entrypoint.sh

#!/bin/bash

: "${HOST_KEYS_SRC_DIR:="/notexisting"}"

set -eux -o pipefail

case "${RSYNCD_DAEMON:-rsyncd}" in
    'rsyncd')
      # We do not want expansion for envsubst argument
      # shellcheck disable=SC2016
      envsubst '$RSYNCD_PORT $USER_ETC_DIR $USER_RUN_DIR'< "${USER_ETC_DIR}"/rsyncd.conf.orig > "${USER_ETC_DIR}"/rsyncd.conf
      cat "${USER_ETC_DIR}"/rsyncd.conf
      # Start rsyncd daemon
      exec /usr/bin/rsync --no-detach --daemon --config "${USER_ETC_DIR}"/rsyncd.conf;;
    'sshd')
      # We do not want expansion for envsubst argument
      # shellcheck disable=SC2016
      envsubst '$SSHD_PORT $SSHD_LOG_LEVEL $USER_ETC_DIR $USER_RUN_DIR $HOST_KEYS_DIR'< "${USER_ETC_DIR}"/sshd_config.orig > "${USER_ETC_DIR}"/sshd_config

      # Generate hostkeys if absent
      if [ -d "${HOST_KEYS_SRC_DIR}" ]
      then
        rsync -av "${HOST_KEYS_SRC_DIR}"/ssh_host* "${HOST_KEYS_DIR}"/
      fi

      test -f "${HOST_KEYS_DIR}"/ssh_host_dsa_key || ssh-keygen -q -N "" -t dsa -f "${HOST_KEYS_DIR}"/ssh_host_dsa_key
      test -f "${HOST_KEYS_DIR}"/ssh_host_rsa_key || ssh-keygen -q -N "" -t rsa -b 4096 -f "${HOST_KEYS_DIR}"/ssh_host_rsa_key
      test -f "${HOST_KEYS_DIR}"/ssh_host_ecdsa_key || ssh-keygen -q -N "" -t ecdsa -f "${HOST_KEYS_DIR}"/ssh_host_ecdsa_key
      test -f "${HOST_KEYS_DIR}"/ssh_host_ed25519_key || ssh-keygen -q -N "" -t ed25519 -f "${HOST_KEYS_DIR}"/ssh_host_ed25519_key

      # Load public key if provided
      if [[ "${SSHD_PUBLIC_KEY:-'defaultNoKey'}" == ssh-* ]]; then
        mkdir -p "${HOME}/.ssh"
        chmod 0700 "${HOME}/.ssh"
        ssh_rsync_key="command=\"/ssh-rsync-wrapper.sh\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty ${SSHD_PUBLIC_KEY}"
        echo "${ssh_rsync_key}" > "${HOME}/.ssh/authorized_keys"
        chmod 0600 "${HOME}/.ssh/authorized_keys"
      fi

      # Start SSHD daemon
      exec /usr/sbin/sshd -D -f "${USER_ETC_DIR}"/sshd_config -e;;
    *)
      echo "ERROR: 'RSYNCD_DAEMON' can only take one of the following values: 'rsyncd' (default), 'sshd";
      exit 1;;
esac