This says it's not meant for production use.

Does anyone know of something that is meant for production use for generating in-house certificate authorities and signing certificates?

I've used scripts I've written myself that run OpenSSL commands. They get the job done, but they're not the kind of thing that fits all use cases, and they're not user-friendly.

I've tried EasyRSA which is not particularly easy either. It requires some unexpected use of environment variables, and I didn't find the documentation very clear either.

cfssl is what I use, usually a root + intermedia ca, and leaf certs, works really well with cert manager in kubernetes.

https://github.com/cloudflare/cfssl