Ansible callback plugin with best of selective and debug callbacks

selective_debug.py

# (c) 2017 Ansible Project
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

DOCUMENTATION = '''
    callback: selective_debug
    type: stdout
    short_description: selective formatted stdout/stderr display
    description:
      - Use this callback like selective callback and get debug callback style stdout
    version_added: "not yet added"
    extends_documentation_fragment:
      - default_callback
    requirements:
      - set as stdout in configuration
'''

from ansible.plugins.callback.default import CallbackModule as CallbackModule_default


class CallbackModule(CallbackModule_default):  # pylint: disable=too-few-public-methods,no-init
    '''
    Override for the default callback module.

    Render std err/out outside of the rest of the result which it prints with
    indentation.
    '''
    CALLBACK_VERSION = 2.0
    CALLBACK_TYPE = 'stdout'
    CALLBACK_NAME = 'selective_debug'

    def v2_playbook_on_task_start(self, task, **kwargs):
        pass

    def v2_runner_on_ok(self, result, **kwargs):
        if 'print_action' in result._task.tags or self._display.verbosity > 1:
            print(self._dump_results(result))
        else:
            print('.')

    def _dump_results(self, original_result, indent=None, sort_keys=True, keep_invocation=False):
        '''Return the text to output for a result.'''

        # original_result is what playbook events receive ... of these, we use only _result and _task (for its name)
        result = original_result._result
        task_name = original_result._task.get_name()

        # Enable JSON identation
        result['_ansible_verbose_always'] = True

        save = {}
        # for debug module, avoid printing changed: false every time
        for key in ['stdout', 'stdout_lines', 'stderr', 'stderr_lines', 'msg', 'module_stdout', 'module_stderr', 'changed']:
            if key in result:
                save[key] = result.pop(key)

        output = CallbackModule_default._dump_results(self, result)
        # no need to print empty map
        if output == '{}':
            output = ''

        for key in ['stdout', 'stderr', 'msg', 'module_stdout', 'module_stderr']:
            if key in save and save[key]:
                output += '[%s] %s:\n%s' % (task_name, key, save[key])

        for key, value in save.items():
            result[key] = value

        return output

1. Place under plugins/callback.
2. Configure ansible to use it. One way is to have in ansible.cfg:

[defaults]
callback_whitelist = selective
stdout_callback = selective

3. For each task you wish to be shown, add tag print_action. Example:

- debug: msg="foobar"
  tags: [print_action]