update-resolv-conf for openSUSE, using SUSE's netconfig with dirty tricks. No need for resolvconf.

update-resolv-conf

#!/bin/bash
# 
# Parses DHCP options from openvpn to update resolv.conf
# To use set as 'up' and 'down' script in your openvpn *.conf:
# up /etc/openvpn/update-resolv-conf
# down /etc/openvpn/update-resolv-conf
# 
# Used snippets of resolvconf script by Thomas Hood <jdthood@yahoo.co.uk> 
# and Chris Hanson
# Licensed under the GNU GPL.  See /usr/share/common-licenses/GPL. 
#
# Adjusted for openSUSE and its 'netconfig' component
# using dirty tricks by multiple1902, kodmasin and sebix.
# Supports DNS Servers and Searchnames.
# Preserves pre-existing DNS servers and search names.
#
# 05/2006 chlauber@bnc.ch
# 01/2012 multiple1902@gmail.com
# 01/2014 boris@kodmasin.net
# 04/2021 sebix@sebix.at
# 
# Example envs set from openvpn:
# foreign_option_1='dhcp-option DNS 193.43.27.132'
# foreign_option_2='dhcp-option DNS 193.43.27.133'
# foreign_option_3='dhcp-option DOMAIN be.bnc.ch'

[ -z "$DEBUG" ] || set -x
if [ -x "/usr/bin/logger" ]; then
    logger="/usr/bin/logger -t 'OpenVPN:update-resolve-conf'"
else
    logger=":"
fi

set -eu -o pipefail

function print_error {
    read line file <<<$(caller)
    $logger -s "An error occurred in line $line of file $file:"
    sed "${line}q;d" "$file" | xargs $logger -s -- 
}
trap print_error ERR

NETCONFIG="/sbin/netconfig"

if [ ! -x "$NETCONFIG" ] ; then
    $logger -s "[OpenVPN:update-resolve-conf] missing binary $NETCONFIG. Aborting.";
    exit 1;
fi
if [ -z "$script_type" ]; then
    $logger -s "[OpenVPN:update-resolve-conf] variable script_type is empty. Aborting.";
    exit 1;
fi
if [ -z "$dev" ]; then
    $logger -s "[OpenVPN:update-resolve-conf] variable dev is empty. Aborting.";
    exit 1;
fi

case $script_type in
up)
    IF_DNS_NAMESERVERS=''
    IF_DNS_SEARCHNAMES=''
    for optionname in ${!foreign_option_*} ; do
        option="${!optionname}"
        part1=$(echo "$option" | cut -d " " -f 1)
        $logger "[OpenVPN:update-resolve-conf] received option $option.";
        if [ "$part1" == "dhcp-option" ] ; then
            part2=$(echo "$option" | cut -d " " -f 2)
            part3=$(echo "$option" | cut -d " " -f 3)
            if [ "$part2" == "DNS" ] ; then
                IF_DNS_NAMESERVERS="$IF_DNS_NAMESERVERS $part3"
            elif [ "$part2" == "DOMAIN" ] ; then
                IF_DNS_SEARCHNAMES="$IF_DNS_SEARCHNAMES $part3"
            fi
        fi
    done
    $logger "[OpenVPN:update-resolve-conf] setting now DNSSERVERS='$IF_DNS_NAMESERVERS'"
    $logger "[OpenVPN:update-resolve-conf] setting now DNSSEARCH='$IF_DNS_SEARCHNAMES'"
    $NETCONFIG modify -i "$dev" -s vpn << EOF
DNSSERVERS='$IF_DNS_NAMESERVERS'
DNSSEARCH='$IF_DNS_SEARCHNAMES'
EOF
    ;;
down)
    $NETCONFIG remove -i "$dev" -s vpn
    ;;
esac