module - Ansible extract shell output using awk

Question

---
- name: Data Collection
  hosts: all
  tasks:
    - name: List all users
      shell: "cat /etc/passwd | awk -F: '{print $1}'"
      register: users
    - lineinfile:
        dest: /tmp/users.csv
        create: yes
        line: "The {{ inventory_hostname}}, {{ users.stdout }}"
      delegate_to: localhost

Doesn't give the intended output as I'm getting syntax error for using awk / grep in shell module. Kindly refer the intended output.

172.17.254.201, root
172.17.254.201, bin
172.17.254.201, nobody
172.17.254.201, test1
172.17.254.201, test2
172.17.254.202, root
172.17.254.202, bin
172.17.254.202, nobody
172.17.254.202, test1
172.17.254.202, test2
..

Answer 1

Are you certain the error is related to the shell task? I was able to run it without errors.

One issue with the provided example is that lineinfile is only used once (i.e. only a single line will be updated). We can solve this issue by utilizing Ansible loop.

---
- name: Data Collection
  hosts: all
  tasks:
    - name: List all users
      shell: "cat /etc/passwd | awk -F: '{print $1}'"
      register: users
    - lineinfile:
        dest: /tmp/users.csv
        create: yes
        line: "{{ inventory_hostname}}, {{ item }}"
      loop: "{{ users.stdout_lines }}"
      delegate_to: localhost

If you're using DNS records in the inventory file but want IP addresses in the .csv file, then you'll want to replace inventory_hostname with a host_vars lookup (likely) for hostvars[inventory_hostname]['ansible_default_ipv4']['address'].

If not, the above example should suffice.