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