Python API
==========

There are several interesting ways to use Ansible from an API perspective.   You can use
the Ansible python API to control nodes, you can extend Ansible to respond to various python events,
and you can plug in inventory data from external data sources.  Ansible is written in its own
API so you have a considerable amount of power across the board.  This chapter discusses the Python API.

.. contents:: `Table of contents`
   :depth: 2

Python API
----------

The Python API is very powerful, and is how the ansible CLI and ansible-playbook
are implemented.

It's pretty simple::

    import ansible.runner

    runner = ansible.runner.Runner(
       module_name='ping',
       module_args='',
       pattern='web*',
       forks=10
    )
    datastructure = runner.run()

The run method returns results per host, grouped by whether they
could be contacted or not.  Return types are module specific, as
expressed in the 'ansible-modules' documentation.::

    {
        "dark" : {
           "web1.example.com" : "failure message"
        },
        "contacted" : {
           "web2.example.com" : 1
        }
    }

A module can return any type of JSON data it wants, so Ansible can
be used as a framework to rapidly build powerful applications and scripts.

Detailed API Example
````````````````````

The following script prints out the uptime information for all hosts::

    #!/usr/bin/python

    import ansible.runner
    import sys

    # construct the ansible runner and execute on all hosts
    results = ansible.runner.Runner(
        pattern='*', forks=10,
        module_name='command', module_args='/usr/bin/uptime',
    ).run()

    if results is None:
       print "No hosts found"
       sys.exit(1)

    print "UP ***********"
    for (hostname, result) in results['contacted'].items():
        if not 'failed' in result:
            print "%s >>> %s" % (hostname, result['stdout'])

    print "FAILED *******"
    for (hostname, result) in results['contacted'].items():
        if 'failed' in result:
            print "%s >>> %s" % (hostname, result['msg'])

    print "DOWN *********"
    for (hostname, result) in results['dark'].items():
        print "%s >>> %s" % (hostname, result)

Advanced programmers may also wish to read the source to ansible itself, for
it uses the Runner() API (with all available options) to implement the
command line tools ``ansible`` and ``ansible-playbook``.

