---
################################################################################
# Install Ansible's dependencies: python and lsb_release, required respectively 
# to run Ansible modules and gather Ansible facts.
#
# See also:
# - http://docs.ansible.com/ansible/intro_installation.html#managed-node-requirements
# - http://docs.ansible.com/ansible/setup_module.html
################################################################################

- name: check if python is installed (as required by ansible modules)
  raw: test -e /usr/bin/python
  register: is_python_installed
  failed_when: is_python_installed.rc not in [0, 1]
  changed_when: false  # never mutates state.

- name: install python if missing (as required by ansible modules)
  when: is_python_installed|failed  # skip otherwise
  raw: (test -e /usr/bin/apt-get && apt-get update && apt-get install -y python-minimal) || (test -e /usr/bin/yum && yum update && yum install -y python)
  changed_when: is_python_installed.rc == 1

- name: check if lsb_release is installed (as required for ansible facts)
  raw: test -e /usr/bin/lsb_release
  register: is_lsb_release_installed
  failed_when: is_lsb_release_installed.rc not in [0, 1]
  changed_when: false  # never mutates state.

- name: install lsb_release if missing (as required for ansible facts)
  when: is_lsb_release_installed|failed  # skip otherwise
  raw: (test -e /usr/bin/apt-get && apt-get install -y lsb_release) || (test -e /usr/bin/yum && yum install -y redhat-lsb-core)
  changed_when: is_lsb_release_installed.rc == 1

- setup:  # gather 'facts', i.e. compensates for 'gather_facts: false' in calling playbook.