I am writing a Dockerfile to customize the parrotsec/security container to better suit my preferences, and I’d want zsh as the default shell of root. I tried using
RUN chsh -s /usr/bin/zsh
as well as
RUN usermod --shell /usr/bin/zsh root
but after building the image and running it the shell for the root user remains bash.
>Solution :
I believe you’ll need to add an ENTRYPOINT to your Dockerfile. If you run a docker inspect <image> you’ll see an Entrypoint entry in the output.
See Docker Spawn a shell as a user instead of root which seems pretty closely related to your situation.