Comment 4 for bug 1594389

I'd like to see this, but instead of configuring a proxy on the undercloud, optionally do it on the virthost, then the data could persist between quickstart runs.

In general quickstart support for proxying and/or locally mirroring things seems fairly fragmented, IMO it'd be great if we could streamline this as it does download a ton of data atm, which is particularly annoying when testing quickstart patches that involve repeatedly re-running quickstart (yes I know there's a working dir, but IME things don't always work unless you clean that, so just mirroring/proxying the downloaded stuff would probably be better IMO)