Setting up an SSH server on @dotcloud docker CentOS image

setup.sh

# Install OpenSSH server and SSH client
yum install -y openssh-server
yum install -y openssh-clients

# Install passwd
yum install -y passwd

# Set root password
passwd
# TODO: Enter new root password
# TODO: Repeat new root password

# Test ssh
ssh root@localhost

# Enter root password when prompted
# ERROR: Connection to localhost closed.
# ERROR: Exit status 254

to fix, add to your docker file:

RUN sed -ri 's/UsePAM yes/#UsePAM yes/g' /etc/ssh/sshd_config
RUN sed -ri 's/#UsePAM no/UsePAM no/g' /etc/ssh/sshd_config

I also got "Exit status 254" when connecting to a Docker container of stackbrew/ubuntu:13.10 running openssh-server.

Changing UsePAM yes to UsePAM no inside /etc/ssh/sshd_config solved it. Dunno what that setting does though.

I encountered the same problem.

Check out this: http://docs.docker.io/en/latest/examples/running_ssh_service/

At the bottom, it states the following:

    For Ubuntu 13.10 using stackbrew/ubuntu, you may need do these additional steps:

    change /etc/pam.d/sshd, pam_loginuid line ‘required’ to ‘optional’
    echo LANG=”en_US.UTF-8” > /etc/default/locale

Changing UsePAM yes to UsePAM no inside /etc/ssh/sshd_config solved it.

Solved it for us too. Thanks.

You can check if it's a PAM issue by starting a container and overriding the CMD to run sshd in the foreground...

$ docker run -i -t -p 127.0.0.1::22 our-base-ubuntu:13.10 /usr/sbin/sshd -D -e
Server listening on 0.0.0.0 port 22.
Server listening on :: port 22.
Accepted password for fred from 192.168.42.1 port 40892 ssh2
PAM: pam_open_session(): Cannot make/remove an entry for the specified session
Received disconnect from 192.168.42.1: 11: disconnected by user

@pungoyal Thank you! It helped me too!

RUN sed -ri 's/UsePAM yes/#UsePAM yes/g' /etc/ssh/sshd_config
RUN sed -ri 's/#UsePAM no/UsePAM no/g' /etc/ssh/sshd_config

Thanks for the tip on UsePAM. Works great! Been looking for a solution for like an hour. 👍

Still, I wonder why it does that.

I guess this PAM setting is not needed since docker 1.0.0

PAM setting is not needed +1

PAM setting is still needed (Docker 1.4, phusion/baseimage:latest). -1

For automating the passwd part

( sleep .1 ; printf "%s\n" "password" "password" ) | passwd

Then password could be easily editable through other means using Jinja during deployment or something...