add a ansible_debug role that just dumps vars into json

playbooks/roles/ansible_debug/tasks/main.yml

+---
+- name: Dump all vars
+  action: template src=dumpall.j2 dest=/tmp/ansible.all
+  tags:
+  - dumpall
+  - debug
\ No newline at end of file

playbooks/roles/ansible_debug/templates/dumpall.j2

+Module Variables ("vars"):
+--------------------------------
+{{ vars | to_nice_json }}
+
+Environment Variables ("environment"):
+--------------------------------
+{{ environment | to_nice_json }}
+
+GROUP NAMES Variables ("group_names"):
+--------------------------------
+{{ group_names | to_nice_json }}
+
+GROUPS Variables ("groups"):
+--------------------------------
+{{ groups | to_nice_json }}
+
+HOST Variables ("hostvars"):
+--------------------------------
+{{ hostvars | to_nice_json }}
+
+{% if lms_env_config %}
+LMS env variables:
+---------------
+{{ lms_env_config | to_nice_json }}
+{% endif %}
+
+{% if lms_auth_config %}
+LMS auth variables:
+---------------
+{{ lms_auth_config | to_nice_json }}
+{% endif %}
+
+{% if lms_preview_env_config %}
+Preview env variables:
+---------------
+{{ lms_preview_env_config | to_nice_json }}
+{% endif %}
+
+{% if lms_preview_auth_config %}
+Preview auth variables:
+---------------
+{{ lms_preview_auth_config | to_nice_json }}
+{% endif %}
+
+{% if cms_env_config %}
+CMS env variables:
+---------------
+{{ cms_env_config | to_nice_json }}
+{% endif %}
+
+{% if cms_auth_config %}
+CMS auth variables:
+---------------
+{{ cms_auth_config | to_nice_json }}
+{% endif %}