How to get and parse the output from target hosts

[Jörg Kastning]

Hello,

I would like to write a playbook to install Red Hat Security Advisory on my hosts. The idea is to put the published information about the advisories with their Numbers (e.g. RHSA-2016:1234) in a variable and run the following playbook on all hosts:

---
- hosts: all

  tasks:
    - name: Group by OS
      group_by: key=os_{{ ansible_distribution }}
      changed_when: False

- hosts: os_RedHat
  vars:
    RHSA: "RHSA-2016:1633, RHSA-2016:1626"
  tasks:
    - name: Install Red Hat Security Advisory
      command: yum update-minimal --advisory {{ RHSA }}
      register: yumoutput

    - name: Reboot if packages were updated
      command: reboot NOW
      when: yumoutput = ???

As you could see I would like to reboot a host only in case packages were updated. As far as I know the last line in the yum output on the host should be "Complete!". But I have trouble to get only the last line from the output and use it in the conditional when clause.

Could someone help me here, please?

Because english is not my first language I may have difficulties to make my point. Please bare with me and ask for more details or points I have to make more clear.

Kind regards,
Joerg

[Alexander H. Laughlin]

I believe something like:

- name: Reboot if packages were updated
  command:

reboot NOW
  when: "'Complete!' in yumoutput"

would do the trick.

http://docs.ansible.com/ansible/playbooks_conditionals.html#applying-when-to-roles-and-includes

http://stackoverflow.com/questions/30533372/run-an-ansible-task-only-when-the-hostname-contains-a-string

That is assuming that you don't have the string 'Complete!' turning up anywhere else in the output.

[Jörg Kastning]

Hi Alexander,

you put me in the right direction. I'd like to give a short example for my solution:

---
- name: show return value of command yum
  hosts: e-stage
  tasks:
    - name: command
      command: yum update-minimal --advisory RHSA-2016:1234
      register: yumlog

    - command: reboot NOW
      when: '"Completed!" in "{{ yumlog.stdout_lines[-1] }}"'

With "{{ yumlog.stdout_lines[-1] }}" I got the last item from the list and do not have to think about the case when it occures somewhere else in the output.

Greetz
Joerg