Issue
This might be a stupid question, but I am going to ask it anyways...
I would like to be a superuser in the container if I run docker exec -it <container> /bin/bash.
<container> is a container that is built on a fedora-base-image which seems to assign me a user with non-sudo capabilities.
Question: Is there a way to still become superuser in my new image, if it was based on such an image?
Why do I want this? I would like to run gdb attach in this container, which gives me ptrace: Operation not permitted. I already tried to do docker run --cap-add=SYS_PTRACE --security-opt seccomp=unconfined --security-opt apparmor=unconfined (compare here), which did not work. So my next guess would be to try this as super-user, as recommended in the same post.
Solution
with docker run you can pass the user flag.
-u, --user string Username or UID (format: <name|uid>[:<group|gid>])
I believe the UID of root should be 0, so I think any of -u root -u 0 -u root:root should work?
If you're building a Dockerfile you can also add USER root to your dockerfile to switch users.
Answered By - maxm Answer Checked By - Willingham (WPSolving Volunteer)