In order to successfully clone a private repository into an Alpine-based docker, I needed to run the following command:
ssh-keyscan github.com >> ~/.ssh/known_hosts
.
But since ssh-keyscan isn't part of Alpine linux (by default), I have to install it first with apk. The problem is: I dont know how - and I can't find it anywhere on Google.
This took way too long to find out as its not documented anywhere:
apk update && apk add openssh
or alternatively:
apk add -qU openssh