SSHD Dockerfile

sshd.Dockerfile

FROM alpine:edge
RUN apk add --no-cache openssh sudo
RUN ssh-keygen -t ed25519 -f /etc/ssh/ssh_host_ed25519_key -N ''
RUN adduser -D -s /bin/ash -u 1000 system && \
  echo "system ALL=(ALL:ALL) NOPASSWD:ALL" > /etc/sudoers && \
  sed -i -r 's/^system:!:/system:x:/' /etc/shadow && \
  echo "Hello Developers!" > /etc/motd
RUN sed -i \
  -e 's/^AllowTcpForwarding.*$/AllowTcpForwarding yes/' \
  -e 's/^.*#PermitRootLogin.*$/PermitRootLogin no/' \
  -e 's/^.*#PermitEmptyPasswords.*$/PermitEmptyPasswords no/' \
  -e 's/^.*#TCPKeepAlive.*$/TCPKeepAlive yes/' \
  -e 's/^.*#ClientAliveInterval.*$/ClientAliveInterval 300/' \
  -e 's/^.*#ClientAliveCountMax.*$/ClientAliveCountMax 0/' \
  -e 's/^.*#PasswordAuthentication.*$/PasswordAuthentication no/' \
  -e 's/^.*#ChallengeResponseAuthentication.*$/ChallengeResponseAuthentication no/' \
  -e 's@^.*AuthorizedKeysFile.*$@AuthorizedKeysFile .ssh/authorized_keys /etc/ssh/authorized_keys@' \
  /etc/ssh/sshd_config && \
  mkdir -p /run/sshd
CMD ["/usr/sbin/sshd", "-D", "-e"]