nixos-mailserver/default.nix

507 lines
15 KiB
Nix

# nixos-mailserver: a simple mail server
# Copyright (C) 2016-2018 Robin Raymond
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>
{ config, lib, pkgs, ... }:
with lib;
let
cfg = config.mailserver;
in
{
options.mailserver = {
enable = mkEnableOption "nixos-mailserver";
fqdn = mkOption {
type = types.str;
example = "mx.example.com";
description = "The fully qualified domain name of the mail server.";
};
domains = mkOption {
type = types.listOf types.str;
example = [ "example.com" ];
default = [];
description = "The domains that this mail server serves.";
};
loginAccounts = mkOption {
type = types.loaOf (types.submodule ({ name, ... }: {
options = {
name = mkOption {
type = types.str;
example = "user1@example.com";
description = "Username";
};
hashedPassword = mkOption {
type = types.str;
example = "$6$evQJs5CFQyPAW09S$Cn99Y8.QjZ2IBnSu4qf1vBxDRWkaIZWOtmu1Ddsm3.H3CFpeVc0JU4llIq8HQXgeatvYhh5O33eWG3TSpjzu6/";
description = ''
Hashed password. Use `mkpasswd` as follows
```
mkpasswd -m sha-512 "super secret password"
```
'';
};
aliases = mkOption {
type = with types; listOf types.str;
example = ["abuse@example.com" "postmaster@example.com"];
default = [];
description = ''
A list of aliases of this login account.
'';
};
catchAll = mkOption {
type = with types; listOf (enum cfg.domains);
example = ["example.com" "example2.com"];
default = [];
description = ''
For which domains should this account act as a catch all?
'';
};
quota = mkOption {
type = with types; nullOr types.str;
default = null;
example = "2G";
description = ''
Per user quota rules. Accepted sizes are `xx k/M/G/T` with the
obvious meaning. Leave blank for the standard quota `100G`.
'';
};
sieveScript = mkOption {
type = with types; nullOr lines;
default = null;
example = ''
require ["fileinto", "mailbox"];
if address :is "from" "notifications@github.com" {
fileinto :create "GitHub";
stop;
}
# This must be the last rule, it will check if list-id is set, and
# file the message into the Lists folder for further investigation
elsif header :matches "list-id" "<?*>" {
fileinto :create "Lists";
stop;
}
'';
description = ''
Per-user sieve script.
'';
};
};
config.name = mkDefault name;
}));
example = {
user1 = {
hashedPassword = "$6$evQJs5CFQyPAW09S$Cn99Y8.QjZ2IBnSu4qf1vBxDRWkaIZWOtmu1Ddsm3.H3CFpeVc0JU4llIq8HQXgeatvYhh5O33eWG3TSpjzu6/";
};
user2 = {
hashedPassword = "$6$oE0ZNv2n7Vk9gOf$9xcZWCCLGdMflIfuA0vR1Q1Xblw6RZqPrP94mEit2/81/7AKj2bqUai5yPyWE.QYPyv6wLMHZvjw3Rlg7yTCD/";
};
};
description = ''
The login account of the domain. Every account is mapped to a unix user,
e.g. `user1@example.com`. To generate the passwords use `mkpasswd` as
follows
```
mkpasswd -m sha-512 "super secret password"
```
'';
default = {};
};
extraVirtualAliases = mkOption {
type = types.attrsOf (types.enum (builtins.attrNames cfg.loginAccounts));
example = {
"info@example.com" = "user1@example.com";
"postmaster@example.com" = "user1@example.com";
"abuse@example.com" = "user1@example.com";
};
description = ''
Virtual Aliases. A virtual alias `"info@example2.com" = "user1@example.com"` means that
all mail to `info@example2.com` is forwarded to `user1@example.com`. Note
that it is expected that `postmaster@example.com` and `abuse@example.com` is
forwarded to some valid email address. (Alternatively you can create login
accounts for `postmaster` and (or) `abuse`). Furthermore, it also allows
the user `user1@example.com` to send emails as `info@example2.com`.
'';
default = {};
};
virtualAliases = mkOption {
type = types.attrsOf (types.enum (builtins.attrNames cfg.loginAccounts));
example = {
"info@example.com" = "user1@example.com";
"postmaster@example.com" = "user1@example.com";
"abuse@example.com" = "user1@example.com";
};
description = ''
Alias for extraVirtualAliases. Deprecated.
'';
default = {};
};
vmailUID = mkOption {
type = types.int;
default = 5000;
description = ''
The unix UID of the virtual mail user. Be mindful that if this is
changed, you will need to manually adjust the permissions of
mailDirectory.
'';
};
vmailUserName = mkOption {
type = types.str;
default = "virtualMail";
description = ''
The user name and group name of the user that owns the directory where all
the mail is stored.
'';
};
vmailGroupName = mkOption {
type = types.str;
default = "virtualMail";
description = ''
The user name and group name of the user that owns the directory where all
the mail is stored.
'';
};
mailDirectory = mkOption {
type = types.path;
default = "/var/vmail";
description = ''
Where to store the mail.
'';
};
useFsLayout = mkOption {
type = types.bool;
default = false;
description = ''
Sets whether dovecot should organize mail in subdirectories:
- /var/vmail/example.com/user/.folder.subfolder/ (default layout)
- /var/vmail/example.com/user/folder/subfolder/ (FS layout)
See https://wiki2.dovecot.org/MailboxFormat/Maildir for details.
'';
};
hierarchySeparator = mkOption {
type = types.string;
default = ".";
description = ''
The hierarchy separator for mailboxes used by dovecot for the namespace 'inbox'.
Dovecot defaults to "." but recommends "/".
This affects how mailboxes appear to mail clients and sieve scripts.
For instance when using "." then in a sieve script "example.com" would refer to the mailbox "com" in the parent mailbox "example".
This does not determine the way your mails are stored on disk.
See https://wiki.dovecot.org/Namespaces for details.
'';
};
mailboxes = mkOption {
description = ''
The mailboxes for dovecot.
Depending on the mail client used it might be necessary to change some mailbox's name.
'';
default = [
{
name = "Trash";
auto = "no";
specialUse = "Trash";
}
{
name = "Junk";
auto = "subscribe";
specialUse = "Junk";
}
{
name = "Drafts";
auto = "subscribe";
specialUse = "Drafts";
}
{
name = "Sent";
auto = "subscribe";
specialUse = "Sent";
}
];
};
certificateScheme = mkOption {
type = types.enum [ 1 2 3 ];
default = 2;
description = ''
Certificate Files. There are three options for these.
1) You specify locations and manually copy certificates there.
2) You let the server create new (self signed) certificates on the fly.
3) You let the server create a certificate via `Let's Encrypt`. Note that
this implies that a stripped down webserver has to be started. This also
implies that the FQDN must be set as an `A` record to point to the IP of
the server. In particular port 80 on the server will be opened. For details
on how to set up the domain records, see the guide in the readme.
'';
};
certificateFile = mkOption {
type = types.path;
example = "/root/mail-server.crt";
description = ''
Scheme 1)
Location of the certificate
'';
};
keyFile = mkOption {
type = types.path;
example = "/root/mail-server.key";
description = ''
Scheme 1)
Location of the key file
'';
};
certificateDirectory = mkOption {
type = types.path;
default = "/var/certs";
description = ''
Sceme 2)
This is the folder where the certificate will be created. The name is
hardcoded to "cert-<domain>.pem" and "key-<domain>.pem" and the
certificate is valid for 10 years.
'';
};
enableImap = mkOption {
type = types.bool;
default = true;
description = ''
Whether to enable imap / pop3. Both variants are only supported in the
(sane) startTLS configuration. The ports are
110 - Pop3
143 - IMAP
587 - SMTP with login
'';
};
enableImapSsl = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable IMAPS, setting this option to true will open port 993
in the firewall.
'';
};
enablePop3 = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable POP3. Both variants are only supported in the (sane)
startTLS configuration. The ports are
110 - Pop3
143 - IMAP
587 - SMTP with login
'';
};
enablePop3Ssl = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable POP3S, setting this option to true will open port 995
in the firewall.
'';
};
enableManageSieve = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable ManageSieve, setting this option to true will open
port 4190 in the firewall.
The ManageSieve protocol allows users to manage their Sieve scripts on
a remote server with a supported client, including Thunderbird.
'';
};
virusScanning = mkOption {
type = types.bool;
default = false;
description = ''
Whether to activate virus scanning. Note that virus scanning is _very_
expensive memory wise.
'';
};
dkimSigning = mkOption {
type = types.bool;
default = true;
description = ''
Whether to activate dkim signing.
'';
};
dkimSelector = mkOption {
type = types.str;
default = "mail";
description = ''
'';
};
dkimKeyDirectory = mkOption {
type = types.path;
default = "/var/dkim";
description = ''
'';
};
dhParamBitLength = mkOption {
type = types.int;
default = 2048;
description =
''
Length of the Diffie Hillman prime used (in bits). It might be a good
idea to set this to 4096 for security purposed, but it will take a _very_
long time to create this prime on startup.
'';
};
debug = mkOption {
type = types.bool;
default = false;
description = ''
Whether to enable verbose logging for mailserver related services. This
intended be used for development purposes only, you probably don't want
to enable this unless you're hacking on nixos-mailserver.
'';
};
localDnsResolver = mkOption {
type = types.bool;
default = true;
description = ''
Runs a local DNS resolver (kresd) as recommended when running rspamd. This prevents your log file from filling up with rspamd_monitored_dns_mon entries.
'';
};
monitoring = {
enable = mkEnableOption "monitoring via monit";
alertAddress = mkOption {
type = types.string;
description = ''
The email address to send alerts to.
'';
};
config = mkOption {
type = types.string;
default = ''
set daemon 120 with start delay 60
set mailserver
localhost
set httpd port 2812 and use address localhost
allow localhost
allow admin:obwjoawijerfoijsiwfj29jf2f2jd
check filesystem root with path /
if space usage > 80% then alert
if inode usage > 80% then alert
check system $HOST
if cpu usage > 95% for 10 cycles then alert
if memory usage > 75% for 5 cycles then alert
if swap usage > 20% for 10 cycles then alert
if loadavg (1min) > 90 for 15 cycles then alert
if loadavg (5min) > 80 for 10 cycles then alert
if loadavg (15min) > 70 for 8 cycles then alert
check process sshd with pidfile /var/run/sshd.pid
start program "${pkgs.systemd}/bin/systemctl start sshd"
stop program "${pkgs.systemd}/bin/systemctl stop sshd"
if failed port 22 protocol ssh for 2 cycles then restart
check process postfix with pidfile /var/lib/postfix/queue/pid/master.pid
start program = "${pkgs.systemd}/bin/systemctl start postfix"
stop program = "${pkgs.systemd}/bin/systemctl stop postfix"
if failed port 25 protocol smtp for 5 cycles then restart
check process dovecot with pidfile /var/run/dovecot2/master.pid
start program = "${pkgs.systemd}/bin/systemctl start dovecot2"
stop program = "${pkgs.systemd}/bin/systemctl stop dovecot2"
if failed host ${cfg.fqdn} port 993 type tcpssl sslauto protocol imap for 5 cycles then restart
check process rspamd with pidfile /var/run/rspamd.pid
start program = "${pkgs.systemd}/bin/systemctl start rspamd"
stop program = "${pkgs.systemd}/bin/systemctl stop rspamd"
'';
description = ''
The configuration used for monitoring via monit.
Use a mail address that you actively check and set it via 'set alert ...'.
'';
};
};
};
imports = [
./mail-server/clamav.nix
./mail-server/monit.nix
./mail-server/users.nix
./mail-server/environment.nix
./mail-server/networking.nix
./mail-server/systemd.nix
./mail-server/dovecot.nix
./mail-server/postfix.nix
./mail-server/rmilter.nix
./mail-server/nginx.nix
./mail-server/kresd.nix
];
config = lib.mkIf config.mailserver.enable {
warnings = if (config.mailserver.virtualAliases != {}) then [ ''
virtualAliases had been derprecated. Use extraVirtualAliases instead or
use the `aliases` field of the loginAccount attribute set
'']
else [];
};
}