Add support to configure policy based routing

[ubuntu-server-builder]

This bug was originally filed in Launchpad as LP: #1807297

Launchpad details

affected_projects = []
assignee = holmanb
assignee_name = Brett Holman
date_closed = None
date_created = 2018-12-07T01:39:53.561170+00:00
date_fix_committed = None
date_fix_released = None
id = 1807297
importance = high
is_complete = False
lp_url = https://bugs.launchpad.net/cloud-init/+bug/1807297
milestone = None
owner = gjayavelu
owner_name = Giridhar Jayavelu
private = False
status = triaged
submitter = gjayavelu
submitter_name = Giridhar Jayavelu
tags = []
duplicates = []

Launchpad user Giridhar Jayavelu(gjayavelu) wrote on 2018-12-07T01:39:53.561170+00:00

When there are multiple interfaces with their own default gateways, this could result in asymmetric routing. In order to solve this, policy based routing would have to be configured.

• There is already support to configure routes in cloud-init, but it misses ability to specify routing table.
• Need ability to create routing table entries in /etc/iproute2/rt_tables
• Configure routing table lookup for a given network.

Here is a sample configuration: echo "100 eth0" >> /etc/iproute2/rt_tables echo "101 eth1" >> /etc/iproute2/rt_tables

auto eth0 iface eth0 inet static address 10.172.142.37/24 dns-nameservers 10.172.40.1 gateway 10.172.142.253 up ip rule add from 10.172.142.0/24 lookup eth0 up ip route add 10.172.142.0/24 dev eth0 table eth0 up ip route add default via 10.172.142.253 table eth0

auto eth1 iface eth1 inet static address 10.172.144.56/24 dns-nameservers 10.172.40.1 gateway 10.172.144.253 up ip rule add from 10.172.144.0/24 lookup eth1 up ip route add 10.172.144.0/24 dev eth1 table eth1 up ip route add default via 10.172.144.253 table eth1

[ubuntu-server-builder]

Launchpad user Ryan Harper(raharper) wrote on 2019-07-18T21:44:10.266016+00:00

Hi,

Thanks for filing the bug. This is a valid scenario.