Incorporate Nix Friday Feedback

default.nix

@@ -3,5 +3,8 @@
 }:
 import nixpkgs {
   inherit system;
-  overlays = [ (import ./overlay.nix) ];
+  overlays = [
+      (import ./overlay.nix)
+      (import ./extensions/overlay.nix)
+  ];
 }

mkDevShell/instrumentation.nix → extensions/hoststate-instrumentation.nix

@@ -1,10 +1,12 @@
-{ lib, pkgs, config }:
+{ lib, pkgs, config, ... }:
+with lib;
 let
   inherit (config)
     name
-    dev-ca-path
     static-dns
+    dev-ca-path
     ;
+
   installProjectCA = {
     name = "ca-install";
     help = "install dev CA";
@@ -54,11 +56,52 @@ let
     '';
   };
 in
-(
-  if static-dns == null || static-dns == "" then [ ]
-  else [ fqdnsActivate fqdnsDeactivate ]
-) ++
-(
-  if dev-ca-path == null || dev-ca-path == "" then [ ]
-  else [ installProjectCA uninstallProjectCA ]
-)
+{
+  options = {
+    dev-ca-path = mkOption {
+      type = types.str;
+      default = "";
+      description = ''
+        Path to a development CA.
+
+        Users can load/unload this dev CA easily and cleanly into their local
+        trust stores via a wrapper around mkcert third party tool so that browsers
+        and other tools would accept issued certificates under this CA as valid.
+
+        Use cases:
+         - Ship static dev certificates under version control and make them trusted
+           on user machines: add the rootCA under version control alongside the
+           your dev certificates.
+         - Provide users with easy and reliable CA bootstrapping through the mkcert
+           command: exempt this path from version control via .gitignore and have
+           users  easily and reliably bootstrap a dev CA infrastructure on first use.
+      '';
+    };
+    static-dns = mkOption {
+      type = types.attrs;
+      default = { };
+      description = ''
+        A list of static DNS entries, for which to enable instrumentation.
+
+        Users can enable/disable listed static DNS easily and cleanly
+        via a wrapper around the hostctl third party tool.
+      '';
+      example = {
+        "test.domain.local" = "172.0.0.1";
+        "shared.domain.link-local" = "169.254.0.5";
+      };
+    };
+  };
+  config = {
+    commands =
+      (
+        if static-dns == null || static-dns == "" then [ ]
+        else [ fqdnsActivate fqdnsDeactivate ]
+      ) ++
+      (
+        if dev-ca-path == null || dev-ca-path == "" then [ ]
+        else [ installProjectCA uninstallProjectCA ]
+      );
+  };
+}
+

extensions/overlay.nix

@@ -0,0 +1,5 @@
+final: prev:
+{
+  hostctl = prev.callPackage ./hostctl { };
+}
+

mkDevShell/options.nix

@@ -1,8 +1,6 @@
 { lib, pkgs, config, ... }:
 with lib;
 let
-  instrumentedCommands = import ./instrumentation.nix { inherit lib pkgs config; };
-
   resolveKey = key:
     let
       attrs = builtins.filter builtins.isString (builtins.split "\\." key);
@@ -139,27 +137,6 @@ in
       '';
     };
 
-    # exclusively consumed by command instrumentation
-    dev-ca-path = mkOption {
-      type = types.str;
-      default = "";
-      description = ''
-        Path to a development CA.
-
-        Users can load/unload this dev CA easily and cleanly into their local
-        trust stores via a wrapper around mkcert third party tool so that browsers
-        and other tools would accept issued certificates under this CA as valid.
-
-        Use cases:
-         - Ship static dev certificates under version control and make them trusted
-           on user machines: add the rootCA under version control alongside the
-           your dev certificates.
-         - Provide users with easy and reliable CA bootstrapping through the mkcert
-           command: exempt this path from version control via .gitignore and have
-           users  easily and reliably bootstrap a dev CA infrastructure on first use.
-      '';
-    };
-
     commands = mkOption {
       type = types.listOf (types.submodule { options = commandOptions; });
       default = [ ];
@@ -233,23 +210,6 @@ in
       '';
     };
 
-    # exclusively consumed by command instrumentation
-    static-dns = mkOption {
-      type = types.attrs;
-      default = { };
-      description = ''
-        A list of static DNS entries, for which to enable instrumentation.
-
-        Users can enable/disable listed static DNS easily and cleanly
-        via a wrapper around the hostctl third party tool.
-      '';
-      example = {
-        "test.domain.local" = "172.0.0.1";
-        "shared.domain.link-local" = "169.254.0.5";
-      };
-    };
-
-
   };
 
   config = {
@@ -263,7 +223,7 @@ in
           DEVSHELL_MENU
         '';
       }
-    ] ++ instrumentedCommands;
+    ];
 
     packages =
       lib.unique (

overlay.nix

@@ -2,5 +2,4 @@ final: prev:
 {
   devshell = prev.callPackage ./devshell { };
   mkDevShell = prev.callPackage ./mkDevShell { };
-  hostctl = prev.callPackage ./hostctl { };
 }

shell.nix

@@ -1,4 +1,9 @@
 #!/usr/bin/env nix-build
 # Used to test the shell
 { pkgs ? import ./. { } }:
-pkgs.mkDevShell.fromTOML ./devshell.toml
+pkgs.mkDevShell {
+  imports = [
+    (pkgs.mkDevShell.importTOML ./devshell.toml)
+    ./extensions/hoststate-instrumentation.nix
+  ];
+}