[Reviewer: Mat] Fix up ellis container build for non-aufs storage drivers

[sebrexmetaswitch]

mysql can't start on docker hosts running a non-aufs storage driver. Touching all the files under /var/lib/mysql is a workaround for this.

I've tested that this fix resolves the ellis build issues we were seeing periodically (it turns out that it depends on the storage driver your docker host is using)

[MatMeredith]

Generally looks good to me :-) A few questions / suggestions though...

• Why is this a problem here and not elsewhere (if indeed it isn't?) -- is there something about mysql that makes it uniquely susceptible to it? Or is it likely to cause us other problems too?
• Can we add a comment to the Dockerfile please? Someone else is going to have no idea why we're doing this here.
• Presumably you'll update https://github.com/Metaswitch/clearwater-docker/issues/74 once we've committed the fix?

[sebrexmetaswitch]

Why is this a problem here and not elsewhere (if indeed it isn't?) -- is there something about mysql that makes it uniquely susceptible to it? Or is it likely to cause us other problems too?

It's not mysql-specific, but only some applications are affected by this issue, and mysql is one of them. I'll see if I can find a better explanation somewhere (there are a bunch of them in various reports of mysql not working nicely on overlay or overlay2)

Can we add a comment to the Dockerfile please? Someone else is going to have no idea why we're doing this here.

Will do :)

Presumably you'll update #74 once we've committed the fix?

Now I will

[sebrexmetaswitch]

https://github.com/docker/for-linux/issues/72#issuecomment-319904698 Is a good explanation of the mysql issue