Created Init-Container that pulls pubkeys from git, creates authorized_keys, ssh-host-keys and backup-repo folders

init/entrypoint.sh

@@ -0,0 +1,107 @@
+#!/bin/bash
+# Init-Start Script for docker-borgserver
+# Will pull ssh-keys from git specified via KEY_GIT_URL and KEY_GIT_BRANCH [default: master]
+# and merge them into a single [openssh] authorized_keys file.
+PUID=${PUID:-1000}
+PGID=${PGID:-1000}
+
+usermod -o -u "$PUID" borg &>/dev/null
+groupmod -o -g "$PGID" borg &>/dev/null
+
+# FIXME: Is this changeable? guess it should be.. should move it to some kind of
+# build-env file
+BORG_DATA_DIR=${BORG_DATA_DIR:-/backup}
+
+BORG_CMD='cd ${BORG_DATA_DIR}/${client_name}; borg serve --restrict-to-path ${BORG_DATA_DIR}/${client_name} ${BORG_SERVE_ARGS}'
+KEY_GIT_BRANCH=${KEY_GIT_BRANCH:-master}
+
+# This is the path where the final authorized_keys will be written:
+AUTHORIZED_KEYS_PATH=${AUTHORIZED_KEYS_PATH:-/home/borg/.ssh/authorized_keys}
+
+# This will only contain host-keys now
+SSH_KEY_DIR=${SSH_KEY_DIR:-/sshkeys}
+
+# This is no volume anymore, only temporary during init
+GIT_KEY_DIR=/tmp/gitkeys
+echo "########################################################"
+echo " * Docker BorgServer | Git Init-Container *"
+echo " * $(id)"
+
+if [ ! -z "${KEY_GIT_URL}" ] ; then
+  # FIXME: Should the container die here, in case of error?
+  # To workaround the limitations of docker-compose we could just loop here like.. forever
+
+  # INFO: simle git clone would be enouth, but you can also use a volume for SSH_KEY_DIR if you like
+  echo " * Cloning '${KEY_GIT_URL}' into '${GIT_KEY_DIR}/clients'"
+  if [ ! -d "${GIT_KEY_DIR}/clients/.git" ] ; then
+    git clone -b ${KEY_GIT_BRANCH} --depth=1 "${KEY_GIT_URL}" "${GIT_KEY_DIR}/clients"
+  else
+    git -C "${GIT_KEY_DIR}/clients" pull
+  fi
+else
+  echo " ! FATAL ERROR: KEY_GIT_URL is not set! Can't continue."
+  exit 1
+fi
+
+if [ "$(find ${GIT_KEY_DIR}/clients ! -regex '.*/\..*' -a -type f | wc -l)" == "0" ] ; then
+  echo " ! FATAL ERROR: No SSH-Pubkey file found in ${GIT_KEY_DIR}. Can't continue."
+  exit 2
+fi
+
+# Create SSH-Host-Keys on persistent storage, if not exist
+# This also means that `${SSH_KEY_DIR}` has to be a shared volume
+echo " * Checking / Preparing SSH Host-Keys..."
+for keytype in ed25519 rsa ; do
+  if [ ! -f "${SSH_KEY_DIR}/ssh_host_${keytype}_key" ] ; then
+    echo "  ** Creating SSH Hostkey [${keytype}]..."
+    ssh-keygen -q -f "${SSH_KEY_DIR}/ssh_host_${keytype}_key" -N '' -t ${keytype}
+  fi
+done
+
+echo "########################################################"
+echo " * Starting SSH-Key import..."
+
+# Add every key to borg-users authorized_keys
+# FIXME: mkdir of filestructure must still be done by server-container
+# since we shouldn't have access to the backup-data volume in init
+rm -f ${AUTHORIZED_KEYS_PATH} &>/dev/null
+for keyfile in $(find "${GIT_KEY_DIR}" ! -regex '.*/\..*' -a -type f); do
+  client_name=$(basename ${keyfile})
+
+  # check if file is a valid openssh public key
+  if ! ssh-keygen -lf $keyfile &>/dev/null ; then
+    echo " ! WARNING: '$keyfile' is not a valid [open]ssh-public-key. Will continue anyway."
+    continue
+  fi
+
+  # If client is $BORG_ADMIN unset $client_name, so path restriction equals $BORG_DATA_DIR
+  # Otherwise add --append-only, if enabled
+  borg_cmd=${BORG_CMD}
+  if [ "${client_name}" == "${BORG_ADMIN}" ] ; then
+    echo "   ** Client '${client_name}' is BORG_ADMIN! **"
+    unset client_name
+  elif [ "${BORG_APPEND_ONLY}" == "yes" ] ; then
+    borg_cmd="${BORG_CMD} --append-only"
+  fi
+
+  echo -n "command=\"$(eval echo -n \"${borg_cmd}\")\" " >> ${AUTHORIZED_KEYS_PATH}
+  cat ${keyfile} >> ${AUTHORIZED_KEYS_PATH}
+done
+
+# This will also fail if there wasn't a single valid pubkey found
+echo " * Validating structure of generated ${AUTHORIZED_KEYS_PATH}..."
+if ! ssh-keygen -lf ${AUTHORIZED_KEYS_PATH} >/dev/null ; then
+  echo " ! FATAL ERROR: ${AUTHORIZED_KEYS_PATH} is no valid authorized_keys file. Can't continue."
+  exit 3
+fi
+
+echo " * Correcting Permissions..."
+chown borg:borg ${AUTHORIZED_KEYS_PATH}
+chown -R borg:borg ${SSH_KEY_DIR}/*
+chown borg:borg ${BORG_DATA_DIR}
+chmod 600 ${AUTHORIZED_KEYS_PATH}
+
+echo "########################################################"
+echo " * Init done! Ready to fire up your borgserver!"
+
+exit 0