Jenkins always logins to Docker slaves as root

[Viliam Rockai]

Hey all,

After an upgrade (2.60.1 -> 2.73.2) and after updating all plugins to recent versions (Docker plugin 0.18, SSH slaves plugin 1.21) my docker slaves stopped working. I've managed to figure out most of the configuration changes needed but I still got issue. Jenkins always logins to the slave as "root", instead of the "jenkins" user who does have credentials provided (https://snag.gy/gk3xJd.jpg). I'm using slaves based on the evarga/jenkins-slave image.

Do I need to setup keys now or is there any way to make the old good "login way" work again? If I need to setup keys, is there any good tutorial for that?

Thanks!

Viliam