Add a User to a Second Group on Linux - Ansible module user

How to automate the adding of a user "example" to a system or user-defined groups list on a target the Linux with few lines of Ansible playbook code.

December 14, 2021

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#ansible #user #module #linux #user-management #rhel #centos #fedora #ubuntu #debian #suse #useradd

How to add a user to a second group on Linux with Ansible?

I’m going to show you a live demo with some simple Ansible code. I’m Luca Berton and welcome to today’s episode of Ansible Pilot.

Ansible adds a user to second a group

ansible.builtin.user
Manage user accounts

Today we’re talking about the Ansible module user. The full name is ansible.builtin.user, which means that is part of the collection of modules “builtin” with ansible and shipped with it. It’s a module pretty stable and out for years, it manages user accounts. It supports a huge variety of Linux distributions, SunOS and macOS and FreeBSD. For Windows, use the ansible.windows.win_user module instead.

Parameters

name string - username
group - user’s primary group (only one)
groups list / elements=string - list of groups user will be added to
append boolean - no/yes - If yes, add the user to the groups specified in groups. If no, replace.

This module has many parameters, let me highlight the use for our use-case. The only required is “name”, which is the username. The primary group is specified in the “group” parameter, every user needs to be part of only one group. The “groups” parameter specifies the list of additional groups that the user will be added to. This type of group sometimes is called also “secondary”, “additional” or “supplementary”. The parameter “append” is very important. With the “yes” option, the user is going to be added to the specified groups. With the “no” option, all group members are going to be overwritten with the specified groups. So to recap is you specify the “no” option you are going to lose all the previous group associations, please be careful!

demo

Add a user to second a group with Ansible Playbook.

code

user_group_addsecondary.yml

---
- name: user module demo
  hosts: all
  become: true
  vars:
    myuser: "example"
    mygroups:
      - adm
      - sys
  tasks:
    - name: adding secondary group(s)
      ansible.builtin.user:
        name: "{{ myuser }}"
        groups: "{{ mygroups }}"
        append: true

execution

$ ansible-playbook -i virtualmachines/demo/inventory users_and_groups/user_group_addsecondary.yml
PLAY [user module demo] ***************************************************************************
TASK [Gathering Facts] ****************************************************************************
ok: [demo.example.com]
TASK [adding secondary groups] ********************************************************************
changed: [demo.example.com]
PLAY RECAP ****************************************************************************************
demo.example.com           : ok=2    changed=1    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0

before execution

$ ssh [email protected]
[[email protected] ~]$ sudo su
[[email protected] devops]# cat /etc/os-release 
NAME="Red Hat Enterprise Linux"
VERSION="8.5 (Ootpa)"
ID="rhel"
ID_LIKE="fedora"
VERSION_ID="8.5"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Red Hat Enterprise Linux 8.5 (Ootpa)"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:8::baseos"
HOME_URL="https://www.redhat.com/"
DOCUMENTATION_URL="https://access.redhat.com/documentation/red_hat_enterprise_linux/8/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 8"
REDHAT_BUGZILLA_PRODUCT_VERSION=8.5
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8.5"
[[email protected] devops]# getent passwd | grep example
example:x:1002:1002:Ansible example:/home/example:/bin/bash
[[email protected] devops]# id example
uid=1002(example) gid=1002(example) groups=1002(example),10(wheel)
[[email protected] devops]# groups example
example : example wheel
[[email protected] devops]# grep example /etc/group
wheel:x:10:example
example:x:1002:
[[email protected] devops]#

after execution

$ ssh [email protected]
[[email protected] ~]$ sudo su
[[email protected] devops]# id example
uid=1002(example) gid=1002(example) groups=1002(example),3(sys),4(adm),10(wheel)
[[email protected] devops]# groups example
example : example sys adm wheel
[[email protected] devops]# getent passwd | grep example
example:x:1002:1002:Ansible example:/home/example:/bin/bash
[[email protected] devops]# grep example /etc/group
sys:x:3:example
adm:x:4:example
wheel:x:10:example
example:x:1002:
[[email protected] devops]#