Continuous Integration and running builds on virgin machines?

Question

Two parts to this questions.

1) As part of our Continuous Integration build process i would like to install everything as-if it were a virgin machine. Martin folwler paper: http://martinfowler.com/articles/continuousIntegration.html

Does he mean that we take each (integration) build (clean machine) and installing ALL the necessary software to make the build work? I'm guess this is what he meant by "Single Command" build.

2) Which leads me nicely onto the next question. Is it possible to install programs using Powershell/Dos all through the command line? For example how would I install WinRar and possibly MySQL? (Winrar being a easy example, MySql complex).

Anyways, I am interested to hear from real-world practitioners of CI and how they approach their build processes.

Answer 1

In the latest CI environment I built, I installed and configured the toolchains and SDKs under a single directory tree and then created an ImageX WIM image of the tree. Each clean build would then mount the image, checkout sources from version control, build them, run tests etc. When unmounting, just remember to not commit the changes back to the image so that the image file stays clean.

Answer 2

For each of our builds with Zed we ensure a completely clean working environment, but assume that the entire tool-chain and utility applications are already installed on the machine.

If you really want to go to the level of virgin machine, then I would agree with laalto and look into VM. Setup your VM library to represent the different build environments/configurations that you will need for your product set, and load/start them on demand as you require builds for different products.

I think it is very important to always build from a clean working directory, but I'd question the real value of always trying to start with a bare OS and install everything from scratch for every build.