Yes, it should be possible, although you would need to setup your Chef 12 server and create an org and make sure you then uploaded the data to that org on the Chef 12 server, since Chef 12 make multiple orgs open source, when it had not been before. You’d want to do try this on a test system first, as there will likely be gotchas in there on how you need to change the data to make it all migrate nicely.
Otherwise going from 10 to latest 11 to 12 will handle all of that for you. Here are the docs on upgrading from open source 11 to 12: https://docs.chef.io/release/server_12-4/upgrade_server.html#from-chef-server-osc
The code that is doing the 11 to 12 upgrade lives here: https://github.com/chef/chef-server/blob/master/omnibus/files/private-chef-ctl-commands/open_source_chef12_upgrade.rb
That will give you an idea of what is happening under the hood (like the 10 to 11 upgrade, it’s a download, transform, and upload process) and might help you determine what you need to do to jump from 10 to 12.
- Mark Mzyk
Chef Engineering Manager