Wikipedia is just recently in the process of adopting containers for a lot of services, however, up until recently everything pretty much operated on bare metal and many things, most notably the mediawiki web services are still on bare metal.
All the infrastructure configuration is managed with puppet and that's all in a public git repo:
All the infrastructure configuration is managed with puppet and that's all in a public git repo:
https://gerrit.wikimedia.org/g/operations/puppet/+/refs/head...
How I know: I worked for the Wikimedia Foundation for ~7 years, until February of this year.