I took the semaphore docker image and via docker file I installed an ssh server. Now I’m faced with a problem:

FROM semaphoreui/semaphore:latest

USER root

RUN apk update && 
    apk add --no-cache openssh openrc

RUN echo "PermitRootLogin yes" >> /etc/ssh/sshd_config && 
    echo "PasswordAuthentication yes" >> /etc/ssh/sshd_config && 
    echo "semaphore:password" | chpasswd

RUN mkdir -p /var/run/sshd

RUN cd /etc/ssh && ssh-keygen -A

EXPOSE 22

USER semaphore

I make the image.

docker build . -t semaphore:ssh

When I launch the container I have to start the ssh server as root user, but I want the container to be started with semaphore user, so I am forced to launch the conatiner as a normal user but then to give an additional command via docker exec which starts the ssh server :

docker run --name semaphore_instance -d semaphore:ssh

docker exec -u0 semaphore_instance /usr/sbin/sshd -D &

Is there a way to avoid this and launching the service with no root user?