refactor: put namespaced vm code in module

Signed-off-by: Lander Van den Bulcke <landervandenbulcke@gmail.com>

hosts/heimdall/default.nix

@@ -19,6 +19,8 @@
     };
   };
 
+  boot.binfmt.emulatedSystems = [ "aarch64-linux" ];
+
   networking.hostName = "heimdall";
 
   security.pki.certificateFiles = [

hosts/servers/hosting-02.nix

@@ -1,4 +1,8 @@
-{ config, pkgs, ... }:
+{
+  config,
+  pkgs,
+  ...
+}:
 {
   networking.firewall = {
     enable = true;
@@ -11,85 +15,15 @@
     ];
   };
 
-  networking.iproute2.enable = true;
-  systemd.network.config = {
-    routeTables = {
-      vpn = 133;
-    };
-    addRouteTablesToIPRoute2 = true;
-  };
-
-  systemd.services."netns@" = {
-    description = "Network namespace %i";
-    serviceConfig = {
-      Type = "oneshot";
-      RemainAfterExit = true;
-      ExecStart = "${pkgs.iproute2}/bin/ip netns add %i";
-      ExecStop = "${pkgs.iproute2}/bin/ip netns del %i";
-    };
-  };
-
-  systemd.services."veth-setup@" = {
-    description = "Setup veth pair for %i namespace";
-    after = [ "netns@%i.service" ];
-    requires = [ "netns@%i.service" ];
-    serviceConfig = {
-      Type = "oneshot";
-      RemainAfterExit = true;
-      ExecStart =
-        let
-          script = pkgs.writers.writeBash "veth-up" ''
-            ns="$1"
-            ${pkgs.iproute2}/bin/ip link add veth-init-$ns type veth peer name veth-ns-$ns
-            ${pkgs.iproute2}/bin/ip link set veth-ns-$ns netns $ns
-            ${pkgs.iproute2}/bin/ip link set veth-init-$ns up
-            ${pkgs.iproute2}/bin/ip netns exec $ns ${pkgs.iproute2}/bin/ip link set veth-ns-$ns up
-            ${pkgs.iproute2}/bin/ip netns exec $ns ${pkgs.iproute2}/bin/ip addr add 10.0.0.2/24 dev veth-ns-$ns
-          '';
-        in
-        "${script} %i";
-      ExecStop = "${pkgs.iproute2}/bin/ip link del veth-%i";
-    };
-  };
-
-  systemd.network.networks."50-veth" = {
-    matchConfig.Name = "veth-init-vpn";
-    networkConfig = {
-      Address = "10.0.0.1/24";
-    };
-  };
-
-  systemd.services."wireguard-wg0".requires = [
-    "netns@vpn.service"
-    "veth-setup@vpn.service"
-  ];
-  networking.wireguard = {
+  services.namespaced-vpn = {
     enable = true;
-    useNetworkd = false;
-
-    interfaces.wg0 = {
-      ips = [
-        "10.64.244.95/32"
-        "fc00:bbbb:bbbb:bb01::1:f45e/128"
-      ];
-
-      peers = [
-        {
-          publicKey = "KkShcqgwbkX2A9n1hhST6qu+m3ldxdJ2Lx8Eiw6mdXw=";
-          allowedIPs = [
-            "0.0.0.0/0"
-            "::0/0"
-          ];
-          endpoint = "146.70.117.226:51820";
-          persistentKeepalive = 25;
-        }
-      ];
-
-      listenPort = 51820;
-      privateKeyFile = config.sops.secrets.wireguardKey.path;
-      socketNamespace = "init";
-      interfaceNamespace = "vpn";
-    };
+    ips = [
+      "10.64.244.95/32"
+      "fc00:bbbb:bbbb:bb01::1:f45e/128"
+    ];
+    publicKey = "KkShcqgwbkX2A9n1hhST6qu+m3ldxdJ2Lx8Eiw6mdXw=";
+    endpoint = "146.70.117.226:51820";
+    privateKeyFile = config.sops.secrets.wireguardKey.path;
   };
 
   environment.systemPackages = with pkgs; [

lib/hetzner.nix

@@ -17,7 +17,7 @@
     }:
     let
       diskConfig = import ./disk-config.nix { inherit disks nixpkgs; };
-      machineConfig = ../hosts/servers/${hostname}.nix;
+      machineConfig = import ../hosts/servers/${hostname}.nix;
     in
     nixpkgs.lib.nixosSystem {
       inherit system;
@@ -25,6 +25,7 @@
       modules = [
         inputs.disko.nixosModules.disko
         inputs.sops-nix.nixosModules.sops
+        inputs.self.nixosModules.namespaced-vpn
 
         diskConfig
 
@@ -32,10 +33,16 @@
           {
             config,
             lib,
+            modulesPath,
             pkgs,
             ...
           }:
           {
+            imports = [
+              (modulesPath + "/installer/scan/not-detected.nix")
+              (modulesPath + "/profiles/qemu-guest.nix")
+            ];
+
             boot = {
               loader.grub = {
                 devices = [ "/dev/sda" ];

modules/nixos/default.nix

@@ -1,3 +1,4 @@
 {
   # my-module = import ./my-module.nix
+  namespaced-vpn = import ./namespaced-vpn.nix;
 }

modules/nixos/namespaced-vpn.nix

@@ -0,0 +1,142 @@
+{
+  config,
+  lib,
+  pkgs,
+  ...
+}:
+with lib;
+let
+  cfg = config.services.namespaced-vpn;
+in
+{
+  options.services.namespaced-vpn = {
+    enable = mkEnableOption "namespaced vpn";
+
+    ips = mkOption {
+      type = types.listOf types.str;
+    };
+
+    publicKey = mkOption {
+      type = types.str;
+    };
+
+    endpoint = mkOption {
+      type = types.str;
+    };
+
+    privateKeyFile = mkOption {
+      type = types.path;
+    };
+
+    namespace = mkOption {
+      type = types.str;
+      default = "vpn";
+    };
+
+    wgInterface = mkOption {
+      type = types.str;
+      default = "wg0";
+    };
+
+    hostVethIP = mkOption {
+      type = types.str;
+      default = "10.10.10.1/30";
+    };
+
+    namespaceVethIP = mkOption {
+      type = types.str;
+      default = "10.10.10.2/30";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    networking.iproute2.enable = true;
+
+    systemd.services."netns@" = {
+      description = "Network namespace %i";
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStart = "${pkgs.iproute2}/bin/ip netns add %i";
+        ExecStop = "${pkgs.iproute2}/bin/ip netns del %i";
+      };
+    };
+
+    systemd.services."veth-setup@" = {
+      description = "Setup veth pair for %i namespace";
+      after = [ "netns@%i.service" ];
+      requires = [ "netns@%i.service" ];
+      serviceConfig = {
+        Type = "oneshot";
+        RemainAfterExit = true;
+        ExecStart =
+          let
+            script = pkgs.writers.writeBash "veth-up" ''
+              ns="$1"
+              ${pkgs.iproute2}/bin/ip link add veth-init-$ns type veth peer name veth-ns-$ns
+              ${pkgs.iproute2}/bin/ip link set veth-ns-$ns netns $ns
+              ${pkgs.iproute2}/bin/ip link set veth-init-$ns up
+              ${pkgs.iproute2}/bin/ip netns exec $ns ${pkgs.iproute2}/bin/ip link set veth-ns-$ns up
+              ${pkgs.iproute2}/bin/ip netns exec $ns ${pkgs.iproute2}/bin/ip addr add $NS_IP dev veth-ns-$ns
+              ${pkgs.iproute2}/bin/ip netns exec $ns ${pkgs.iproute2}/bin/ip route add $HOST_IP via $(echo $NS_IP |  sed -E 's/\/[0-9]+$//') dev veth-ns-$ns
+            '';
+          in
+          "${script} %i";
+        ExecStop = "${pkgs.iproute2}/bin/ip link del veth-%i";
+      };
+    };
+
+    systemd.services."veth-setup@${cfg.namespace}" = {
+      overrideStrategy = "asDropin";
+      environment = {
+        HOST_IP = cfg.hostVethIP;
+        NS_IP = cfg.namespaceVethIP;
+      };
+    };
+
+    systemd.network.networks."50-init-${cfg.namespace}" = {
+      matchConfig.Name = "veth-init-${cfg.namespace}";
+      networkConfig = {
+        Address = "${cfg.hostVethIP}";
+      };
+    };
+
+    systemd.services."wireguard-${cfg.wgInterface}".requires = [
+      "netns@${cfg.namespace}.service"
+      "veth-setup@${cfg.namespace}.service"
+    ];
+
+    systemd.network.wait-online.ignoredInterfaces = [
+      cfg.wgInterface
+      "veth-init-${cfg.namespace}"
+      "veth-ns-${cfg.namespace}"
+    ];
+
+    networking.wireguard = {
+      enable = true;
+      useNetworkd = false;
+
+      interfaces."${cfg.wgInterface}" = {
+        ips = cfg.ips;
+
+        peers = [
+          {
+            publicKey = cfg.publicKey;
+            allowedIPs = [
+              "0.0.0.0/0"
+              "::0/0"
+            ];
+            endpoint = cfg.endpoint;
+            persistentKeepalive = 25;
+          }
+        ];
+
+        listenPort = 51820;
+        privateKeyFile = cfg.privateKeyFile;
+        socketNamespace = "init";
+        interfaceNamespace = cfg.namespace;
+      };
+    };
+
+  };
+}