How to preserve build environment during product lifecycle

Question

What are best practices in recording build/test machine(s) setup during the life time of a project? If you need to provide a patch for previous version of your product, you likely need to reload the same compiler and support tools to re-issue the patched release. What and how do you record? The obvious things are:

the OS version and patch level,
compiler/IDE version and patch level
3rd party tools/libraries.

My first thought is to keep a log file of all the requirements. This log file would go into your VCS.

Answer 1

I'm using maven for java with the enforcerer plugin so all of these things are stored in my project object model, even the version of maven itself which is required. As long as I manage to get the proper version from version control I'm home free.

Answer 2

3rd party tools and libraries go in version control along with everything else; we have a libs tree that goes under our VCS trunk right next to our app tree, so it gets included with any branches or tags that we create. The one wrinkle I haven't yet solved is Windows tools and libraries that require their own installers instead of running out of whatever directory VCS gives them.

For OS and compiler, I'd recommend creating a VM for each release if you can't install multiple compiler versions in parallel. Then your project wiki can document which VM and which compiler version to use for a given build. This isn't automatic like your log file would be, but it provides a ready-to-go environment (instead of potentially having to reinstall a machine to match your log file). Some projects check their entire compiler into version control, but this seems overkill to me (and doesn't play well with IDEs and compilers that need their own installers).

We don't track patch levels for the OS and compiler. I realize that it's possible that a patch would break or change something, but the chance seems so low that the cost-benefit ratio just isn't there.

Answer 3

VMWare Virtualization(or other similar products) are ideal for this type of thing. Build an entire development/build/ or test environment, and leave it setup just for that purpose. You can take the image off-line, back it up to a DVD and simply turn it back on when you need it.