ansible playbook, different user by operating system

Solution 1:

The docs mention performing tasks just for particular operating systems. You could tweak this to set the user for each OS. For example

- hosts: CentOS
  user: centos
  tasks:
  - # some tasks

- hosts: Debian
  user: default
  - # some tasks

- hosts: Ubuntu
  user: ubuntu
  - # some tasks

In the source, it appears that these operating systems are supported, though I could not confirm this in the official documentation at the time of this writing.

• RedHat
• Fedora
• CentOS
• Scientific
• SLC
• Ascendos
• CloudLinux
• PSBM
• OracleLinux
• OVS
• OEL
• Amazon
• XenServer
• Ubuntu
• Debian
• SLES
• SLED
• OpenSuSE
• SuSE
• Gentoo
• ArchLinux
• Mandriva
• Mandrake
• Solaris
• Nexenta
• OmniOS
• OpenIndiana
• SmartOS

You can also have per-OS variables defined in vars/<os-name>.yaml files and conditionally use them using the ansible_os_family template variable as shown here.

Solution 2:

The CentOS and so on isn't automatic. It's a group over ansible provided variable. Here is a full example, dealing with CentOS plus VM or not VM.

---
- name: RG Ansible for ALL
  hosts: all
  tasks:
  - name: group by OS versions
    group_by: key="{{ ansible_distribution }}_{{ ansible_distribution_version.split('.')[0] }}"
  - name: group by physical/virtual machine
    group_by: key="{{ ansible_virtualization_role }}"
...
- name: RG Ansible for CentOS 6
  hosts: CentOS_6
  gather_facts: false
  tasks:
...
- name: RG Ansible for CentOS 5
  hosts: CentOS_5
  gather_facts: false
  tasks:

- name: RG Ansible for VM
  hosts: guest
  gather_facts: false
  tasks:
  - service: name=acpid state=stopped enabled=no
  - service: name=cpuspeed state=stopped enabled=no

Solution 3:

Specify the user on the command line:

ansible-playbook foo.yml --extra-vars "user=bar"

-----
- user: '{{ user }}'

Specify a different user per host-group in /etc/ansible/hosts

[targets]

localhost              ansible_connection=local
other1.example.com     ansible_connection=ssh        ansible_ssh_user=mpdehaan
other2.example.com     ansible_connection=ssh        ansible_ssh_user=mdehaan