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matthiassb/dns-sync.sh

Last active August 24, 2024 09:43
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Revisions

  1. matthiassb revised this gist Jul 23, 2018. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion dns-sync.sh
    View file
    Original file line number Diff line number Diff line change
    @@ -5,7 +5,7 @@
    # Required-Stop:
    # Default-Start: S
    # Default-Stop:
    # Short-Description: Synchronizes /etc/resolv.conf in WLS with Windows DNS
    # Short-Description: Synchronizes /etc/resolv.conf in WLS with Windows DNS - Matthias Brooks
    ### END INIT INFO

    PATH=/sbin:/bin
  2. matthiassb created this gist Jul 23, 2018.
    92 changes: 92 additions & 0 deletions dns-sync.sh
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,92 @@
    #! /bin/bash
    ### BEGIN INIT INFO
    # Provides: dns-sync
    # Required-Start:
    # Required-Stop:
    # Default-Start: S
    # Default-Stop:
    # Short-Description: Synchronizes /etc/resolv.conf in WLS with Windows DNS
    ### END INIT INFO

    PATH=/sbin:/bin
    PS=/mnt/c/Windows/System32/WindowsPowerShell/v1.0/powershell.exe

    . /lib/init/vars.sh
    . /lib/lsb/init-functions

    do_start () {
    while true
    do
    #Retrieve nameservers from via Powershell
    TEMPFILE=$(mktemp)
    $PS -Command "Get-DnsClientServerAddress -AddressFamily IPv4 | Select-Object -ExpandProperty ServerAddresses" > $TEMPFILE
    /usr/bin/awk '!x[$0]++' $TEMPFILE > $TEMPFILE.2
    IFS=$'\r\n' GLOBIGNORE='*' command eval 'UNIQUE_NAMESERVERS=($(cat $TEMPFILE.2))'
    rm -f $TEMPFILE $TEMPFILE.2

    #Retrive search domains via powershell
    IFS=$'\r\n' GLOBIGNORE='*' command eval 'SEARCH_DOMAIN=($($PS -Command "Get-DnsClientGlobalSetting | Select-Object -ExpandProperty SuffixSearchList"))'
    UNIQUE_SEARCH_DOMAIN=($(/usr/bin/tr ' ' '\n' <<< "${SEARCH_DOMAIN[@]}" | /usr/bin/sort -u | /usr/bin/tr '\n' ' '))


    #Modify /etc/resolv.conf
    touch /etc/resolv.conf
    sed -i '/nameserver/d' /etc/resolv.conf > /dev/null 2>&1 || true
    sed -i '/search/d' /etc/resolv.conf > /dev/null 2>&1 || true

    for i in "${UNIQUE_NAMESERVERS[@]}"
    do
    echo "nameserver ${i}" >> /etc/resolv.conf
    done
    if [ ${#UNIQUE_SEARCH_DOMAIN[@]} -ne 0 ]; then
    echo "search ${UNIQUE_SEARCH_DOMAIN[@]}" >> /etc/resolv.conf
    fi
    sleep 15
    done
    }

    do_status () {
    PID=$(cat /var/run/dns-sync.pid 2>/dev/null)
    if [ "$PID" == "" ]; then
    echo "dns-sync is not running"
    return
    fi

    if ps -p $PID > /dev/null
    then
    echo "dns-sync is running"
    else
    echo "dns-sync is not running"
    fi
    }

    case "$1" in
    start|"")
    kill $(cat /var/run/dns-sync.pid >/dev/null 2>&1) > /dev/null 2>&1 || true
    do_start &
    DO_SYNC_PID=$!
    echo "${DO_SYNC_PID}" > /var/run/dns-sync.pid
    ;;
    restart|reload|force-reload)
    echo "Error: argument '$1' not supported" >&2
    exit 3
    ;;
    stop)
    PID=$(cat /var/run/dns-sync.pid)
    if ps -p $PID > /dev/null
    then
    kill -9 $(cat /var/run/dns-sync.pid)
    echo "dns-sync stopped"
    else
    echo "dns-sync is not running"
    fi
    ;;
    status)
    do_status
    exit $?
    ;;
    *)
    echo "Usage: dns-sync.sh [start|stop]" >&2
    exit 3
    ;;
    esac