On this page https://github.com/mendix/docker-mendix-buildpack you can read what to change for ubuntu.
One example
ROOTFS_IMAGE is a type of rootfs image. Defaults to mendix/rootfs:ubi8
(Red Hat Universal Base Image 8). To use Ubuntu 18.04, change this to mendix/rootfs:bionic
. It's also possible to use a custom rootfs image as described in Advanced feature: full-build.
Hello
You can try the procedure described at:
Update: Containerize Mendix Applications | by Vinicius Strugata Ambrosio | Medium