Dockerhub login works but docker login does not

Question

I am able to login to DockerHub, but from my linux machine if I run

docker login -u DOCKER_USER -p DOCKER_PASS

with the same credentials that allow me to login on dockerhub, I get

Error response from daemon: Get "https://registry-1.docker.io/v2/": unauthorized: incorrect username or password

My passworkd contains an exclamation mark that creates me some issues, but enclosing it in single quotes should work, right? Like

docker login -u DOCKER_USER -p 'my!pass'

What could be the problem? Should I set the server argument of docker login? If yes, how do I know which server ?

Answer 1

Very simple solution: I was using the username with some uppercase letters, which were working when logging in in the DockerHub website but not in the docker login command. As usernames are always lowercase, simply writing the username in lowercase letters worked.

I assume the DockerHub website does this conversion automatically, so it was transparent to me