Convert from cloud-init networking to static networking

This is honestly pretty ugly. The issue is that I want two different
IPv6 addresses on this server. I get one address for free as part of my
hosting agreement. The other I have to pay $0.01 per month for. The
address is routable, but it's not provided via cloud-init like the
initial address.

I therefore took the data from /var/lib/cloud/instance/network-config.json
and translated it into this configuration manually. It's dangerous - I
don't know when any of this information may change.

However, it works, and both addresses are now bound to eth0.

Notice that I set the network configuration name to "09-wan". This is
because the previous configuration using cloud-init created a network
configuration at /etc/systemd/network/10-cloud-init that has to be
manually removed or superseded.

sovr/etc/nixos/configuration.nix

@@ -8,8 +8,6 @@
   imports =
     [ # Include the results of the hardware scan.
       ./hardware-configuration.nix
-      # Include the home-manager configuration
-      <home-manager/nixos>
       inputs.sovr.nixosModules.default
     ];
 
@@ -31,15 +29,6 @@
     inputs.sovr.packages."${pkgs.system}".sovr-server
   ];
 
-  home-manager.useGlobalPkgs = true;
-  home-manager.users.eliribble = {
-    home.file.".config/nvim/after/ftplugin/html.vim".source = ./home/eliribble/config/nvim/after/ftplugin/html.vim;
-    home.file.".config/nvim/after/ftplugin/go.vim".source = ./home/eliribble/config/nvim/after/ftplugin/go.vim;
-    home.file.".config/tmux/tmux.conf".source = ./home/eliribble/config/tmux/tmux.conf;
-    home.homeDirectory = "/home/eliribble";
-    home.stateVersion = "24.11";
-    home.username = "eliribble";
-  };
   i18n.defaultLocale = "en_US.UTF-8";
 
   networking = {
@@ -74,7 +63,7 @@
 
   services.cloud-init = {
     enable = true;
-    network.enable = true;
+    network.enable = false;
   };
   services.openssh = {
     enable = true;
@@ -88,7 +77,29 @@
     sessionSecret = "secret";
   };
 
-  systemd.network.enable = true;
+  systemd.network = {
+    enable = true;
+    networks."09-wan" = {
+      address = [
+        "194.135.104.85/24"
+        "2605:e440::2:1d5/64"
+        "2605:e440::2:3e/64"
+      ];
+      dns = [
+        "8.8.8.8"
+	"8.8.4.4"
+	"2001:4860:4860::8888"
+	"2001:4860::8844"
+      ];
+      linkConfig.RequiredForOnline = "routable";
+      matchConfig.Name = "eth0";
+      routes = [
+        { Gateway = "194.135.104.1"; }
+	{ Gateway = "2605:e440::1"; }
+      ];
+    };
+  };
+
 
   # Set your time zone.
   time.timeZone = "America/Phoenix";

sovr/etc/nixos/flake.lock

@@ -1,5 +1,26 @@
 {
   "nodes": {
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1736373539,
+        "narHash": "sha256-dinzAqCjenWDxuy+MqUQq0I4zUSfaCvN9rzuCmgMZJY=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "bd65bc3cde04c16755955630b344bc9e35272c56",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "ref": "release-24.11",
+        "repo": "home-manager",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
       "locked": {
         "lastModified": 1735264675,
@@ -34,6 +55,7 @@
     },
     "root": {
       "inputs": {
+        "home-manager": "home-manager",
         "nixpkgs": "nixpkgs",
         "sovr": "sovr"
       }
@@ -43,11 +65,11 @@
         "nixpkgs": "nixpkgs_2"
       },
       "locked": {
-        "lastModified": 1735827455,
+        "lastModified": 1735922336,
-        "narHash": "sha256-BpqQu/opMGrr6xUbbFQy2bkEbUSQhbxN4X8M8DRun5I=",
+        "narHash": "sha256-pccBDqwpLTT24mwQTfLxDciSMg95FPhVy683FvUpkj4=",
         "ref": "refs/heads/main",
-        "rev": "950e618c387282e13e4ec865ae37d0e168b4469a",
+        "rev": "85fc0509c232e4073896de480a4dec94bb97547c",
-        "revCount": 60,
+        "revCount": 64,
         "type": "git",
         "url": "file:///home/eliribble/src/sovr.cloud"
       },

sovr/etc/nixos/flake.nix

@@ -3,11 +3,15 @@
 
   inputs = {
     # NixOS official package source, using the nixos-24.11 branch here
+    home-manager = {
+      url = "github:nix-community/home-manager/release-24.11";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-24.11";
     sovr.url = "git+file:///home/eliribble/src/sovr.cloud";
   };
 
-  outputs = { self, nixpkgs, sovr, ... }@inputs: {
+  outputs = { self, home-manager, nixpkgs, sovr, ... }@inputs: {
     nixosConfigurations.sovr = nixpkgs.lib.nixosSystem {
       specialArgs = { inherit inputs; };
       system = "x86_64-linux";
@@ -15,6 +19,12 @@
         # Import the previous configuration.nix we used,
         # so the old configuration file still takes effect
         ./configuration.nix
+	home-manager.nixosModules.home-manager
+	{
+	  home-manager.useGlobalPkgs = true;
+	  home-manager.useUserPackages = true;
+	  home-manager.users.eliribble = import ./home.nix;
+	}
       ];
     };
   };

sovr/etc/nixos/home.nix

@@ -0,0 +1,10 @@
+  { config, pkgs, ... }:
+
+  {
+    home.file.".config/nvim/after/ftplugin/html.vim".source = ./home/eliribble/config/nvim/after/ftplugin/html.vim;
+    home.file.".config/nvim/after/ftplugin/go.vim".source = ./home/eliribble/config/nvim/after/ftplugin/go.vim;
+    home.file.".config/tmux/tmux.conf".source = ./home/eliribble/config/tmux/tmux.conf;
+    home.homeDirectory = "/home/eliribble";
+    home.stateVersion = "24.11";
+    home.username = "eliribble";
+  }