#!/bin/bash
# Version: 0.3.0-rsync
# Copyright (c) 2005-2022:
#   Darren 'Tadgy' Austin <darren (at) afterdark.org.uk>
# Licensed under the terms of the GNU General Public License version 3.

# shellcheck disable=SC2016,SC2034

RSYNC_EXEC="/usr/bin/rsync"
RSYNC_ARGS=('--daemon' '${RSYNC_CONF:---config=/etc/rsyncd/rsyncd.conf}')
RSYNC_PIDFILE="/run/rsyncd.pid"
DAEMON_EXEC="/usr/bin/daemon"
DAEMON_ARGS=('-N' '-n' "lumberjack-${0##*rc.}" '-r' '-a' '60' '-A' '5' '-L' '1800' '-M' '3' '-l' 'daemon.err' '-b' 'daemon.debug' '-o' 'daemon.info' '--')
LUMBERJACK_EXEC="/opt/bin/lumberjack"
LUMBERJACK_ARGS=('-u' '${LUMBERJACK_RUNUSER:-logger}' '-z' '-r' '-i' '${LUMBERJACK_SOCK:-/run/rsyncd-log.sock}' '-o' '${LUMBERJACK_RUNUSER:-logger}:mirror' '-mp' '006' '-l' 'logs/rsyncd-transfers.log' '${LUMBERJACK_BASEDIR:-/data/sites/slackware.uk}' 'logs/%Y/%m/rsyncd-transfers.log')
LUMBERJACK_RUNUSER="logger"
LUMBERJACK_SOCK="/run/rsyncd-log.sock"
LUMBERJACK_BASEDIR="/data/sites/slackware.uk"

# Allow configuration in /etc/default to override.
# Additional available variables:
#   RSYNC_ENVIRONMENT=()	# Extra environment passed to $RSYNC_EXEC.  Must be an array.
#   RSYNC_CONF=""		# Path to the config file for RSYNC_EXEC.  Default: /etc/rsyncd/rsyncd.conf.
#   DAEMON_ENVIRONMENT=()	# Extra environment passed to $DAEMON_EXEC.  Must be an array.
#   LUMBERJACK_RUNUSER=""	# Username to run lumberjack as.  Default: logger.
#   LUMBERJACK_SOCK=""		# Location of the socket for lumberjack to read data.  Default: /run/rsyncd-log.sock.
#   LUMBERJACK_BASEDIR=""	# The base directory where lumberjack should write logs.  Default: /data/sites/slackware.uk.
#   SLAY_DELAY=""		# Delay between the SIGTERM and SIGKILL on a 'stop'.  Default: 2s.
#   RESTART_DELAY=""		# Delay between stopping and starting on a 'restart'.  Default: 2s.
# shellcheck disable=SC1090
[[ -e "/etc/default/${0##*rc.}" ]] && { source "/etc/default/${0##*rc.}" || return 1 2>/dev/null || exit 1; }

# Now all possible variable changes are complete, expand out the embedded variables.
eval "$(declare -p RSYNC_ARGS | sed -re 's/\\\$/$/g')"
eval "$(declare -p LUMBERJACK_ARGS | sed -re 's/\\\$/$/g')"

error() {
  printf "%s: %s\\n" "${BASH_SOURCE[0]##*/}" "$*" >&2
}

checkconfigured() {
  # This function can be used to perform any pre-start tests; hopfully to insure the daemon
  # can start correctly, before actually trying to start it.  A return value of 0 means the
  # tests were passed and the daemon should be started.  Any other value prevents the
  # daemon from being started, and an error message will be emitted.
  id "${LUMBERJACK_RUNUSER:-logger}" >/dev/null 2>&1 || return 1
  [[ ! -e "${LUMBERJACK_BASEDIR:-/data/sites/slackware.uk}" ]] && return 1
  [[ ! -d "${LUMBERJACK_BASEDIR:-/data/sites/slackware.uk}" ]] && return 1
  [[ ! -e "${RSYNC_CONF:-/etc/rsyncd/rsyncd.conf}" ]] && return 1
  return 0
}

checkstatus() {
  # shellcheck disable=SC2155
  local RET=0 RUNPIDS="$({ pgrep -f "$RSYNC_EXEC"; pgrep -F "$RSYNC_PIDFILE" 2>/dev/null; } | sort -u )"
  if "$DAEMON_EXEC" --running -n "lumberjack-${0##*rc.}"; then
    printf "%s: %s: %s\\n" "${BASH_SOURCE[0]##*/}" "${LUMBERJACK_EXEC##*/}" "running"
  else
    printf "%s: %s: %s\\n" "${BASH_SOURCE[0]##*/}" "${LUMBERJACK_EXEC##*/}" "stopped"
    RET=1
  fi
  if [[ -n "$RUNPIDS" ]]; then
    printf "%s: %s: %s" "${BASH_SOURCE[0]##*/}" "${RSYNC_EXEC##*/}" "running"
    if [[ -n "$RSYNC_PIDFILE" ]]; then
      if [[ ! -e "$RSYNC_PIDFILE" ]]; then
        printf "%s" ", but .pid file does not exist"
      elif ! grep "\<$(<"$RSYNC_PIDFILE")\>" <<<"$RUNPIDS" >/dev/null 2>&1; then
        printf "%s" ", but .pid file is stale"
      fi
    fi
    printf "\\n"
  else
    printf "%s: %s: %s\\n" "${BASH_SOURCE[0]##*/}" "${RSYNC_EXEC##*/}" "stopped"
    RET=$(( RET + 2))
  fi
  return $RET
}

startdaemon() {
  checkconfigured || {
    error "${RSYNC_EXEC##*/}: not started - pre-start checks failed"
    return 2
  }
  # shellcheck disable=SC2048,SC2086
  ${DAEMON_ENVIRONMENT:+declare ${DAEMON_ENVIRONMENT[*]};} "$DAEMON_EXEC" ${DAEMON_ARGS[*]} "$LUMBERJACK_EXEC" ${LUMBERJACK_ARGS[*]}
  # shellcheck disable=SC2181
  (( $? != 0 )) && {
    error "error starting '${DAEMON_EXEC##*/}'"
    return 2
  }
  # shellcheck disable=SC2048,SC2086
  ${RSYNC_ENVIRONMENT:+declare ${RSYNC_ENVIRONMENT[*]};} "$RSYNC_EXEC" ${RSYNC_ARGS[*]}
  # shellcheck disable=SC2181
  if (( $? != 0 )); then
    error "error starting '${RSYNC_EXEC##*/}'"
    return 2
  else
    return 0
  fi
}

stopdaemon() {
  kill -TERM "$(pgrep -f "$RSYNC_EXEC" | tr $'\n' ' ')" >/dev/null 2>&1
  [[ -e "$RSYNC_PIDFILE" ]] && {
    sleep 0.5
    kill -TERM "$(<"$RSYNC_PIDFILE")" >/dev/null 2>&1
  }
  sleep "${SLAY_DELAY:-2}"
  checkstatus >/dev/null && {
    error "${RSYNC_EXEC##*/}: failed to stop gracefully - slaying"
    kill -KILL "$({ cat "$RSYNC_PIDFILE"; pgrep -f "$RSYNC_EXEC"; } 2>/dev/null | sort -u | tr $'\n' ' ')" >/dev/null 2>&1
  }
  sleep 0.5
  "$DAEMON_EXEC" -n "lumberjack-${0##*rc.}" --stop 2>/dev/null
  sleep "${SLAY_DELAY:-2}"
  checkstatus >/dev/null && {
    error "${DAEMON_EXEC##*/}: failed to stop gracefully - slaying"
    "$DAEMON_EXEC" -n "lumberjack-${0##*rc.}" --signal=kill 2>/dev/null
  }
  return 0
}

for EXEC in "$RSYNC_EXEC" "$DAEMON_EXEC" "$LUMBERJACK_EXEC"; do
  [[ ! -e "$EXEC" ]] && {
    error "$EXEC: not found"
    return 1 2>/dev/null || exit 1
  }
  [[ ! -x "$EXEC" ]] && {
    error "$EXEC: not executable"
    return 1 2>/dev/null || exit 1
  }
done

case "$1" in
  'start')
    checkstatus >/dev/null
    ERR=$?
    if (( ERR == 3 )); then
      startdaemon
      RET=$?
    elif (( ERR == 2 )); then
      error "${DAEMON_EXEC##*/}: already running"
      error "${RSYNC_EXEC##*/}: stopped"
      printf "  %s\\n" "Try: ${BASH_SOURCE[0]} restart" >&2
      RET=1
    elif (( ERR == 1 )); then
      error "${DAEMON_EXEC##*/}: stopped"
      error "${RSYNC_EXEC##*/}: already running"
      printf "  %s\\n" "Try: ${BASH_SOURCE[0]} restart" >&2
      RET=1
    else
      error "${DAEMON_EXEC##*/}: already running"
      error "${RSYNC_EXEC##*/}: already running"
      printf "  %s\\n" "Try: ${BASH_SOURCE[0]} status" >&2
      RET=1
    fi
    ;;
  'stop')
    checkstatus >/dev/null
    if (( $? == 3 )); then
      error "${DAEMON_EXEC##*/}: not running"
      error "${RSYNC_EXEC##*/}: not running"
      printf "  %s\\n" "Try: ${BASH_SOURCE[0]} status" >&2
      RET=1
    else
      stopdaemon
      RET=$?
    fi
    ;;
  'restart')
    checkstatus >/dev/null
    (( $? != 3 )) && {
      stopdaemon >/dev/null 2>&1
      sleep "${RESTART_DELAY:-2}"
    }
    startdaemon
    RET=$?
    ;;
  'status')
    checkstatus
    RET=$?
    ;;
  *)
    printf "%s\\n" "Usage: ${BASH_SOURCE[0]} <start|stop|restart|status>" >&2
    RET=1
    ;;
esac

return $RET 2>/dev/null || exit $RET