feat: introduce Oracle VMs and Hetzner VMs as hardware types

This includes aarch64-linux variants for these hosters.

Signed-off-by: Raito Bezarius <masterancpp@gmail.com>

common/default.nix

@@ -6,8 +6,8 @@
     ./hardening.nix
     ./nix.nix
     ./raito-proxy-aware-nginx.nix
-    ./raito-vm.nix
     ./sysadmin
+    ./hardware
     ./zsh.nix
   ];
 }

common/hardware/default.nix

@@ -0,0 +1,7 @@
+{ ... }: {
+  imports = [
+    ./raito-vm.nix
+    ./oracle-vm.nix
+    ./hetzner.nix
+  ];
+}

common/hardware/hetzner.nix

@@ -0,0 +1,76 @@
+
+{ lib, config, ... }:
+let
+  cfg = config.bagel.hardware.hetzner;
+  inherit (lib) mkEnableOption mkIf mkOption types;
+in
+{
+  options.bagel.hardware.hetzner = {
+    enable = mkEnableOption "Hetzner's hardware defaults";
+
+    platformType = mkOption {
+      # Only VMs are supported.
+      type = types.enum [ "virtual-machine" ];
+    };
+
+    system = mkOption {
+      # Only the aarch64-linux VM Hetzner is supported.
+      type = types.enum [ "aarch64-linux" ];
+    };
+
+    networking.wan = {
+      mac = mkOption {
+        type = types.str;
+        description = "MAC address of the WAN interface in the Hetzner machine";
+      };
+      address = mkOption {
+        type = types.listOf types.str;
+        description = "List of static addresses attached to the WAN interface";
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # A bunch of stuff is virtio.
+    boot.initrd.availableKernelModules = [
+      "xhci_pci"
+      "usbhid"
+      "sr_mod"
+      "virtio_gpu"
+      "virtio_scsi"
+      "virtio_rng"
+      "virtio_pci"
+    ];
+
+    boot.loader.systemd-boot.enable = true;
+    boot.loader.efi.canTouchEfiVariables = true;
+
+    networking.useDHCP = lib.mkDefault false;
+
+    # Stolen from the netplan provided by aarch64 Ubuntu images.
+    systemd.network.enable = true;
+    systemd.network.links."10-wan" = {
+      linkConfig.Name = "wan";
+      matchConfig.MACAddress = cfg.networking.mac;
+    };
+    systemd.network.networks."10-wan" = {
+      matchConfig.Name = "wan";
+      networkingConfig.Address = cfg.networking.address;
+      linkConfig.RequiredForOnline = true;
+      DHCP = "ipv4";
+      routes = [
+        {
+          routeConfig = {
+            Destination = "::/0";
+            GatewayOnLink = true;
+            Gateway = "fe80::1";
+          };
+        }
+      ];
+      dhcpV4Config = {
+        RouteMetric = 100;
+        UseMTU = true;
+      };
+    };
+  };
+}

common/hardware/oracle-vm.nix

@@ -0,0 +1,44 @@
+
+{ lib, config, ... }: 
+let
+  cfg = config.bagel.hardware.oracle-vm;
+  inherit (lib) mkEnableOption mkIf mkOption types;
+in
+{
+  options.bagel.hardware.oracle-vm = {
+    enable = mkEnableOption "Oracle's VM hardware defaults";
+
+    system = mkOption {
+      # Only the free Oracle VMs are supported.
+      type = types.enum [ "aarch64-linux" ];
+    };
+  };
+
+  config = mkIf cfg.enable {
+    boot.loader.systemd-boot.enable = true;
+    boot.loader.efi.canTouchEfiVariables = true;
+
+    boot.initrd.availableKernelModules = [ "xhci_pci" "virtio_pci" "usbhid" "sr_mod" ];
+    boot.initrd.kernelModules = [ ];
+    boot.kernelModules = [ ];
+    boot.extraModulePackages = [ ];
+
+    nixpkgs.hostPlatform = cfg.system;
+
+    # Enables DHCP on each ethernet and wireless interface. In case of scripted networking
+    # (the default) this is the recommended approach. When using systemd-networkd it's
+    # still possible to use this option, but it's recommended to use it in conjunction
+    # with explicit per-interface declarations with `networking.interfaces.<interface>.useDHCP`.
+    networking.useDHCP = lib.mkDefault false;
+    # Examples:
+    # 2: enp0s3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group default qlen 1000
+    #  link/ether 02:00:17:00:91:6e brd ff:ff:ff:ff:ff:ff
+    #  inet 10.0.0.94/24 brd 10.0.0.255 scope global dynamic noprefixroute enp0s3
+    #     valid_lft 44162sec preferred_lft 33362sec
+    #  inet6 fe80::17ff:fe00:916e/64 scope link 
+    #     valid_lft forever preferred_lft forever
+    # [root@build02-aarch64-lahfa:~]# ip r
+    # default via 10.0.0.1 dev enp0s3 proto dhcp src 10.0.0.94 metric 1002 mtu 9000
+    networking.interfaces.enp0s3.useDHCP = lib.mkDefault true;
+  };
+}