I'm very weak when it comes to stuff at this level but this sounds like it might be something I really want to know. If I want to run Python or Ruby, what is the practical downside to Alpine? Am I understanding correctly that Python or Ruby interpreters built to run on Alpine use musl instead of glibc, and that might have very noticeable performance impacts?
This thread is opening my eyes, I kind of assumed as long as I was running the right version of those interpreters, I was getting more or less the same thing. That feels like a very bad assumption now.
As always when it comes to performance, you should measure the difference yourself and see if it's a switch worth doing for your use case. "very noticeable performance impacts" depends so much on the context that it's hard to answer in a general way.
I was just a casual local user, and didn't have any production use of it. At the time, if my memory serves, images easily got into many GB locally. This was before Ubuntu and others had produced smaller official images of their own.
Footprint (ie. of the built container image which must be transferred back and forth to repos) and runtime performance are two different things you may care to optimize differently or not.
In terms of what? Performance? Musl is more correct. Most people aren't serving Google or Facebook levels of requests.
My only issue is with people choosing software purely based on performance.
That's really become a docker meme. Please be aware you're sacrificing performance due to not using glibc.