nixpkgs/modules/nixos/ports.nix

# NixOS Module for Port Management
#
# This module provides centralized port management across your NixOS systems.
# Define ports once and use them consistently across all services, with
# support for host-specific overrides.
#
# Usage in your NixOS configuration:
#
#   # In your flake.nix or configuration.nix:
#   imports = [ inputs.m3ta-nixpkgs.nixosModules.default ];
#
#   m3ta.ports = {
#     enable = true;
#
#     # Define your default ports
#     definitions = {
#       nginx = 80;
#       grafana = 3000;
#       prometheus = 9090;
#       homepage = 8080;
#       ssh = 22;
#     };
#
#     # Define host-specific overrides
#     hostOverrides = {
#       laptop = {
#         nginx = 8080;  # Use non-privileged port on laptop
#         ssh = 2222;
#       };
#       server = {
#         homepage = 3001;
#       };
#     };
#
#     # Optionally set the current hostname for automatic port resolution
#     currentHost = config.networking.hostName;
#   };
#
#   # Use ports in your configuration:
#   services.nginx.defaultHTTPListenPort = config.m3ta.ports.get "nginx";
#   services.grafana.settings.server.http_port = config.m3ta.ports.get "grafana";
#
#   # Or access all ports for the current host:
#   environment.etc."my-ports.json".text = builtins.toJSON config.m3ta.ports.all;
{
  config,
  lib,
  ...
}:
with lib; let
  cfg = config.m3ta.ports;

  portsLib = import ../../lib/ports.nix {inherit lib;};

  portHelpers =
    if cfg.enable
    then
      portsLib.mkPortHelpers {
        ports = cfg.definitions;
        hostPorts = cfg.hostOverrides;
      }
    else null;
in {
  options.m3ta.ports = {
    enable = mkEnableOption "centralized port management";

    definitions = mkOption {
      type = types.attrsOf types.port;
      default = {};
      description = "Default port definitions for services.";
    };

    hostOverrides = mkOption {
      type = types.attrsOf (types.attrsOf types.port);
      default = {};
      description = "Host-specific port overrides.";
    };

    currentHost = mkOption {
      type = types.str;
      default = config.networking.hostName;
      description = "Hostname to use for port resolution.";
    };

    # Internal computed options
    get = mkOption {
      type = types.raw;
      readOnly = true;
      internal = true;
    };

    getForHost = mkOption {
      type = types.raw;
      readOnly = true;
      internal = true;
    };

    all = mkOption {
      type = types.attrsOf types.port;
      readOnly = true;
      internal = true;
    };

    allForHost = mkOption {
      type = types.raw;
      readOnly = true;
      internal = true;
    };

    services = mkOption {
      type = types.listOf types.str;
      readOnly = true;
      internal = true;
    };
  };

  config = mkIf cfg.enable {
    m3ta.ports.get = service: portHelpers.getPort service cfg.currentHost;
    m3ta.ports.getForHost = host: service: portHelpers.getPort service host;
    m3ta.ports.all = portHelpers.getHostPorts cfg.currentHost;
    m3ta.ports.allForHost = portHelpers.getHostPorts;
    m3ta.ports.services = portHelpers.listServices;
  };
}