Changing the user's uid in a pre-build docker container (jenkins)

Question

I am new to docker, so if this is a fairly obvious process that I am missing, I do apologize for the dumb question up front.

I am setting up a continuous integration ser

Answer 1

Please take a look at the docker file I just uploaded: https://github.com/bdruemen/jenkins-docker-uid-from-volume/blob/master/Dockerfile . Here the UID is extracted from a mounted volume (host directory), with

stat -c '%u' 

Then the UID of the container user is changed to the same value with

usermod -u 

This has to be done as root, but then root privileges are dropped with

gosu  

Everything is done in the ENTRYPOINT, so the real UID is unknown until you run

docker run -d -v : ...

Note that after changing the UID, there might be some other files no longer accessible for the process in the container, so you might need a

chown -R  

before the gosu command.

You can also change the GID, see my answer here Jenkins in docker with access to host docker and maybe you want to change both to increase security.