Get Ansible to work on bare Ubuntu 16.04 without python 2.7

ansible-bootstrap-ubuntu-16.04.yml

# Add this snippet to the top of your playbook. 
# It will install python2 if missing (but checks first so no expensive repeated apt updates)
# [email protected]

- hosts: all
  gather_facts: False
  
  tasks:
  - name: install python 2
    raw: test -e /usr/bin/python || (apt -y update && apt install -y python-minimal)

Why is the raw command necessary for this? I've been having trouble running this lately (likely due to @mahlingam's comment above), and I found that this seems to work for me:

- hosts: all
  become: true
  become_user: root
  become_method: sudo
  gather_facts: no
  pre_tasks:
    - name: Install python for Ansible
      apt:
        update_cache: yes
        name:
          - python-minimal
    - setup: # aka gather_facts
  tasks:
    ...

Just wondering if there's a reason not to do this

Just wondering if there's a reason not to do this

Yep, I think it's simply that a target server without python installed, is unable to run normal ansible task steps. Using 'raw' side-steps the need for python.

PS I think bootstrapping a Python 2 installation is now likely to be unnecessary, since Ansible 2.8+ will auto-detect a suitable Python interpreter to use anyway.

https://docs.ansible.com/ansible/latest/reference_appendices/interpreter_discovery.html

If anyone is looking for a solution for Ubuntu 20.04 - change python-minimal to python2-minimal.