From 32f4cb5cbba313b7af2fce46139c04d9469cb72a Mon Sep 17 00:00:00 2001
From: Kleidi Bujari <mail@4kb.net>
Date: Fri, 24 Jan 2025 12:14:23 -0500
Subject: 25-jan sprint

---
 machines/xnet/net/default.nix | 125 ++++++++++++++++++++++++++++++++++--------
 machines/xnet/net/sshd.nix    |   4 +-
 2 files changed, 103 insertions(+), 26 deletions(-)

(limited to 'machines/xnet/net')

diff --git a/machines/xnet/net/default.nix b/machines/xnet/net/default.nix
index 2255f53..9673792 100644
--- a/machines/xnet/net/default.nix
+++ b/machines/xnet/net/default.nix
@@ -1,8 +1,60 @@
 { config, lib, ... }:
 let
   cfg = config.xnet.net;
-  inherit (lib) mkOption mkIf types;
-  prefix = "10.26.4";
+
+  inherit (builtins)
+    attrNames
+    attrValues
+    map
+    length
+    ;
+
+  inherit (lib)
+    concatLines
+    genAttrs
+    mapAttrsToList
+    mergeAttrsList
+    mkOption
+    mkIf
+    types
+    ;
+
+  # Networks are logical groupings of hosts wired together. This is
+  # accomplished using VLANS on the same layer 2 network.
+  #
+  # Hosts can hard code their spot on a network here. This module aims
+  # to generate network information for a host using this set of facts.
+  # The module should gracefully fall back to defaults if a given fact
+  # is not specified for the host consuming the module.
+  #
+  # A host will have it's /etc/hosts populated with all other hosts in
+  # a network to avoid a dynamic DNS server.
+  networks = {
+
+    # Open network for xnet hosts
+    plaza = {
+      mask = 24;
+      vlan = 88;
+      hosts = {
+        t1 = "10.88.88.1";
+        radon = "10.88.88.2";
+        iridium = "10.88.88.3";
+      };
+    };
+
+    # Reserved network for kubernetes related nodes. A distinct network
+    # is created here for hosts that provide resources to workers.
+    # Generally, nodes on this network are spawned dynamically and are
+    # not a part of this NixOS config directly, although they may boot
+    # from assets served from a node here.
+    kubenet = {
+      mask = 24;
+      vlan = 42;
+      hosts = {
+        iridium = "10.88.42.254";
+      };
+    };
+  };
 in
 {
   imports = [
@@ -10,35 +62,60 @@ in
   ];
 
   options.xnet.net = {
+    join = mkOption {
+      type = types.listOf (types.enum (attrNames networks));
+      default = [ ];
+      description = "Available networks.";
+    };
+
     interface = mkOption {
       type = types.str;
       default = "";
       description = "Network interface connecting to xnet.";
     };
-
-    addr = mkOption {
-      type = types.ints.between 0 255;
-      description = "Final octet for xnet address.";
-      example = 4;
-    };
   };
 
-  # TODO:
-  #   - Add assertion that each address is only used once across config
-  #   - Add each host to each other hosts dns configuration
-  config = mkIf (builtins.stringLength cfg.interface > 0) {
-    networking.vlans = {
-      "${cfg.interface}.4" = {
-        inherit (cfg) interface;
-        id = 4;
-      };
-    };
+  config = mkIf ((length cfg.join) > 0) {
+    systemd.network =
+      let
+        name = config.networking.hostName;
 
-    networking.interfaces = {
-      "${cfg.interface}.4".ipv4.addresses = [{
-        address = "${prefix}.${toString cfg.addr}";
-        prefixLength = 24;
-      }];
-    };
+        genConfig = net: {
+          netdevs."${toString networks.${net}.vlan}-${net}" = {
+            netdevConfig.Kind = "vlan";
+            netdevConfig.Name = net;
+            vlanConfig.Id = networks.${net}.vlan;
+          };
+
+          networks."10-${cfg.interface}" = {
+            matchConfig.Name = cfg.interface;
+            vlan = cfg.join;
+
+            # Accept DHCP on physical interface
+            DHCP = "ipv4";
+
+            # Network is up when xnet physical interface gets carrier
+            linkConfig.RequiredForOnline = "carrier";
+          };
+
+          networks."${toString networks.${net}.vlan}-${net}" = {
+            matchConfig.Name = net;
+
+            # Set up address for known host
+            address = [ "${networks.${net}.hosts.${name}}/${toString networks.${net}.mask}" ];
+          };
+        };
+
+        values = attrValues (genAttrs cfg.join genConfig);
+      in
+      { enable = true; } // mergeAttrsList values;
+
+    networking.extraHosts =
+      let
+        genHosts = net: concatLines
+          (mapAttrsToList (name: value: "${value} ${name} ${name}.${net}.4kb.net")
+            networks.${net}.hosts);
+      in
+      concatLines (map (net: genHosts net) cfg.join);
   };
 }
diff --git a/machines/xnet/net/sshd.nix b/machines/xnet/net/sshd.nix
index ef225db..b7cacc2 100644
--- a/machines/xnet/net/sshd.nix
+++ b/machines/xnet/net/sshd.nix
@@ -24,8 +24,8 @@ in
       settings = {
         UsePAM = true;
         X11Forwarding = false;
-        PermitRootLogin = "no";
-        PasswordAuthentication = false;
+        PermitRootLogin = "yes";
+        # PasswordAuthentication = false;
         Ciphers = [ "chacha20-poly1305@openssh.com" ];
         Macs = [ "hmac-sha2-512-etm@openssh.com" ];
         KexAlgorithms = [ "curve25519-sha256@libssh.org" ];
-- 
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