Okay so we needed a specific version of Ruby to get old gems and code compiling at a base system level. 1.9.3 something or other. But we had users that needed specific ruby versions, like 2.3.0 so their code could compile. It’s a weird layering, but we needed it. So begins the balance of multiple ruby versions.
How did we accomplish this dance?
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Used
ruby-installand set the base system to1.9.3ruby version. Installed the specific (old) gems. - 
    
Installed rbenv and set the local ruby version to whatever on the user path that needed it (
/home/user/). Reinstalledbundle, as a copy had been installed in the system level so we needed bundle for that particular version of ruby using rbenv. - 
    
Prefixed commands that used bundle/ruby with
rbenv execto specify to use rbenv’s ruby version instead of default system. 
That is the gist of it. Performed through packer and Chef to create a server that has this ruby versioning set up. It works.