Samba

From NixOS Wiki
Jump to: navigation, search

This guide will help you on how to use samba on nixos.

Samba Client

cifs mount

The following snippets shows how to mount a CIFS (Windows) share in NixOS. Replace all <FIELDS> with concrete values:

{
  fileSystems."/mnt/share" = {
      device = "//<IP_OR_HOST>/path/to/share";
      fsType = "cifs";
      options = let
        # this line prevents hanging on network split
        automount_opts = "x-systemd.automount,noauto,x-systemd.idle-timeout=60,x-systemd.device-timeout=5s,x-systemd.mount-timeout=5s";

      in ["${automount_opts},credentials=/etc/nixos/smb-secrets"];
  };
}

Also create /etc/nixos/smb-secrets with the following content (domain= can be optional)

username=<USERNAME>
domain=<DOMAIN>
password=<PASSWORD>

Firewall

Samba discovery of machines and shares may need the firewall to be tuned (source): in /etc/nixos/configuration.nix, add:

networking.firewall.extraCommands = ''iptables -t raw -A OUTPUT -p udp -m udp --dport 137 -j CT --helper netbios-ns";

Browsing samba shares with GVFS

Many GTK-based file managers like Nautilus, Thunar, and PCManFM can browse samba shares thanks to GVFS. GVFS is a dbus daemon which must be running for this to work. If you use Gnome, you have nothing to do as the module already enables it for you, but in less full-featured desktop environments, some further configuration options are needed.

The generic way of enabling GVFS is to add this in /etc/nixos/configuration.nix:

services.gvfs.enable = true;

There are however some special cases.

XFCE

Xfce comes with a slimmed-down version of GVFS by default which comes with samba support compiled out. To have smb:// support in Thunar, we will use GNOME's full-featured version of GVFS:

  services.gvfs = {
    enable = true;
    package = lib.mkForce pkgs.gnome3.gvfs;
  };
No desktop environment

GVFS relies on polkit to gain privileges for some operations. Polkit needs an authentication agent to ask for credentials. Desktop environments usually provide one but if you have no desktop environment, you may have to install one yourself:

Excerpt of /etc/nixos/configuration.nix:

environment.systemPackages = with pkgs; [ lxqt.lxqt-policykit ]; # provides a default authentification client for policykit


DBUS

Furthermore, if you happen to start your Window Manager directly, via .xinitrc, or directly invoke a Wayland compositor such as Sway, you should ensure that you launch dbus at startup in your session and export its environment. If you do not have a dbus session in your environment, you will see errors such as "Operation not supported" when attempting to browse the network.

For example, if you are using .xinitrc, you could invoke dbus-launch:

export `dbus-launch` # starts dbus and exports its address
exec xterm # your prefered Window Manager

(You need to restart your Window Manager to have the changes in .xinitrc to take place.)

If you are using a Wayland compositor like Sway, you can run it under dbus-run-session for the same effect:

dbus-run-session sway

(Because dbus-run-session exits when the child process exits, it is only appropriate to use dbus-run-session with a process that will be running during the entire session. This is the case for Wayland compositors, but is not necessarily true for all configurations of X11 window managers.)

Samba Server

excerpt of /etc/nixos/configuration.nix

services.samba = {
  enable = true;
  securityType = "user";
  extraConfig = ''
    workgroup = WORKGROUP
    server string = smbnix
    netbios name = smbnix
    security = user 
    #use sendfile = yes
    #max protocol = smb2
    hosts allow = 192.168.0  localhost
    hosts deny = 0.0.0.0/0
    guest account = nobody
    map to guest = bad user
  '';
  shares = {
    public = {
      path = "/mnt/Shares/Public";
      browseable = "yes";
      "read only" = "no";
      "guest ok" = "yes";
      "create mask" = "0644";
      "directory mask" = "0755";
      "force user" = "username";
      "force group" = "groupname";
    };
    private = {
      path = "/mnt/Shares/Private";
      browseable = "yes";
      "read only" = "no";
      "guest ok" = "no";
      "create mask" = "0644";
      "directory mask" = "0755";
      "force user" = "username";
      "force group" = "groupname";
    };
  };
};

If your firewall is enabled, or if you consider enabling it:

networking.firewall.enable = true;
networking.firewall.allowPing = true;
networking.firewall.allowedTCPPorts = [ 445 139 ];
networking.firewall.allowedUDPPorts = [ 137 138 ];

Samba should startup afterwards.

If you plan to access a share as a user on the server, you'll need to run smbpasswd -a <user> as root to set the password.

stopping/restarting the services

# systemctl stop samba
# systemctl start samba
# systemctl restart samba

Use Cases

Apple Time Machine

nixpkgs includes Samba4.8-git, which adds support for using shares for Time Machine backups on macOS 10.12+. Example configuration:

services.samba = {
  package = pkgs.sambaMaster;
  shares = {
    tm_share = {
        path = "/mnt/Shares/tm_share";
        "valid users" = "username";
        public = "no";
        writeable = "yes";
        "force user" = "username";
        "fruit:aapl" = "yes";
        "fruit:time machine" = "yes";
        "vfs objects" = "catia fruit streams_xattr";
    };
  };
}

Printer sharing

The `samba` packages comes without cups support compiled in, however `sambaFull` features printer sharing support. To use it set the `services.samba.package` option:

services.samba.package = pkgs.sambaFull;

A printer share that allows all members in the local network printing could look like this:

{ pkgs, ... }: {
  services.samba = {
    enable = true;
    package = pkgs.sambaFull;
    extraConfig = ''
      load printers = yes
      printing = cups
      printcap name = cups
    '';
    shares = {
      printers = {
        comment = "All Printers";
        path = "/var/spool/samba";
        public = "yes";
        browseable = "yes";
        # to allow user 'guest account' to print.
        "guest ok" = "yes";
        writable = "no";
        printable = "yes";
        "create mode" = 0700;
      };
  };
  systemd.tmpfiles.rules = [
    "d /var/spool/samba 1777 root root -"
  ];
}

links