[ale] [barely OT] Containerization

[Jeff Hubbs]

OK, everyone -

I've seen a lot of talk about Docker go by. I am needing to look at 
engineering some "distributed modular containerization" of apps and 
perhaps whole OS instances. I just had a situation develop on the job 
where a MongoDB instance needed to be available for casual use (i.e., 
for education purposes) on Windows laptops. I was able to generate a 
tiny Linux VM to do that; set up for use in VirtualBox using a host-only 
adapter, the instance was nice and contained (by default MongoDB goes in 
with no authentication set up at all - it's just *there*). But 
trafficking in whole VMs seems like a lot of weight to throw around, 
even though I managed to get this particular VM's export file down to 1 
gig, There are also lots of guardrails to smack into, like the limited 
size of the virtual disk, and other things like making sure the "guest 
addition" daemon that makes sure the clock stays synced and so forth 
that I would just as soon not have to deal with.

What I envision is something where MongoDB lives in one container and, 
say, another container with RStudio with all the needed packages, 
extensions, etc. and yet another with such-and-such Python version and 
all its intended packages preloaded can be flown into a relatively 
unmodified OS instance (assume Windows or OS X) and networked together 
so that the apps in the containers can see each other; perhaps just one 
needs to be able to reach out to the host machine's network or possibly 
other machines on the host machine's network needs to able to see one or 
more of the containers. Is Docker a fit for what I'm thinking of, or 
would something else be, or do I need to modify my thinking?

- Jeff