New post: Using jlink to cross-compile minimal JREs
https://jakewharton.com/using-jlink-to-cross-compile-minimal-jres/
I've been doing this inside Docker containers for a while to keep their size down, but recently needed it to target an embedded Linux ARM device with only 100MiB of storage.
@jw I tried that for some service we're deploying to kubernetes at work. It took far too much trial and error for me to feel safe that I didn't miss anything (to a point I ran into bugs of jlink in JDK16 or 17 can't remember exactly), and I decided it wasn't worth the effort. Yes, it reduces the attack surface due to less code, and there's faster download.. but do people really go the extra mile for Docker images?
I don't think you absolutely have to, but it takes some of my images from being 140MiB to 40MiB which is a nice reduction. The only problems I've really had are libraries which cause needless modules to be kept. But I suspect it varies based on the libraries you use and how much reflection/unsafe magic they're doing. I certainly have had more success with jlink than I've had with Graal native-image.
