git.Dockerfile

FROM debian:12-slim

ENV DEBIAN_FRONTEND=noninteractive

RUN adduser git --home /srv/git && \
  chown -R git:git /srv/git

RUN apt-get update && \
  apt-get install --yes --no-install-recommends --no-install-suggests git openssh-server && \
  apt-get clean && \
  rm -rf /var/lib/apt/lists/* && \
  sed -i 's/#AuthorizedKeysFile.*/AuthorizedKeysFile \/etc\/ssh\/keys\/%u\/authorized_keys/' /etc/ssh/sshd_config && \
  mkdir /run/sshd

ADD id_ed25519.pub /etc/ssh/keys/git/authorized_keys
ADD ssh_host_* /etc/ssh

EXPOSE 22
VOLUME ["/srv/git"]
CMD ["/usr/sbin/sshd", "-D", "-e"]