There are a few problems with using the install scripts on container based virtualizations like docker, openvz etc. For example even after you’re able to get it installed you might face an ENOSPC error,
Its best to install manually on them, for now! Or better yet, use a VM. We don’t yet completely support container based virtualization. However you can try it out, and if you can find and fix all the problems send PRs for the same 
And I now realized why swapon was failing. A container based environment is not true virtualization. Hence it cannot modify the kernel level stuff. For example in the above mentioned link, ENOSPC cannot be fixed from inside the container. The changes need to be made on the host machine. Same goes for swap on, you have to create swap area on the host machine and link it inside somehow. Same goes for SE Linux. All these are kernel parameters and cannot be modified from inside the container based environment.
However I still don’t know why creation of user was failing.
Also maybe next time mention that you’re using a conainer based system 