From 7128a728b86ef1722d628cffc3138450a65c98be Mon Sep 17 00:00:00 2001
From: Ben Vincent <ben@unkin.net>
Date: Sun, 7 Sep 2025 15:49:58 +1000
Subject: [PATCH] feat: update ospf source for learned routes

- enable changing the source address for learned ospf routes
- this enables the loopback0 interface to be used as a default src address
- ensure k8s nodes use loopback0 as default src
- ensure incus nodes use loopback0 as default src
---
 hieradata/roles/infra/incus/node.yaml    | 2 ++
 hieradata/roles/infra/k8s/node.yaml      | 2 ++
 modules/frrouting/manifests/init.pp      | 2 ++
 modules/frrouting/templates/frr.conf.erb | 8 ++++++++
 4 files changed, 14 insertions(+)

diff --git a/hieradata/roles/infra/incus/node.yaml b/hieradata/roles/infra/incus/node.yaml
index 99e0815..fc835cd 100644
--- a/hieradata/roles/infra/incus/node.yaml
+++ b/hieradata/roles/infra/incus/node.yaml
@@ -158,6 +158,8 @@ networking::interfaces:
 # frrouting
 exporters::frr_exporter::enable: true
 frrouting::ospfd_router_id: "%{hiera('networking_loopback0_ip')}"
+frrouting::ospf_preferred_source_enable: true
+frrouting::ospf_preferred_source: "%{hiera('networking_loopback0_ip')}"
 frrouting::ospfd_redistribute:
   - connected
 frrouting::ospfd_interfaces:
diff --git a/hieradata/roles/infra/k8s/node.yaml b/hieradata/roles/infra/k8s/node.yaml
index 67e7c01..366a928 100644
--- a/hieradata/roles/infra/k8s/node.yaml
+++ b/hieradata/roles/infra/k8s/node.yaml
@@ -100,6 +100,8 @@ profiles::consul::client::node_rules:
 # frrouting
 exporters::frr_exporter::enable: true
 frrouting::ospfd_router_id: "%{hiera('networking_loopback0_ip')}"
+frrouting::ospf_preferred_source_enable: true
+frrouting::ospf_preferred_source: "%{hiera('networking_loopback0_ip')}"
 frrouting::ospfd_redistribute:
   - connected
 frrouting::ospfd_interfaces:
diff --git a/modules/frrouting/manifests/init.pp b/modules/frrouting/manifests/init.pp
index 6c7d755..92fcdcb 100644
--- a/modules/frrouting/manifests/init.pp
+++ b/modules/frrouting/manifests/init.pp
@@ -14,6 +14,8 @@ class frrouting (
   Optional[String] $mpls_ldp_router_id       = undef,
   Optional[String] $mpls_ldp_transport_addr  = undef,
   Array[String] $mpls_ldp_interfaces         = [],
+  Boolean $ospf_preferred_source_enable      = false,
+  Optional[Stdlib::IP::Address] $ospf_preferred_source = undef,
 ) {
 
   $daemons_defaults = {
diff --git a/modules/frrouting/templates/frr.conf.erb b/modules/frrouting/templates/frr.conf.erb
index 4e6668b..e2c7040 100644
--- a/modules/frrouting/templates/frr.conf.erb
+++ b/modules/frrouting/templates/frr.conf.erb
@@ -43,3 +43,11 @@ mpls ldp
  exit-address-family
 exit
 <% end -%>
+<% if @ospf_preferred_source_enable && @ospf_preferred_source -%>
+ip prefix-list ANY seq 5 permit 0.0.0.0/0 le 32
+route-map OSPF-SRC permit 10
+ match ip address prefix-list ANY
+ set src <%= @ospf_preferred_source %>
+exit
+ip protocol ospf route-map OSPF-SRC
+<% end -%>