add overlay for docker version for flake.nix

flake.nix

@@ -1,7 +1,6 @@
 {
-  
   description = "LAN NixOS configs";
-  # GitHub tokens must be provided outside this repository (local nix.conf, env, or deployment secrets).
+
   inputs = {
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-25.11";
     nixos-conf-editor.url = "github:snowfallorg/nixos-conf-editor";
@@ -12,31 +11,55 @@
   };
 
   outputs = { self, nixpkgs, nixos-conf-editor, home-manager, ... } @ inputs:
-    let system = "x86_64-linux"; in { 
+
+    let
+      system = "x86_64-linux";
+
+      # 🔧 Docker override (pin version here)
+      dockerOverlay = final: prev: {
+        docker = prev.docker_29;
+        docker_cli = prev.docker_29;
+      };
+
+    in {
+
       nixosConfigurations = {
-        # automatically use each host folder by name
+
         nixos = nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./hosts/nixos/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
               home-manager.users.nixos = import ./hosts/nixos/home.nix;
-                      
             }
           ];
 
-
-
           specialArgs = { inherit inputs; };
         };
+
 docker = nixpkgs.lib.nixosSystem {
   inherit system;
+
+  # 🔧 create custom pkgs with overlay
+  pkgs = import nixpkgs {
+    inherit system;
+
+    overlays = [
+      (final: prev: {
+        docker = prev.docker_29;
+        docker_cli = prev.docker_29;
+      })
+    ];
+  };
+
   modules = [
     ./hosts/docker/configuration.nix
     ./common/hardware-configuration.nix
+
     home-manager.nixosModules.home-manager {
       home-manager.useGlobalPkgs = true;
       home-manager.useUserPackages = true;
@@ -49,6 +72,7 @@
           modules = [
             ./hosts/kuma/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
@@ -56,11 +80,13 @@
             }
           ];
         };
+
         server = nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./hosts/server/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
@@ -68,44 +94,47 @@
             }
           ];
         };
+
         nix-cache = nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./hosts/nix-cache/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
               home-manager.users.nixos = import ./common/home.nix;
             }
           ];
-        
         };
+
         nix-minimal = nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./hosts/nix-minimal/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
               home-manager.users.nixos = import ./common/home.nix;
             }
           ];
-        
         };
+
         pxe-boot = nixpkgs.lib.nixosSystem {
           inherit system;
           modules = [
             ./hosts/pxe-boot/configuration.nix
             ./common/hardware-configuration.nix
+
             home-manager.nixosModules.home-manager {
               home-manager.useGlobalPkgs = true;
               home-manager.useUserPackages = true;
               home-manager.users.nixos = import ./common/home.nix;
             }
           ];
-        
         };
       };
     };