---
- name: check whether {{app}}.war.bak exists
  shell: cd {{root_dir}}/webapps/ && [ -f {{app}}.war.bak ]
  ignore_errors: true
  register: result
- name: revert {{app}}.war.bak
  when: result is succeeded
  shell: cd {{root_dir}}/webapps/ && rm -rf {{app}}.war {{app}} && mv {{app}}.war.bak {{app}}.war