{ config, lib, pkgs, ... }:
with lib;
{
options = {
services.nullmailer = {
enable = mkOption {
type = types.bool;
default = false;
description = "Whether to enable nullmailer daemon.";
};
user = mkOption {
type = types.str;
default = "nullmailer";
description = ''
User to use to run nullmailer-send.
'';
};
group = mkOption {
type = types.str;
default = "nullmailer";
description = ''
Group to use to run nullmailer-send.
'';
};
setSendmail = mkOption {
type = types.bool;
default = true;
description = "Whether to set the system sendmail to nullmailer's.";
};
remotesFile = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Path to the remotes
control file. This file contains a
list of remote servers to which to send each message.
See man 8 nullmailer-send
for syntax and available
options.
'';
};
config = {
adminaddr = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
If set, all recipients to users at either "localhost" (the literal string)
or the canonical host name (from the me control attribute) are remapped to this address.
This is provided to allow local daemons to be able to send email to
"somebody@localhost" and have it go somewhere sensible instead of being bounced
by your relay host. To send to multiple addresses,
put them all on one line separated by a comma.
'';
};
allmailfrom = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
If set, content will override the envelope sender on all messages.
'';
};
defaultdomain = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The content of this attribute is appended to any host name that
does not contain a period (except localhost), including defaulthost
and idhost. Defaults to the value of the me attribute, if it exists,
otherwise the literal name defauldomain.
'';
};
defaulthost = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The content of this attribute is appended to any address that
is missing a host name. Defaults to the value of the me control
attribute, if it exists, otherwise the literal name defaulthost.
'';
};
doublebounceto = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
If the original sender was empty (the original message was a
delivery status or disposition notification), the double bounce
is sent to the address in this attribute.
'';
};
helohost = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
Sets the environment variable $HELOHOST which is used by the
SMTP protocol module to set the parameter given to the HELO command.
Defaults to the value of the me configuration attribute.
'';
};
idhost = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The content of this attribute is used when building the message-id
string for the message. Defaults to the canonicalized value of defaulthost.
'';
};
maxpause = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The maximum time to pause between successive queue runs, in seconds.
Defaults to 24 hours (86400).
'';
};
me = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The fully-qualifiled host name of the computer running nullmailer.
Defaults to the literal name me.
'';
};
pausetime = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The minimum time to pause between successive queue runs when there
are messages in the queue, in seconds. Defaults to 1 minute (60).
Each time this timeout is reached, the timeout is doubled to a
maximum of maxpause. After new messages are injected, the timeout
is reset. If this is set to 0, nullmailer-send will exit
immediately after going through the queue once (one-shot mode).
'';
};
remotes = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
A list of remote servers to which to send each message. Each line
contains a remote host name or address followed by an optional
protocol string, separated by white space.
See man 8 nullmailer-send
for syntax and available
options.
WARNING: This is stored world-readable in the nix store. If you need
to specify any secret credentials here, consider using the
remotesFile
option instead.
'';
};
sendtimeout = mkOption {
type = types.nullOr types.str;
default = null;
description = ''
The time to wait for a remote module listed above to complete sending
a message before killing it and trying again, in seconds.
Defaults to 1 hour (3600). If this is set to 0, nullmailer-send
will wait forever for messages to complete sending.
'';
};
};
};
};
config = let
cfg = config.services.nullmailer;
in mkIf cfg.enable {
assertions = [
{ assertion = cfg.config.remotes == null || cfg.remotesFile == null;
message = "Only one of `remotesFile` or `config.remotes` may be used at a time.";
}
];
environment = {
systemPackages = [ pkgs.nullmailer ];
etc = let
validAttrs = filterAttrs (name: value: value != null) cfg.config;
in
(foldl' (as: name: as // { "nullmailer/${name}".text = validAttrs.${name}; }) {} (attrNames validAttrs))
// optionalAttrs (cfg.remotesFile != null) { "nullmailer/remotes".source = cfg.remotesFile; };
};
users = {
users.${cfg.user} = {
description = "Nullmailer relay-only mta user";
group = cfg.group;
};
groups.${cfg.group} = { };
};
systemd.tmpfiles.rules = [
"d /var/spool/nullmailer - ${cfg.user} - - -"
];
systemd.services.nullmailer = {
description = "nullmailer";
wantedBy = [ "multi-user.target" ];
after = [ "network.target" ];
preStart = ''
mkdir -p /var/spool/nullmailer/{queue,tmp}
rm -f /var/spool/nullmailer/trigger && mkfifo -m 660 /var/spool/nullmailer/trigger
'';
serviceConfig = {
User = cfg.user;
Group = cfg.group;
ExecStart = "${pkgs.nullmailer}/bin/nullmailer-send";
Restart = "always";
};
};
services.mail.sendmailSetuidWrapper = mkIf cfg.setSendmail {
program = "sendmail";
source = "${pkgs.nullmailer}/bin/sendmail";
owner = cfg.user;
group = cfg.group;
setuid = true;
setgid = true;
};
};
}