Using Runner as a Python Module Interface to Ansible

Ansible Runner is intended to provide a directly importable and usable API for interfacing with Ansible itself and exposes a few helper interfaces.

The modules center around the Runner object. The helper methods will return an instance of this object which provides an interface to the results of executing the Ansible command.

Ansible Runner itself is a wrapper around Ansible execution and so adds plugins and interfaces to the system in order to gather extra information and process/store it for use later.

Helper Interfaces

The helper interfaces provides a quick way of supplying the recommended inputs in order to launch a Runner process. These interfaces also allow overriding and providing inputs beyond the scope of what the standalone or container interfaces support. You can see a full list of the inputs in the linked module documentation.

run() helper function

ansible_runner.interface.run()

When called, this function will take the inputs (either provided as direct inputs to the function or from the Runner Input Directory Hierarchy), and execute Ansible. It will run in the foreground and return the Runner object when finished.

run_async() helper function

ansible_runner.interface.run_async()

Takes the same arguments as ansible_runner.interface.run() but will launch Ansible asynchronously and return a tuple containing the thread object and a Runner object. The Runner object can be inspected during execution.

The Runner object

The Runner object is returned as part of the execution of Ansible itself. Since it wraps both execution and output it has some helper methods for inspecting the results. Other than the methods and indirect properties, the instance of the object itself contains two direct properties:

  • rc will represent the actual return code of the Ansible process

  • status will represent the state and can be one of:

    • unstarted: This is a very brief state where the Runner task has been created but hasn’t actually started yet.

    • successful: The ansible process finished successfully.

    • failed: The ansible process failed.

Runner.stdout

The Runner object contains a property ansible_runner.runner.Runner.stdout which will return an open file handle containing the stdout of the Ansible process.

Runner.events

ansible_runner.runner.Runner.events is a generator that will return the Playbook and Host Events as Python dict objects.

Runner.stats

ansible_runner.runner.Runner.stats is a property that will return the final playbook stats event from Ansible in the form of a Python dict

Runner.host_events

ansible_runner.runner.Runner.host_events() is a method that, given a hostname, will return a list of only Ansible event data executed on that Host.

Runner.get_fact_cache

ansible_runner.runner.Runner.get_fact_cache() is a method that, given a hostname, will return a dictionary containing the Facts stored for that host during execution.

Runner.event_handler

A function passed to __init__ of Runner, this is invoked every time an Ansible event is received. You can use this to inspect/process/handle events as they come out of Ansible.

Runner.cancel_callback

A function passed to __init__ of Runner, and to the ansible_runner.interface.run() interface functions. This function will be called for every iteration of the ansible_runner.interface.run() event loop and should return True to inform Runner cancel and shutdown the Ansible process or False to allow it to continue.

Runner.finished_callback

A function passed to __init__ of Runner, and to the ansible_runner.interface.run() interface functions. This function will be called immediately before the Runner event loop finishes once Ansible has been shut down.

Runner.status_handler

A function passed to __init__ of Runner and to the ansible_runner.interface.run() interface functions. This function will be called any time the status changes, expected values are:

  • starting: Preparing to start but hasn’t started running yet

  • running: The Ansible task is running

  • canceled: The task was manually canceled either via callback or the cli

  • timeout: The timeout configured in Runner Settings was reached (see env/settings - Settings for Runner itself)

  • failed: The Ansible process failed

Usage examples

import ansible_runner
r = ansible_runner.run(private_data_dir='/tmp/demo', playbook='test.yml')
print("{}: {}".format(r.status, r.rc))
# successful: 0
for each_host_event in r.events:
    print(each_host_event['event'])
print("Final status:")
print(r.stats)

import ansible_runner
r = ansible_runner.run(private_data_dir='/tmp/demo', host_pattern='localhost', module='shell', module_args='whoami')
print("{}: {}".format(r.status, r.rc))
# successful: 0
for each_host_event in r.events:
    print(each_host_event['event'])
print("Final status:")
print(r.stats)

Providing custom behavior and inputs

TODO

The helper methods are just one possible entrypoint, extending the classes used by these helper methods can allow a lot more custom behavior and functionality.

Show:

  • How Runner Config is used and how overriding the methods and behavior can work

  • Show how custom cancel and status callbacks can be supplied.