[RFC PATCH] docker: Add support for using eatmydata in the database

[Stephen Finucane]

On Fri, 2019-05-03 at 17:33 +1000, Russell Currey wrote:
> When running tox on a VM with presumably pretty busy spinning disks,
> using eatmydata with the database took running one configuration's test
> suite from (no exaggeration) 20 minutes down to 60 seconds.
> 
> It makes a huge difference to test speed, so we should make it easily
> available for developers.  The primary motivation here was to
> automatically test each patch in a timeframe that isn't insane.
> 
> Open to ideas on how to organise this, whether we do it for MySQL too
> (which we probably should), whether the base directory should have these
> files in it, what to call the Dockerfile, etc.  I think it's a good
> thing to have in the repo, though.
> 
> Signed-off-by: Russell Currey <ruscur at russell.cc>

What are the implications of doing this _from a development
perspective_ and can we do this by default in the two existing docker-
compose files? Given that we're only talking about a development
environmnent where information presumably isn't that important allied
to the fact that we have the ability to back up and restore from known
good points (the dbbackup, dbrestore management commands,
respectively), do we need to be seriously concerned about dataloss?

Stephen