pass file-system-derived hostname to host configurations

Author: phaer

docs/folder-structure.md

@@ -126,7 +126,7 @@ command = "memcached"
 
 ### `hosts/<hostname>/(default.nix|configuration.nix|darwin-configuration.nix,system-configuration.nix)`
 
-Each folder contains either a NixOS or nix-darwin configuration:
+Each folder contains either a NixOS, [nix-darwin](https://github.com/LnL7/nix-darwin) or [system-manager](https://github.com/numtide/system-manager) configuration:
 
 #### `configuration.nix`
 
@@ -138,6 +138,7 @@ Additional values passed:
 * `flake` maps to `inputs.self`.
 * `perSystem`: contains the packages of all the inputs, filtered per system.
     Eg: `perSystem.nixos-anywhere.default` is a shorthand for `inputs.nixos-anywhere.packages.<system>.default`.
+* `hostname` as per the host directory name.
 
 Flake outputs:
 
@@ -182,6 +183,7 @@ Additional values passed:
 * `flake` maps to `inputs.self`.
 * `perSystem`: contains the packages of all the inputs, filtered per system.
     Eg: `perSystem.nixos-anywhere.default` is a shorthand for `inputs.nixos-anywhere.packages.<system>.default`.
+* `hostname` as per the host directory name.
 
 Flake outputs:
 
@@ -207,6 +209,7 @@ Additional values passed:
 * `flake` maps to `inputs.self`.
 * `perSystem`: contains the packages of all the inputs, filtered per system.
     Eg: `perSystem.nixos-anywhere.default` is a shorthand for `inputs.nixos-anywhere.packages.<system>.default`.
+* `hostname` as per the host directory name.
 
 Flake outputs:
 
@@ -234,6 +237,7 @@ Additional values passed:
 
 * `inputs` maps to the current flake inputs.
 * `flake` maps to `inputs.self`.
+* `hostname` as per the host directory name.
 
 Expected return value:
 

lib/default.nix

@@ -310,7 +310,7 @@ let
         let
           loadDefaultFn = { class, value }@inputs: inputs;
 
-          loadDefault = path: loadDefaultFn (import path { inherit flake inputs; });
+          loadDefault = hostname: path: loadDefaultFn (import path { inherit flake inputs hostname; });
 
           loadNixOS = hostname: path: {
             class = "nixos";
@@ -319,7 +319,7 @@ let
                 perSystemModule
                 path
               ] ++ mkHomeUsersModule hostname home-manager.nixosModules.default;
-              inherit specialArgs;
+              specialArgs = specialArgs // { inherit hostname; };
             };
           };
 
@@ -337,12 +337,12 @@ let
                   perSystemModule
                   path
                 ] ++ mkHomeUsersModule hostname home-manager.darwinModules.default;
-                inherit specialArgs;
+                specialArgs = specialArgs // { inherit hostname; };
               };
             };
 
           loadSystemManager =
-            _hostname: path:
+            hostname: path:
             let
               system-manager =
                 inputs.system-manager
@@ -355,15 +355,15 @@ let
                   perSystemModule
                   path
                 ];
-                extraSpecialArgs = specialArgs;
+                extraSpecialArgs = specialArgs // { inherit hostname; };
               };
             };
 
           loadHost =
             name:
             { path, type }:
             if builtins.pathExists (path + "/default.nix") then
-              loadDefault (path + "/default.nix")
+              loadDefault name (path + "/default.nix")
             else if builtins.pathExists (path + "/configuration.nix") then
               loadNixOS name (path + "/configuration.nix")
             else if builtins.pathExists (path + "/darwin-configuration.nix") then