[ale] Docker containers as a desktop environment

[Alex Carver]

One thing I haven't been able to find is how to create a docker
container in the first place from scratch.  Every tutorial has you
downloading someone's container from somewhere.

If I wanted to experiment with running let's say a browser within a
container on any OS, where can you go to find out how to build all of
that?  At the moment I just spin up VM's but if containers really are a
little lighter on the system than a full VM, I wouldn't mind trying it
out just for browsers.

It seems to me, though, there's a slight inflexibility in the docker
method versus VM method in terms of updating and/or modifications.  For
example, if I create a brand new VM, install a bare OS and then install
the browser, I can possibly go back in later and add something I forgot
(e.g. Java, flash, etc.) just by using the guest OS's install methods.
The new data is merged in right away and the next time I start that VM
those changes are made.  My understanding with the Docker method is that
everything has to be installed either in the original image or on the
fly by the docker container script as the image starts but, again, this
is relying on someone else's docker-ready stuff.

If anyone has pointers on this kind of thing I'd like to see them and
try it out.