From 2030d4de3970c6401a71322fc7964d6b7e5a3f05 Mon Sep 17 00:00:00 2001
From: Felix Albrigtsen <felixalb@pvv.ntnu.no>
Date: Wed, 31 Jul 2024 11:23:00 +0200
Subject: [PATCH] fix-openstack-networking (!47)

Fix networking in Openstack.

This rewrites the systemd-networkd config, fixing both dhcp and manual address/route configurations.
Now, everything should behave predictably, routing NTNU-internal and NTNU-global addresses separately and properly across both ipv4 and ipv6.

Reviewed-on: https://git.pvv.ntnu.no/Drift/pvv-nixos-config/pulls/47
---
 hosts/ildkule/configuration.nix | 24 ++++++++++++++++++++----
 values.nix                      | 21 +++++++++++++++++++++
 2 files changed, 41 insertions(+), 4 deletions(-)

diff --git a/hosts/ildkule/configuration.nix b/hosts/ildkule/configuration.nix
index 99e14bf..276af5a 100644
--- a/hosts/ildkule/configuration.nix
+++ b/hosts/ildkule/configuration.nix
@@ -20,10 +20,26 @@
   zramSwap.enable = true;
 
   networking.hostName = "ildkule"; # Define your hostname.
-  systemd.network.networks."30-all" = values.defaultNetworkConfig // {
-    matchConfig.Name = "en*";
-    DHCP = "yes";
-    gateway = [ ];
+
+  # Main connection, using the global/floatig IP, for communications with the world
+  systemd.network.networks."30-ntnu-global" = values.openstackGlobalNetworkConfig // {
+    matchConfig.Name = "ens4";
+
+    # Add the global addresses in addition to the local address learned from DHCP
+    addresses = [
+      { addressConfig.Address = "${values.hosts.ildkule.ipv4_global}/32"; }
+      { addressConfig.Address = "${values.hosts.ildkule.ipv6_global}/128"; }
+    ];
+  };
+
+  # Secondary connection only for use within the university network
+  systemd.network.networks."40-ntnu-internal" = values.openstackLocalNetworkConfig // {
+    matchConfig.Name = "ens3";
+    # Add the ntnu-internal addresses in addition to the local address learned from DHCP
+    addresses = [
+      { addressConfig.Address = "${values.hosts.ildkule.ipv4}/32"; }
+      { addressConfig.Address = "${values.hosts.ildkule.ipv6}/128"; }
+    ];
   };
 
   # List packages installed in system profile
diff --git a/values.nix b/values.nix
index 0c68b65..2e11f4f 100644
--- a/values.nix
+++ b/values.nix
@@ -73,4 +73,25 @@ in rec {
     DHCP = "no";
   };
 
+  openstackGlobalNetworkConfig = {
+    networkConfig.IPv6AcceptRA = "yes";
+    dns = [ "129.241.0.200" "129.241.0.201" ];
+    domains = [ "pvv.ntnu.no" "pvv.org" ];
+    DHCP = "yes";
+  };
+
+  openstackLocalNetworkConfig = {
+    networkConfig.IPv6AcceptRA = "no";
+    dns = [ "129.241.0.200" "129.241.0.201" ];
+    domains = [ "pvv.ntnu.no" "pvv.org" ];
+    DHCP = "yes";
+
+    # Only use this network for link-local networking, not global/default routes
+    dhcpV4Config.UseRoutes = "no";
+    routes = [
+      { routeConfig = { Destination = "10.0.0.0/8"; Gateway = "_dhcp4"; }; }
+    ];
+
+    linkConfig.RequiredForOnline = "no";
+  };
 }