store output of command in variable in ansible

Question

Concerning: Ansible-Playbooks

Is it possible to run a command on the remote machine and store the resulting output into a variable? I am trying to get the kernel version and install the matching headers like this:

---
- hosts: all

  tasks:
    - name: install headers
      become: yes
      become_method: sudo
      apt:
        name: "{{ packages }}"
      vars:
        packages:
        - linux-headers-`uname -r`
        #- a lot of other packages here

Unfortunately uname -r is not executed here.

I am aware of this question: Ansible: Store command's stdout in new variable? But it looks like this is another topic.

score 3 · Accepted Answer · answered Nov 06 '20 at 20:37

By definition:

Ansible facts are data related to your remote systems, including operating systems, IP addresses, attached filesystems, and more.

In this link you can see all ansible facts that you can use. https://docs.ansible.com/ansible/latest/user_guide/playbooks_vars_facts.html

One of those variables is ansible_kernel, this is the version of the kernel of your remote system. By default ansible gets this variables, but if you want to be sure that ansible will get this variables you have to use gather_facts: yes.

---
- hosts: all
  gather_facts: yes
  tasks:
  - name: install
    become: yes
    become_method: sudo
    apt:
      name: "{{ packages }}"
    vars:
      packages:
      - linux-headers-{{ ansible_kernel }}

score 0 · Answer 2 · answered Nov 06 '20 at 20:14

I found a solution but I am not sure if this is really elegant

---
- hosts: all

  tasks:
    - name: Getting Kernel Version
      command: "uname -r"
      register: kernel_version
    - name: install
      become: yes
      become_method: sudo
      apt:
        name: "{{ packages }}"
      vars:
        packages:
        - linux-headers-{{ kernel_version.stdout }}

store output of command in variable in ansible

2 Answers2