A few short words on the update of my Mule ESB Community Edition Docker images, to which I have included an image for the version 4 release candidate.
The OpenJDK official repository contains a wealth of Docker images based on Alpine Linux, Debian and even Windows server for those with Windows 10 or Windows Server 2016 Docker hosts. I chose a base image based on Debian Stretch (Debian 9) which has been slimmed down for used in containers and OpenJDK JRE 1.8u141. This combination allowed Mule ESB 4 to start properly.
Seeing that the size of the Debian-based Mule Docker image is even smaller than the Alpine Linux based Docker images, I will look into making the Docker images for the other versions of Mule ESB Community Edition based on Debian as well. For me, this will have the benefit of a closed match with my development environment in which I use Ubuntu Linux.
Regretfully, I have not had time to try out Mule ESB version 4 yet as I am working on a project that uses Spring Integration 5, which I by the way really can recommend, but I think there will be an opportunity in a not-too-distant future.