Why isn't there a openjdk-8-jdk package on debian anymore?
Solution 1:
You are on Debian 10 (buster), but the link you showed is for Debian 9 (stretch).
OpenJDK is on version 11 for Buster and OpenJDK 8 is not available.
https://packages.debian.org/buster/openjdk-11-jdk
If you need this, use a docker image based on Stretch.
Solution 2:
Apparently Debian 10 alias Buster only provides openjdk 11 packages.
In my case this meant using debian 9 alias stretch instead. I must admit it wasn't very clever using latest as a version in the first place.
before:
FROM debian:latest
after:
FROM debian:stretch
Debian stretch is a LTS version supported until 06.2022