okd/roles/lib_utils/callback_plugins/aa_version_requirement.py

#!/usr/bin/python

"""
This callback plugin verifies the required minimum version of Ansible
is installed for proper operation of the OpenShift Ansible Installer.
The plugin is named with leading `aa_` to ensure this plugin is loaded
first (alphanumerically) by Ansible.
"""
import sys
from distutils import version

from ansible import __version__

if __version__ < '2.0':
    # pylint: disable=import-error,no-name-in-module
    # Disabled because pylint warns when Ansible v2 is installed
    from ansible.callbacks import display as pre2_display
    CallbackBase = object

    def display(*args, **kwargs):
        """Set up display function for pre Ansible v2"""
        pre2_display(*args, **kwargs)
else:
    from ansible.plugins.callback import CallbackBase
    from ansible.utils.display import Display

    def display(*args, **kwargs):
        """Set up display function for Ansible v2"""
        display_instance = Display()
        display_instance.display(*args, **kwargs)


# Set to minimum required Ansible version
REQUIRED_VERSION = version.StrictVersion('2.5.7')
DESCRIPTION = "Supported versions: %s or newer" % REQUIRED_VERSION


def version_requirement(ver):
    """Test for minimum required version"""
    if not isinstance(ver, version.StrictVersion):
        ver = version.StrictVersion(ver)
    return ver >= REQUIRED_VERSION


class CallbackModule(CallbackBase):
    """
    Ansible callback plugin
    """

    CALLBACK_VERSION = 1.0
    CALLBACK_NAME = 'version_requirement'

    def __init__(self):
        """
        Version verification is performed in __init__ to catch the
        requirement early in the execution of Ansible and fail gracefully
        """
        super(CallbackModule, self).__init__()

        if not version_requirement(__version__):
            display(
                'FATAL: Current Ansible version (%s) is not supported. %s'
                % (__version__, DESCRIPTION), color='red')
            sys.exit(1)