Dear community. I have just finished my work to upgrade Docker version to 18.06. https://github.com/apache/incubator-openwhisk/pull/4430
With this change, it would be required for all target hosts to install Docker-18.06. So this is a breaking change. Please reply to this thread if there are any issues in downstream. This PR would get merged in 48 hours if there is no objection based on silent assent. Thanks Best Regards Dominic
