Ansible shell module returns error when grep results are empty

Question

I am using Ansible\'s shell module to find a particular string and store it in a variable. But if grep did not find anything I am getting an error.

Example:

Answer 1

Like you observed, ansible will stop execution if the grep exit code is not zero. You can ignore it with ignore_errors.

Another trick is to pipe the grep output to cat. So cat exit code will always be zero since its stdin is grep's stdout. It works if there is a match and also when there is no match. Try it.

- name: Get the http_status
  shell: grep "http_status=" /var/httpd.txt | cat
  register: cmdln
  check_mode: no