Ansible callback plugin for human-readable result logging - http://blog.cliffano.com/2014/04/06/human-readable-ansible-playbook-log-output-using-callback-plugin/

human_log.py

# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

# Documentation: http://blog.cliffano.com/2014/04/06/human-readable-ansible-playbook-log-output-using-callback-plugin/
# Improved and made compatible with Ansible v2
# Original Source: https://gist.github.com/cliffano/9868180
# First Modified Version: https://gist.github.com/dmsimard/cd706de198c85a8255f6
# Second Modified Version: https://gist.github.com/asmartin/c03bdeeff6854a06bfb779cf6d2289bb
# This Version: https://gist.github.com/shanedroid/beca4902c6a1af1bd23b3c92f118f6ed
#
# Changelog:
# 2018-02-20 - [shanedroid] added updated fix for observed errors as per observations/fixes made by [mark-wagner] https://github.com/mark-wagner
#              SEE: https://gist.github.com/asmartin/c03bdeeff6854a06bfb779cf6d2289bb#gistcomment-2195701

from __future__ import (absolute_import, division, print_function)
from ansible.utils.unsafe_proxy import AnsibleUnsafeText
__metaclass__ = type

from ansible.plugins.callback import CallbackBase
try:
    import simplejson as json
except ImportError:
    import json

# Fields to reformat output for
FIELDS = ['cmd', 'command', 'start', 'end', 'delta', 'msg', 'stdout',
          'stderr', 'results']
NO_LOG_FIELDS = ['cmd', 'command', 'msg', 'stdout', 'stderr', 'results']


class CallbackModule(CallbackBase):
    def __init__(self, *args, **kwargs):
        super(CallbackModule, self).__init__(*args, **kwargs)
        self.task = None
        self.play = None

    def human_log(self, data):
        if type(data) == dict:
            for field in FIELDS:
                if field in data.keys() and data[field]:
                    if field in NO_LOG_FIELDS and getattr(self.task, 'no_log', False):
                        print("\n{0}: <output hidden via no_log>".format(field))
                    else:
                        output = self._format_output(data[field])
                        print("\n{0}: {1}".format(field, output.replace("\\n","\n")))

    def _format_output(self, output):
        # Strip unicode
        if type(output) == unicode or type(output) == AnsibleUnsafeText:
            output = output.encode('ascii', 'replace')

        # If output is a dict
        if type(output) == dict:
            return json.dumps(output, indent=2)

        # If output is a list of dicts
        if type(output) == list and type(output[0]) == dict:
            # This gets a little complicated because it potentially means
            # nested results, usually because of with_items.
            real_output = list()
            for index, item in enumerate(output):
                copy = item
                if type(item) == dict:
                    for field in FIELDS:
                        if field in item.keys():
                            copy[field] = self._format_output(item[field])
                real_output.append(copy)
            return json.dumps(output, indent=2)

        # If output is a list of strings
        if type(output) == list and type(output[0]) != dict:
            # Strip newline characters
            real_output = list()
            for item in output:
                if "\n" in item:
                    for string in item.split("\n"):
                        real_output.append(string)
                else:
                    real_output.append(item)

            # Reformat lists with line breaks only if the total length is
            # >75 chars
            if len("".join(real_output)) > 75:
                return "\n" + "\n".join(real_output)
            else:
                return " ".join(real_output)

        # Otherwise it's a string, just return it
        return output

    def on_any(self, *args, **kwargs):
        pass

    def runner_on_failed(self, host, res, ignore_errors=False):
        self.human_log(res)

    def runner_on_ok(self, host, res):
        self.human_log(res)


    def runner_on_error(self, host, msg):
        pass

    def runner_on_skipped(self, host, item=None):
        pass

    def runner_on_unreachable(self, host, res):
        self.human_log(res)

    def runner_on_no_hosts(self):
        pass

    def runner_on_async_poll(self, host, res, jid, clock):
        self.human_log(res)

    def runner_on_async_ok(self, host, res, jid):
        self.human_log(res)

    def runner_on_async_failed(self, host, res, jid):
        self.human_log(res)

    def playbook_on_start(self):
        pass

    def playbook_on_notify(self, host, handler):
        pass

    def playbook_on_no_hosts_matched(self):
        pass

    def playbook_on_no_hosts_remaining(self):
        pass

    def playbook_on_task_start(self, name, is_conditional):
        pass

    def playbook_on_vars_prompt(self, varname, private=True, prompt=None,
                                encrypt=None, confirm=False, salt_size=None,
                                salt=None, default=None):
        pass

    def playbook_on_setup(self):
        pass

    def playbook_on_import_for_host(self, host, imported_file):
        pass

    def playbook_on_not_import_for_host(self, host, missing_file):
        pass

    def playbook_on_play_start(self, pattern):
        pass

    def playbook_on_stats(self, stats):
        pass

    def v2_playbook_on_play_start(self, play):
        self.play = play

    def v2_playbook_on_task_start(self, task, is_conditional):
        self.task = task

verified working as callback plugin with ansible 2.4.3.0

ansible.cfg :

[defaults]
callback_plugins = ./plugins/callback
callback_whitelist = datadog_callback, human_log, profile_tasks, slack, timer

Example dir layout of ansible project:

├── README.md
├── Vagrantfile
├── ansible.cfg
├── deploy.yml
├── environments/*
├── playbooks/*
├── plugins
│   └── callback
│       ├── datadog_callback.py
│       ├── datadog_callback.pyc
│       ├── datadog_callback.yml
│       ├── human_log.py
│       └── human_log.pyc
├── requirements.txt
├── requirements.yml
├── roles/*
├── site.yml
└── vault_password.py

also worth noting that this callback plugin is no longer needed as the debug plugin can be used by default now, I have just switched to using that instead:

ansible/ansible#27078 (comment)
https://github.com/ansible/ansible/blob/v2.4.3.0-1/lib/ansible/plugins/callback/debug.py
https://gist.github.com/cliffano/9868180#gistcomment-1915662