

        mode=0644

How can I capture the name of the certificate that was actually copied for action in another task?

[Giovanni Tirloni]

register: cert_copy

- debug: var=cert_copy

http://docs.ansible.com/playbooks_variables.html#registered-variables

Giovanni