I used docker,Marathon and Mesos in my server infrastructure. I want to change few things in Marathon UI. Is it possible? If yes then from where I can find the installed codebase of Marathon UI.?
Marathon is open source on GitHub so you could pull the source, change it how you want, and build it yourself, customised.
The UI is even a separate GitHub project so you can change it separately.
https://github.com/mesosphere/marathon https://github.com/mesosphere/marathon-ui/tree/master/src
The Marathon Readme on Github has the instructions to build from source:
"To build Marathon from source, check out this repo and submodules and use sbt to build a JAR:"
git clone --recursive https://github.com/mesosphere/marathon.git
cd marathon
sbt assembly
"Run ./bin/build-distribution
to package Marathon as an executable JAR (optional)."