nix-config/modules/smb-mounts.nix

{
  pkgs,
  config,
  lib,
  ...
}:
let
  inherit (lib)
    any
    mkOption
    types
    flip
    attrNames
    mkMerge
    concatMap
    optional
    ;
  baseOptions = [
    "x-systemd.idle-timeout=60"
    "x-systemd.device-timeout=5s"
    "x-systemd.mount-timeout=5s"
  ];
in
{
  # Give users the ability to add their own smb shares
  home-manager.sharedModules = [
    {
      options.home.smb = mkOption {
        description = "Samba shares to be mountable under $HOME/smb";
        default = [ ];
        type = types.listOf (
          types.submodule (
            { config, ... }:
            {
              options = {
                localPath = mkOption {
                  description = "The path under which the share will be mounted. Defaults to the remotePath";
                  type = types.str;
                  default = config.remotePath;
                };
                address = mkOption {
                  description = "The remote share address";
                  type = types.str;
                  example = "10.1.2.5";
                };
                remotePath = mkOption {
                  description = "The remote share path";
                  type = types.str;
                  example = "data-10";
                };
                credentials = mkOption {
                  description = "A smb credential file to access the remote share";
                  type = types.path;
                };
                automatic = mkOption {
                  description = "Whether this share should be automatically mounted on boot";
                  default = false;
                  type = types.bool;
                };
              };
            }
          )
        );
      };
    }
  ];

  imports =
    let
      existingCfg = flip any (attrNames config.home-manager.users) (
        user: (config.home-manager.users.${user}.home.smb != [ ])
      );
    in
    [
      {
        environment.systemPackages = lib.optional existingCfg pkgs.cifs-utils;
        fileSystems = mkMerge (
          flip concatMap (attrNames config.home-manager.users) (
            user:
            let
              parentPath = "/home/${user}/smb";
              cfg = config.home-manager.users.${user}.home.smb;
              inherit (config.users.users.${user}) uid;
              inherit (config.users.groups.${user}) gid;
            in
            flip map cfg (cfg: {
              "${parentPath}/${cfg.localPath}" =
                let
                  options =
                    baseOptions
                    ++ [
                      "uid=${toString uid}"
                      "gid=${toString gid}"
                      "file_mode=0600"
                      "dir_mode=0700"
                      "credentials=${cfg.credentials}"
                      "x-systemd.automount"
                      "_netdev"
                    ]
                    ++ (optional (!cfg.automatic) "noauto");
                in
                {
                  inherit options;
                  device = "//${cfg.address}/${cfg.remotePath}";
                  fsType = "cifs";
                };
            })
          )
        );
      }
    ];
}