Docker で SSH 接続可能なコンテナ (CentOS) を作成する ref: http://qiita.com/comutt/items/1251cc19885947cd6d3d

file0.sh

alias ssh-ignorekey='ssh -oUserKnownHostsFile=/dev/null -oStrictHostKeyChecking=no'

file1.txt

FROM centos

RUN yum -y install initscripts MAKEDEV

RUN yum check

RUN yum -y update

RUN yum -y install openssh-server

# 空パスワードの場合は以下をコメントアウト
# RUN sed -ri 's/^#PermitEmptyPasswords no/PermitEmptyPasswords yes/' /etc/ssh/sshd_config

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

RUN /etc/init.d/sshd start

# 空パスワードの場合は以下をコメントアウト
# RUN passwd -d root

# 任意のパスワードの場合は以下をコメントアウト & パスワードを書き換える
# RUN echo 'root:root' | chpasswd

EXPOSE 22

CMD /sbin/init

file2.sh

CONTAINER_ID=$(docker run -P -d ssh-enabled) && SSH_PORT=$(docker port $CONTAINER_ID 22 | cut -d: -f2) && SSH_HOST=$(docker port $CONTAINER_ID 22 | cut -d: -f1);

file3.sh

ssh-ignorekey -p $SSH_PORT root@$SSH_HOST

file4.txt

FROM centos

RUN yum -y install initscripts MAKEDEV

RUN yum check

RUN yum -y update

RUN yum -y install openssh-server

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

RUN /etc/init.d/sshd start

RUN sed -ri 's/^(root):[^:]*:(.*)$/\1:*:\2/' /etc/shadow

RUN ssh-keygen -f ~root/.ssh/id_rsa -t rsa -b 2048 -N ''
RUN cp ~root/.ssh/id_rsa.pub ~root/.ssh/authorized_keys
RUN chmod 0600 ~root/.ssh/authorized_keys

EXPOSE 22

CMD /sbin/init

file5.sh

CONTAINER_ID=$(docker run -P -d ssh-enabled) && SSH_PORT=$(docker port $CONTAINER_ID 22 | cut -d: -f2) && SSH_HOST=$(docker port $CONTAINER_ID 22 | cut -d: -f1);

file6.sh

docker cp $CONTAINER_ID:/root/.ssh/id_rsa $CONTAINER_ID

file7.sh

ssh-ignorekey -i $CONTAINER_ID/id_rsa -p $SSH_PORT root@$SSH_HOST