Ruminations of J.net idle rants and ramblings of a code monkey

TFS 2010 Lab Management – Core Components

TFS 2010

I went to the “Next Generation Testing with Visual Studio 2010” event in Houston yesterday. And … while it is somewhat strange going to a Microsoft event where I’m a “mere attendee” … I did really enjoy the experience. There was a TON of information there and, for me, one of the very coolest technology revolved around lab management and the automation of Hyper-V based environments to do this. Abel (I hope that I spelled his name correctly) talked very deeply and extensively about his experience working with Lab Manager; very good stuff as he talked about real-world challenges around this. Plus he’s a biker … he and I chatted for quite some time after the event about motorcycles and motorcycling and that, in itself, is worth 20 points (out of 100) in my book.

One thing that he mentioned was the cost of copying VHD’s. There is only so much that can be done about that but … it struck me … as he was talking about it, it seemed that he was using his test servers as AD controllers. Maybe not … but the expense of AD controllers, etc. … was mentioned. And yes, little things like AD controllers (and DNS and DHCP) are very important when creating a dev/test environment. And then … and this may be just me … I like to keep dev/test environments as isolated as possible from production environments. A dev/test environment is meant to be blown up. It should be a place where crazy what-if scenarios (as well as normal testing) can be tried and evaluated without any fear of disrupting real work.  This includes AD domains … the test environment should have its own, dedicated AD. If there is a trust, then it’s a one-way trust and all traffic goes through a firewall between test and production environments. For Lab Management to work effectively and smoothly, you’ll need to do this.

This type of environment is hard to set up. TFS 2010 certainly makes the test virtual servers easy to set up and configure but it doesn’t seem to help with the core networking services that need to be there. But then, if I was a PM on that team, I’d put that task well “out of scope”. Probably forever … putting that “in scope” would require dealing with a core network environment that is completely unpredictable. That’s a recipe for Ugly.

But … configure the core network services and it’s all easier. Core network services include Active Directory (authT and authZ), DNS (name resolution), DHCP (IP Address independence) and RRAS (routing outside the test network). These are core network services that developers just expect to “work” – as well they should – but most developers never actually work with them. I learned this stuff “way back in the day” when you needed to understand the details of the underlying specs (can you say IUnknown?) to debug stuff. Fortunately, development has moved beyond the point where that is important on a daily basis. So … some details …

Windows Server 2008+ Server Core

It doesn’t matter if it’s Win2K8 or 2K8 R2. Server Core is your friend for any and all test environments. Create a virtual machine with Server Core and you’ve got AD, DNS and DHCP services for your test environment at a pretty low (virtual machine) cost. I run my server core VM at 256MB … I’ve tried less but it didn’t work well; 256MB seems to be the (practical) lower limit.

On this Server Core VM, add Active Directory Services, DNS Services and DHCP Services. It’s all command-line stuff that’s pretty well documented on TechNet. Connect to the Server Core instance with remote administration tools and set your DNS and DHCP environments up. Dealing with IP settings on individual machines with static addresses is far too painful and time-consuming for an effective test environment. Plus, I can never remember what IP is where anyway. Then, set this little Server Core VM to run all the time. Set all of your virtual machines to use your internal network with DHCP enabled. If you do/want a static address, use DHCP to create a reservation that assigns the same IP address to the same NIC based on the physical (MAC) address.

SysPrep

For your virtual machines, Sysprep is your friend. Setting up the core OS can be a pain, especially when the same roles and role services are needed over and over and over and over again. Wouldn’t it be nice to just do all of this common stuff once? Sysprep lets you do that … set up your server roles (Application Server, DNS, DHCP, IIS …) and then run sysprep (C:\%System32%\Sysprep\sysprep.exe). Select “Enter System Out-of-Box Experience” with “Generalize” checked. Save the VHD and use it as the base VHD for your test servers. Not differencing disks but a copy-rename-attach process. Then use your “sysprep’d” VHD to start your test virtual machines. They will go through a mini-setup and then you’ll have a running server that’s ready for its specific functionality in just a couple of minutes. Tip: when you are creating your sysprep’d image, make sure that you apply all of the updates before sysprepping. It won’t make anything break, but it’s helpful to have all of them already applied. And … you can also install some software before sysprepping. Antivirus, Visual Studio and Office are my typical candidates; I do try to avoid server products (i.e Sql Server, MOSS, etc.) in the sysprepped image. Be prepared to rev your base Sysprep’d image from time to time, usually with just new updates.

RRAS

RRAS stands for “Routing and Remote Access Services”. In Windows Server 2008, this is under “Network Policy and Access Services”. This allows you to bridge a private virtual network with the public Internet. It also allows you to route between two different isolated test networks. Finally, you can use it to allow access to wireless networks from a Hyper-V virtual network. Install NPAS on the host machine and set it up as either a regular router for a complex, enterprise implementation with domain trusts and the like or as a NAT router just to get Internet access for your virtual machines. Just to repeat … you can also use this to allow Hyper-V virtual networks to use a wireless connection for connecting to the Internet.

All of this … I won’t say it’s simple. But it’s really not all that hard, either … there are a lot of “dotting i’s and crossing t’s”. It helps – tremendously – if you know the basics of how networking, TCP/IP and routing work. You do not need to know this in the depth required to implement a 30,000+ desktop Active Directory implementation; that’s a whole different ballgame.