nix-config/modules/smb-mounts.nix

{
  pkgs,
  config,
  lib,
  ...
}: let
  inherit
    (lib)
    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 = [
    {
      environment.systemPackages = [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=${cfg.credentials}"
                      ]
                      ++ (optional (!cfg.automatic) "noauto");
                  in {
                    inherit options;
                    device = "//${cfg.address}/${cfg.remotePath}";
                    fsType = "cifs";
                  };
                }
              )
          )
        );
    }
  ];
}