We have a really old server with ubuntu 10, and the plan is to move all the sites to a a newer Ubuntu 16 (virtual) machine (64bits).
The server has a lot (≈50) of old sites (some maybe 15 years).
I think one is 2.5.x, others are 'everything from 3.x to 5.0.
Every Zope has a few Plone sites, so there are about 15 Zope installation (using pythons from 2.4 to 2.7)
Some zope-instances have been installed with its own python ( probably python2.6) and a lot does not have a 'bootstrap.py' file.
All the sites are small, most are installed as standalone (and they dont need varnish / cache in front).
The plan is to move them from server A to server B, then upgrade server A, so we are sure they they are running while upgrading, and if 'something goes wrong'.
Any suggestions on how to do this the least painful way ? I love how bob templates lets you pip install requirements and then just edit the buildout.cfg file. Could it be possible to install 3.x sites and 4.x sites with pip ?