Variable Precedence (version 1.2)

1) Variables defined in the play under vars_files

normalvars_files:
  - "/path/to/var/file"
normal

2) Variables defined in  <role>/vars/main.yml 

3) Variables passed in on the command line

normalansible-playbook ... -e "test_var=foo"
normal

4) Variables defined in the play under vars

normalvars:
  test_var: foo
normal

5) Variables defined in  group_vars/ 

edX Variable conventions

Role variables

Default variables for roles should all be defined in  <role>/vars/main.yml  file associated with the role. This is currently not the lowest priority definition, in fact it's the number (2) in precedence. Ansible 1.3 will be introducing new role default vars which will allow us to