Improve usage of roles. It should be much easier to read and use now.

common/default.nix

@@ -100,7 +100,5 @@
   security.acme.defaults.email = "zuckerberg@neet.dev";
 
   # Enable Desktop Environment if this is a PC (machine role is "personal")
-  de.enable = (
+  de.enable = lib.mkDefault (config.thisMachine.hasRole."personal");
-    builtins.elem config.networking.hostName config.machines.roles.personal
-  );
 }

common/machine-info/default.nix

@@ -5,20 +5,9 @@
 
 let
   machines = config.machines.hosts;
-in
-{
-  imports = [
-    ./ssh.nix
-    ./roles.nix
-  ];
 
-  options.machines = {
+  hostOptionsSubmoduleType = lib.types.submodule {
-
-    hosts = lib.mkOption {
-      type = lib.types.attrsOf
-        (lib.types.submodule {
     options = {
-
       hostNames = lib.mkOption {
         type = lib.types.listOf lib.types.str;
         description = ''
@@ -26,21 +15,18 @@ in
           Used for automatically trusting hosts for ssh connections.
         '';
       };
-
       arch = lib.mkOption {
         type = lib.types.enum [ "x86_64-linux" "aarch64-linux" ];
         description = ''
           The architecture of this machine.
         '';
       };
-
       systemRoles = lib.mkOption {
         type = lib.types.listOf lib.types.str; # TODO: maybe use an enum?
         description = ''
           The set of roles this machine holds. Affects secrets available. (TODO add service config as well using this info)
         '';
       };
-
       hostKey = lib.mkOption {
         type = lib.types.str;
         description = ''
@@ -48,7 +34,6 @@ in
           and for decrypting secrets with agenix.
         '';
       };
-
       remoteUnlock = lib.mkOption {
         default = null;
         type = lib.types.nullOr (lib.types.submodule {
@@ -80,7 +65,6 @@ in
           };
         });
       };
-
       userKeys = lib.mkOption {
         default = [ ];
         type = lib.types.listOf lib.types.str;
@@ -90,7 +74,6 @@ in
           TODO: consider auto populating other programs that use ssh keys such as gitea
         '';
       };
-
       deployKeys = lib.mkOption {
         default = [ ];
         type = lib.types.listOf lib.types.str;
@@ -98,17 +81,30 @@ in
           The list of deployment keys. Each key here can be used to log into all other systems as `root`.
         '';
       };
-
       configurationPath = lib.mkOption {
         type = lib.types.path;
         description = ''
           The path to this machine's configuration directory.
         '';
       };
+    };
+  };
+in
+{
+  imports = [
+    ./ssh.nix
+    ./roles.nix
+  ];
 
+  options.machines = {
+    hosts = lib.mkOption {
+      type = lib.types.attrsOf hostOptionsSubmoduleType;
     };
-        });
   };
+
+  options.thisMachine.config = lib.mkOption {
+    # For ease of use, a direct copy of the host config from machines.hosts.${hostName}
+    type = hostOptionsSubmoduleType;
   };
 
   config = {
@@ -196,5 +192,12 @@ in
           builtins.map (p: { "${dirName p}" = p; }) propFiles;
       in
       properties ../../machines;
+
+    # Don't try to evaluate "thisMachine" when reflecting using moduleless.nix.
+    # When evaluated by moduleless.nix this will fail due to networking.hostName not
+    # existing. This is because moduleless.nix is not intended for reflection from the
+    # perspective of a perticular machine but is instead intended for reflecting on
+    # the properties of all machines as a whole system.
+    thisMachine.config = config.machines.hosts.${config.networking.hostName};
   };
 }

common/machine-info/roles.nix

@@ -1,19 +1,55 @@
 { config, lib, ... }:
 
-# Maps roles to their hosts
+# Maps roles to their hosts.
+# machines.withRole = {
+#   personal = [
+#     "machine1" "machine3"
+#   ];
+#   cache = [
+#     "machine2"
+#   ];
+# };
+#
+# A list of all possible roles
+# machines.allRoles = [
+#   "personal"
+#   "cache"
+# ];
+#
+# For each role has true or false if the current machine has that role
+# thisMachine.hasRole = {
+#   personal = true;
+#   cache = false;
+# };
 
 {
-  options.machines.roles = lib.mkOption {
+  options.machines.withRole = lib.mkOption {
     type = lib.types.attrsOf (lib.types.listOf lib.types.str);
   };
 
+  options.machines.allRoles = lib.mkOption {
+    type = lib.types.listOf lib.types.str;
+  };
+
+  options.thisMachine.hasRole = lib.mkOption {
+    type = lib.types.attrsOf lib.types.bool;
+  };
+
   config = {
-    machines.roles = lib.zipAttrs
+    machines.withRole = lib.zipAttrs
       (lib.mapAttrsToList
         (host: cfg:
           lib.foldl (lib.mergeAttrs) { }
             (builtins.map (role: { ${role} = host; })
               cfg.systemRoles))
         config.machines.hosts);
+
+    machines.allRoles = lib.attrNames config.machines.withRole;
+
+    thisMachine.hasRole = lib.mapAttrs
+      (role: cfg:
+        builtins.elem config.networking.hostName config.machines.withRole.${role}
+      )
+      config.machines.withRole;
   };
 }

common/machine-info/ssh.nix

@@ -39,6 +39,6 @@ in
         builtins.map
           (host: machines.hosts.${host}.hostKey)
           hosts)
-      machines.roles;
+      machines.withRole;
   };
 }

common/nix-builder.nix

@@ -1,18 +1,14 @@
 { config, lib, ... }:
 
 let
-  builderRole = "nix-builder";
   builderUserName = "nix-builder";
 
-  machinesByRole = role: lib.filterAttrs (hostname: cfg: builtins.elem role cfg.systemRoles) config.machines.hosts;
+  builderRole = "nix-builder";
-  otherMachinesByRole = role: lib.filterAttrs (hostname: cfg: hostname != config.networking.hostName) (machinesByRole role);
+  builders = config.machines.withRole.${builderRole};
-  thisMachineHasRole = role: builtins.hasAttr config.networking.hostName (machinesByRole role);
+  thisMachineIsABuilder = config.thisMachine.hasRole.${builderRole};
-
-  builders = machinesByRole builderRole;
-  thisMachineIsABuilder = thisMachineHasRole builderRole;
 
   # builders don't include themselves as a remote builder
-  otherBuilders = lib.filterAttrs (hostname: cfg: hostname != config.networking.hostName) builders;
+  otherBuilders = lib.filter (hostname: hostname != config.networking.hostName) builders;
 in
 lib.mkMerge [
   # configure builder
@@ -40,9 +36,9 @@ lib.mkMerge [
     nix.distributedBuilds = true;
 
     nix.buildMachines = builtins.map
-      (builderCfg: {
+      (builderHostname: {
-        hostName = builtins.elemAt builderCfg.hostNames 0;
+        hostName = builderHostname;
-        system = builderCfg.arch;
+        system = config.machines.hosts.${builderHostname}.arch;
         protocol = "ssh-ng";
         sshUser = builderUserName;
         sshKey = "/etc/ssh/ssh_host_ed25519_key";
@@ -50,7 +46,7 @@ lib.mkMerge [
         speedFactor = 10;
         supportedFeatures = [ "nixos-test" "benchmark" "big-parallel" "kvm" ];
       })
-      (builtins.attrValues otherBuilders);
+      otherBuilders;
 
     # It is very likely that the builder's internet is faster or just as fast
     nix.extraOptions = ''

common/server/gitea-actions-runner.nix

@@ -9,10 +9,7 @@
 # TODO: skipping running inside of nixos container for now because of issues getting docker/podman running
 
 let
-  runnerRole = "gitea-actions-runner";
+  thisMachineIsARunner = config.thisMachine.hasRole."gitea-actions-runner";
-  runners = config.machines.roles.${runnerRole};
-  thisMachineIsARunner = builtins.elem config.networking.hostName runners;
-
   containerName = "gitea-runner";
 in
 {

flake.nix

@@ -84,13 +84,11 @@
 
   outputs = { self, nixpkgs, ... }@inputs:
     let
-      machines = (import ./common/machine-info/moduleless.nix
+      machineHosts = (import ./common/machine-info/moduleless.nix
         {
           inherit nixpkgs;
           assertionsModule = "${nixpkgs}/nixos/modules/misc/assertions.nix";
-        }).machines;
+        }).machines.hosts;
-      machineHosts = machines.hosts;
-      machineRoles = machines.roles;
     in
     {
       nixosConfigurations =
@@ -115,10 +113,7 @@
 
                 home-manager.useGlobalPkgs = true;
                 home-manager.useUserPackages = true;
-                home-manager.users.googlebot = import ./home/googlebot.nix {
+                home-manager.users.googlebot = import ./home/googlebot.nix;
-                  inherit hostname;
-                  inherit machineRoles;
-                };
               };
 
               # because nixos specialArgs doesn't work for containers... need to pass in inputs a different way

home/googlebot.nix

@@ -1,9 +1,8 @@
-{ hostname, machineRoles }:
+{ config, lib, pkgs, osConfig, ... }:
-{ config, lib, pkgs, ... }:
 
 let
   # Check if the current machine has the role "personal"
-  thisMachineIsPersonal = builtins.elem hostname machineRoles.personal;
+  thisMachineIsPersonal = osConfig.thisMachine.hasRole."personal";
 in
 {
   home.username = "googlebot";