Dockerfile

FROM centos:6
MAINTAINER Oskars G.

RUN yum -y install openssh-server
RUN ssh-keygen -q -N "" -t dsa -f /etc/ssh/ssh_host_dsa_key
RUN ssh-keygen -q -N "" -t rsa -f /etc/ssh/ssh_host_rsa_key
RUN ssh-keygen -q -N "" -t ecdsa -f /etc/ssh/ssh_host_ecdsa_key
RUN sed -i "s/#UsePrivilegeSeparation.*/UsePrivilegeSeparation no/g" /etc/ssh/sshd_config
RUN sed -i 's/#UsePAM no/UsePAM no/g' /etc/ssh/sshd_config

# create user with pass 'user'
RUN adduser user -p '$6$Yu.kO8se$BKxhp56L/gXYcWMNCsQT0sxeqnTYCzyuWcZfcfRxgf6Cad21yrebI6HWhon2u0VerklBg2o8HhG8yBbl0OBim/' 

# add user to sudoers
RUN yum install sudo -y
RUN echo '%user ALL=(ALL) NOPASSWD:ALL' >> /etc/sudoers

EXPOSE 22
CMD ["/usr/sbin/sshd", "-D"]