Bug#857322: dnscrypt-proxy: initscript with multi-resolver support

[harald]

Dear Eric Dorland,

please find attached a prelimiary version of an initscript with multiple
resolver support. While it is still not perfect (no check for "Daemonize
no" in default config file, no check for config file being included by
other config files) it is already running in production use and doesn't
seem to create problems. If you would be willing to include it into
dnscrypt-proxy I would do the support for it. If somebody wants to test
it:

change 
Daemonize no
to
Daemonize yes

and add
User _dnscrypt-proxy

it the default config file

Kind regards
Harald Jenny

#!/bin/sh -e

### BEGIN INIT INFO
# Provides:          dnscrypt-proxy
# Required-Start:    $remote_fs
# Required-Stop:     $remote_fs
# Should-Start:      $network $syslog
# Should-Stop:       $network $syslog
# Default-Start:     2 3 4 5
# Default-Stop:      0 1 6
# Short-Description: Start and stop dnscrypt-proxy
# Description:       dnscrypt-proxy is Domain Name resolver with extra security
#        features and enhanced privacy.
### END INIT INFO

PATH=/sbin:/bin:/usr/sbin:/usr/bin

. /lib/lsb/init-functions

DNSCRYPT_PROXY_BIN=/usr/sbin/dnscrypt-proxy
DNSCRYPT_PROXY_CONFDIR=/etc/dnscrypt-proxy
DNSCRYPT_PROXY_HOME=/run/dnscrypt-proxy

# Exit if the package is not installed
[ -x "${DNSCRYPT_PROXY_BIN}" ] || exit 0

get_config () {
  if [ -e ${DNSCRYPT_PROXY_CONFDIR}/dnscrypt-proxy.conf ]; then
    if [ $(find ${DNSCRYPT_PROXY_CONFDIR} -maxdepth 1 -type f \
      -a -name "dnscrypt-proxy*.conf" \
      -a ! -name "dnscrypt-proxy-common.conf" \
      | wc -l) -gt 1 ]; then
        log_warning_msg "${DNSCRYPT_PROXY_CONFDIR}/dnscrypt-proxy.conf found, 
using this as config file."
        log_warning_msg "If you want multiple instances of dnscrypt-proxy then 
please rename"
        log_warning_msg "dnscrypt-proxy.conf permanently by using the following 
command:"
        log_warning_msg "dpkg-divert --local --divert FILENAME_OF_YOUR_CHOICE 
\\"
        log_warning_msg "--rename ${DNSCRYPT_PROXY_CONFDIR}/dnscrypt-proxy.conf"
    fi
    DNSCRYPT_PROXY_CONFS=${DNSCRYPT_PROXY_CONFDIR}/dnscrypt-proxy.conf
  else
    if [ -z "$2" ]; then
      DNSCRYPT_PROXY_CONFS=$(find ${DNSCRYPT_PROXY_CONFDIR} -maxdepth 1 -type f 
\
        -a -name "dnscrypt-proxy*.conf" \
        -a ! -name "dnscrypt-proxy-common.conf" | sort)
    else
      while shift ; do
        [ -z "$1" ] && break
        DNSCRYPT_PROXY_CONFS="${DNSCRYPT_PROXY_CONFS} 
${DNSCRYPT_PROXY_CONFDIR}/dnscrypt-proxy-$1.conf"
      done
    fi
  fi
}

start_instance () {
  if [ -e ${DNSCRYPT_PROXY_CONF} ]; then
    DNSCRYPT_PROXY_INSTANCE=$(basename ${DNSCRYPT_PROXY_CONF} | sed 
's/.conf$//')
    DNSCRYPT_PROXY_PIDFILE=$(grep "^PidFile" ${DNSCRYPT_PROXY_CONF} | awk 
'{print $2}')

    log_daemon_msg "Starting dnscrypt proxy service..." 
${DNSCRYPT_PROXY_INSTANCE}

    if start_daemon -p "${DNSCRYPT_PROXY_PIDFILE}" ${DNSCRYPT_PROXY_BIN} \
      ${DNSCRYPT_PROXY_CONF} 2>/dev/null; then
      if [ -x /sbin/resolvconf ]; then
        grep "^LocalAddress" ${DNSCRYPT_PROXY_CONF} \
          | awk '{print "nameserver "$2}' \
          | cut -d ':' -f 1 \
          | /sbin/resolvconf -a lo.${DNSCRYPT_PROXY_INSTANCE}
      fi
        log_success_msg
    else
      EXIT_STATUS=$?
      log_failure_msg
    fi
  else
    log_failure_msg "${DNSCRYPT_PROXY_CONF} not found" && EXIT_STATUS=3
  fi
}

stop_instance () {
  if [ -e ${DNSCRYPT_PROXY_CONF} ]; then
    DNSCRYPT_PROXY_INSTANCE=$(basename ${DNSCRYPT_PROXY_CONF} | sed 
's/.conf$//')
    DNSCRYPT_PROXY_PIDFILE=$(grep "^PidFile" ${DNSCRYPT_PROXY_CONF} | awk 
'{print $2}')

    log_daemon_msg "Stopping dnscrypt proxy service..." 
${DNSCRYPT_PROXY_INSTANCE}

    if [ -x /sbin/resolvconf ]; then
      /sbin/resolvconf -d lo.${DNSCRYPT_PROXY_INSTANCE}
    fi

    if killproc -p "${DNSCRYPT_PROXY_PIDFILE}" ${DNSCRYPT_PROXY_BIN}; then
      log_success_msg
    else
      echo $?
      EXIT_STATUS=$?
      log_failure_msg
    fi
  else
    log_failure_msg "${DNSCRYPT_PROXY_CONF} not found" && EXIT_STATUS=3
  fi
}

check_instance () {
  if [ -e ${DNSCRYPT_PROXY_CONF} ]; then
    DNSCRYPT_PROXY_INSTANCE=$(basename ${DNSCRYPT_PROXY_CONF} | sed 
's/.conf$//')
    DNSCRYPT_PROXY_PIDFILE=$(grep "^PidFile" ${DNSCRYPT_PROXY_CONF} | awk 
'{print $2}')

    status_of_proc -p "${DNSCRYPT_PROXY_PIDFILE}" ${DNSCRYPT_PROXY_BIN} \
      ${DNSCRYPT_PROXY_INSTANCE} 2>/dev/null || EXIT_STATUS=$?
  else
    log_failure_msg "${DNSCRYPT_PROXY_CONF} not found" && EXIT_STATUS=3
  fi
}

case "$1" in
  start)
    [ -d "${DNSCRYPT_PROXY_HOME}" ] || \
       mkdir -m 0555 "${DNSCRYPT_PROXY_HOME}"

    EXIT_STATUS=0

    get_config "$@"

    for DNSCRYPT_PROXY_CONF in ${DNSCRYPT_PROXY_CONFS}; do
      start_instance
    done

    exit ${EXIT_STATUS}
    ;;

  stop)
    EXIT_STATUS=0

    get_config "$@"

    for DNSCRYPT_PROXY_CONF in ${DNSCRYPT_PROXY_CONFS}; do
      stop_instance
    done

    exit ${EXIT_STATUS}
    ;;

  restart|force-reload)
    shift
    $0 stop ${@}
    $0 start ${@}
    ;;
    
  status)
    EXIT_STATUS=0

    get_config "$@"

    for DNSCRYPT_PROXY_CONF in ${DNSCRYPT_PROXY_CONFS}; do
      check_instance
    done

    exit ${EXIT_STATUS}
    ;;

  *)
    log_action_msg "Usage: /etc/init.d/dnscrypt-proxy 
{start|stop|restart|force-reload|status}"
    exit 1
    ;;

esac

exit 0

# vim: set ai sts=2 sw=2 tw=0 :