Add config-manager

config-manager/default.nix

@@ -0,0 +1,62 @@
+{  pkgs, lib, config, ... }:
+let
+  config-manager = let
+    flakePath = config.config-manager.flakePath;
+    nixosConfiguration = config.config-manager.nixosConfiguration;
+  in
+    if flakePath == "" then
+      throw "'config-manager.flakePath' cannot be empty"
+    else
+      pkgs.writeShellScriptBin "cm" ''
+        help() {
+          cat << EOF
+Usage:
+  cm [flag]
+
+Flags:
+  --update    updates the flake
+  --switch    rebuilds + switches configuration
+EOF
+        }
+
+        update() {
+          echo -e "\033[0;31mUPDATING FLAKE"
+          sudo nix flake update
+        }
+
+        switch() {
+          echo -e "\033[0;31mREBUILDING + SWITCHING CONFIG"
+          sudo nixos-rebuild switch --flake ${flakePath}#${nixosConfiguration}
+        }
+
+        case $1 in
+          --update)
+            update ;;
+          --switch)
+            switch ;;
+          --help | *)
+            help ;;
+    esac
+      '';
+in
+{
+  options = {
+    config-manager = {
+      flakePath = lib.mkOption {
+        type = lib.types.str;
+        default = "";
+        description = "path to this flake";
+      };
+
+      nixosConfiguration = lib.mkOption {
+        type = lib.types.str;
+        default = config.networking.hostName;
+        description = "what nixosConfiguration to use";
+      };
+    };
+  };
+
+  config = {
+    environment.systemPackages = [ config-manager ];
+  };
+}