Adding New Hosts

This guide explains how to add a new machine configuration to the NixOS/Darwin system configuration.

Prerequisites

• Access to the target machine
• Hardware information (if adding a NixOS system)
• Understanding of the machine's intended purpose and configuration needs

Step-by-Step Process

1. Create Machine Directory

Create a new directory for your machine under machines/:

mkdir machines/[machine-name]
cd machines/[machine-name]

2. Generate Hardware Configuration (NixOS Only)

For NixOS systems, generate the initial hardware configuration:

# On the target machine
nixos-generate-config --show-hardware-config > hardware-configuration.nix

Copy this file to your machines/[machine-name]/ directory.

3. Create Machine Configuration

Create a default.nix file in your machine directory:

{
  inputs,
  outputs,
  lib,
  config,
  pkgs,
  ...
}: {
  imports = [
    # Include hardware configuration (NixOS only)
    ./hardware-configuration.nix

    # Add any machine-specific modules
    # ./custom-module.nix
  ];

  # Set state version
  dc-tec.stateVersion = "24.05";

  # Configure user settings
  dc-tec.user = {
    name = "your-username";
    fullName = "Your Full Name";
    email = "your@email.com";
  };

  # Enable desired modules
  dc-tec = {
    # Add your specific module configurations here
  };

  # System-specific configuration
  networking.hostName = "machine-name";

  # Add any additional system configuration
}

4. Add to Flake Configuration

Edit flake.nix and add your new machine to the appropriate outputs section:

For NixOS machines:

nixosConfigurations = {
  # ... existing machines ...

  your-machine = nixpkgs.lib.nixosSystem {
    specialArgs = {
      inherit inputs outputs;
      lib = lib "x86_64-linux";  # or "aarch64-linux"
    };
    modules = sharedModules ++ nixosModules ++ [ ./machines/your-machine/default.nix ];
  };
};

For Darwin machines:

darwinConfigurations = {
  # ... existing machines ...

  your-machine = darwin.lib.darwinSystem {
    specialArgs = {
      inherit inputs outputs;
      lib = lib "aarch64-darwin";  # or "x86_64-darwin"
    };
    modules = sharedModules ++ darwinModules ++ [ ./machines/your-machine/default.nix ];
  };
};

5. Configure Machine-Specific Settings

Customize your machine configuration based on its intended use:

Development Workstation

dc-tec.development = {
  enable = true;
  languages = {
    go.enable = true;
    python.enable = true;
    nodejs.enable = true;
  };
};

Server System

dc-tec.services = {
  ssh.enable = true;
  # Add other server services
};

Desktop System

dc-tec.desktop = {
  enable = true;
  # Configure desktop environment
};

6. Build and Test

Test your configuration:

# For NixOS
sudo nixos-rebuild test --flake .#your-machine

# For Darwin
darwin-rebuild check --flake .#your-machine

7. Deploy Configuration

Once tested, deploy the configuration:

# For NixOS
sudo nixos-rebuild switch --flake .#your-machine

# For Darwin
darwin-rebuild switch --flake .#your-machine

8. Document Your Machine

Create documentation for your new machine in docs/machines/your-machine.md following the format of existing machine documentation.

Common Configuration Patterns

Laptop Configuration

• Enable power management
• Configure display settings
• Set up wireless networking

Server Configuration

• Disable desktop environment
• Enable SSH and remote access
• Configure firewall rules
• Set up monitoring and logging

Development Machine

• Enable development tools
• Configure container support
• Set up language toolchains
• Enable virtualization

Troubleshooting

Build Failures

• Check syntax in your default.nix
• Ensure all imported modules exist
• Verify hardware configuration is correct

Module Conflicts

• Review enabled modules for conflicts
• Check module documentation for requirements
• Use lib.mkForce to override conflicting options

Hardware Issues

• Regenerate hardware configuration
• Check hardware-specific module requirements
• Review kernel and driver settings

Next Steps

After successfully adding your machine:

1. Update the documentation index
2. Test the configuration thoroughly
3. Add any machine-specific secrets to SOPS
4. Configure backups and maintenance schedules