OpenVPN with multiple routing tables

Question

I am using a openvpn client, with my default configuration the default GW is overwritten. (redirect gateway on the server)
I have 2 routing tables on my linux client, 1 (default eth0), 100 = tun0 which is added by my up script.
What i need is to have split routing using 2 different routing tables.

openvpn client config:

client
dev tun
proto udp
remote blea.com
auth-user-pass
persist-key
persist-tun
remote-cert-tls server
reneg-sec 0
keepalive 10 60
route-nopull
pull-filter ignore "ifconfig-ipv6"
script-security 2
up /etc/openvpn/route-up.sh
mute-replay-warnings
explicit-exit-notify 3
cipher AES-256-CBC
auth SHA512
tls-version-min 1.2

route-up script:

if [ $(/bin/cat /etc/iproute2/rt_tables | /bin/grep $dev | /usr/bin/wc -l) -eq 0 ]; then
/bin/echo "100 tun0" >> /etc/iproute2/rt_tables

/bin/ip route add default via $route_vpn_gateway dev $dev table $dev

There is 1 problem, when using route-nopull the $route_vpn_gateway environment variable is not populated.
When i disable route-nopull the default gateway on my default routing table is overwritten so all the traffic goes through the tunnel.
I have no access to the server so i cannot change anything there.
The default GW which i get served by the OpenVPN server is dynamic, so i cannot set this static.

How to get around this?

Answer 1

One way to do this is to use the route-noexec option (instead of route-nopull). This will fully populate your route-* environment variables but won't actually modify your route table, it will leave all the route modification to your route-up.sh