This is an open discussion, since I’m far from an expert on ansible.
However, since I often run some commands on a lot of host, I’ve written a small callback plugin that summarize output on stdout and stderr.
I need this callback to be called when running ansible (not the playbook), since I only run once a command, and forget it after that.
So I copied the “callbacks.load_callback_plugins()” from ansible-playbook. See the GitHub pull request to see it.
To avoid breaking user experience that are not used to callback in the ansible command, it may be a good idea to implement as an option, e.g. “ansible --callbacks …”
I hope to gather comments on this
Adrien