Increasingly, when testing new services, users rely on virtual machines. This should be no surprise - it is for many of the same reasons OpenStack itself is successful :)
We have structured the install guide such that it is not a "one click", nor a full "production" installation, but something in between. A lightweight learning experience, aimed to provide enough knowledge that one can go on, knowing where the configuration files are, which daemons are around for the services, and how aspects of OpenStack such as the service catalog work.
How much or how little background information, or what knowledge level to assume is always a challenge with this document. So it might be that this bug should not be solved, or a speparate companion appendix should be created rather than any in-line modifications. I'm merely putting it up for consideration :)
A standard virtual machine typically comes with:
* 1 interface, configured with an address from DHCP, that accesses internet through a NAT
A current OpenStack installation using the install guide requires machines to have:
* 1 interface with a static IP, with internet access through NAT
* 1 interface with no IP address, that has "direct" internet access
To be clear, I don't think there's a problem with the requirements. This bug is about the difficulty of realising them on a VM and whether we should do anything to assist.
To successfully set this up in a normal-ish vm environment, the reader will have to use brctl to make two new bridges and then use iptables to make a NAT between each bridge and the internet, and work with the route command so they can access the hosts from their desktop. They'll then need to renumber the VM's "regular" interface (or keep it as an additional one) as part of the install.
If you've done it before - reasonably straightforward. If you're learning about linux networking at the same time as OpenStack, it can be quite a challenge.
In general, different hypervisors implement networking in different ways. To implement your suggestion, we would need to provide instructions that specify a hypervisor networking configuration that may only apply to a small percentage of our audience. Furthermore, we would need to test the entire installation guide and triage bugs using both bare metal and virtual machines.