Dockerでcentos:centos6イメージを起動して、docker execでopenssh-serverをインストール・起動し、sudoをインストール・設定して、sudo実行可能な一般ユーザーを作成して最後にSSHのコマンドを表示する

start-centos.sh

#! /bin/sh

: ${image=centos:centos6}
: ${name=centos-test}
: ${run_command=/sbin/init}
: ${user=${USER}}
: ${ssh_key=$HOME/.ssh/id_rsa.pub}

set -x

docker run -d --name ${name} ${image} ${run_command}
docker exec -ti ${name} yum install -y openssh-server
docker exec -ti ${name} service sshd start
docker exec -ti ${name} yum install -y sudo
docker exec -ti ${name} bash -c 'umask 226; cat > /etc/sudoers.d/local' << END_OF_SUDOERS
%wheel  ALL=(ALL) NOPASSWD: ALL
END_OF_SUDOERS
docker exec -ti ${name} adduser ${user}
docker exec -ti ${name} usermod -G adm,wheel ${user}
docker exec -ti ${name} sudo -u ${user} bash -c 'mkdir -m 700 ~/.ssh'
docker exec -ti ${name} sudo -u ${user} bash -c 'umask 066; cat > ~/.ssh/authorized_keys' < ${ssh_key}
docker exec -ti ${name} pkill cat
docker exec -ti ${name} passwd ${user}
## or use chpasswd:
##   bash -c 'echo "username:plainpassword" | chpasswd'
##   bash -c 'echo "username:encryptedpassword" | chpasswd -e'
## openssl can create encryptedpassword by:
##   echo "plainpassword" | openssl passwd -1 -stdin

set +x

ip=`docker inspect -f '{{.NetworkSettings.IPAddress}}' ${name}`

echo "Now you can login to container by following command:"
echo "  ssh -o \"UserKnownHostsFile /dev/null\" -o \"StrictHostKeyChecking no\" -i ${ssh_key%.pub} ${user}@${ip}"