get_ansible_roles_vars.yml

---
# Assuming there is a roles pattern in use, 
# including subdirectory roles with 
# roles/vars/main.yml (for storing variables in roles/vars/main.yml)
# and roles/example/main.yml
# 
# top-level playbook example.yml looks like:
# ---
#
#- hosts: myhost
#  roles:
#    - example
#
# the underlying tasks at roles/example/main.yml looks like:
#
- name: echo_vars
  command: echo "{{vars[item]}}"
  with_items: "{{vars}}"
  register: output_echo_vars

- debug: var=output_echo_vars.stdout