Re: building local RPM-based Docker images

[Colin Walters <walters verbum org>]

On Wed, May 14, 2014 at 7:27 PM, Clayton Coleman <ccoleman redhat com> 
wrote:
> Seems like the pattern is a templated dockerfile, where you generate 
> the ADD at the same time you build.

Yeah, searching around the net, it seems like a lot of people are 
templating.

So here's what I did initially:

https://github.com/cgwalters/rpm-ostree/commit/97607f22d5d5408de4354beecb1355f2284be11a

You can see from the Dockerfile there's not a huge amount of 
interesting stuff going on there.

However, I have a slightly more complex version for -toolbox:

https://github.com/cgwalters/rpm-ostree-toolbox/blob/master/packaging/Dockerfile.in

For example, one thing that made this much more practical was line 5, 
where I have a manual copy of the RPM dependencies to create a caching 
layer.  Otherwise I had to wait for a yum reinstall of all of the 
dependencies (and with libguestfs, there are a lot).

It seems like other projects are coming at this from the other end 
where you have a simple "Base" "Framework" "App" triple layer.  
Conceptually I'm inventing my own "Framework" here as the set of RPM 
dependencies of my app.

So, the clear next step is to generate separate "normal" Dockerfile 
which is just
yum -y install myapp
that I can use *after* I've tested it locally, or something like that.

Anyone else doing stuff in this area?