Leon Schuermann 51cdb83674 Support customized maildir type and location per virtual user
This adds the option to add a customized userdb_mail parameter to the
Dovecot userdb, overriding the global mail_location setting. This
change applies to both mail delivery (handled via LMTP from postfix to
Dovecot), as well as Maildir access via IMAP etc. Furthermore, the UID
and GID can be customized to reflect the desired permissions. Finally,
the Dovecot virtual user home, holding the user's private state, can
be set.

These changes allow for great flexibility in the mail server
setup. For instance, users can selectively have their mail accessible
through a Maildir in their home directory, or via a purely virtual
user maintained under /var/vmail.
2025-02-02 09:42:28 -05:00

422 lines
13 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, pkgs, lib, ... }:
with (import ./common.nix { inherit config pkgs lib; });
let
cfg = config.mailserver;
passwdDir = "/run/dovecot2";
passwdFile = "${passwdDir}/passwd";
userdbFile = "${passwdDir}/userdb";
# This file contains the ldap bind password
ldapConfFile = "${passwdDir}/dovecot-ldap.conf.ext";
bool2int = x: if x then "1" else "0";
maildirLayoutAppendix = lib.optionalString cfg.useFsLayout ":LAYOUT=fs";
maildirUTF8FolderNames = lib.optionalString cfg.useUTF8FolderNames ":UTF-8";
# maildir in format "/${domain}/${user}"
dovecotMaildir =
"maildir:${cfg.mailDirectory}/%d/%n${maildirLayoutAppendix}${maildirUTF8FolderNames}"
+ (lib.optionalString (cfg.indexDir != null)
":INDEX=${cfg.indexDir}/%d/%n"
);
postfixCfg = config.services.postfix;
dovecot2Cfg = config.services.dovecot2;
stateDir = "/var/lib/dovecot";
pipeBin = pkgs.stdenv.mkDerivation {
name = "pipe_bin";
src = ./dovecot/pipe_bin;
buildInputs = with pkgs; [ makeWrapper coreutils bash rspamd ];
buildCommand = ''
mkdir -p $out/pipe/bin
cp $src/* $out/pipe/bin/
chmod a+x $out/pipe/bin/*
patchShebangs $out/pipe/bin
for file in $out/pipe/bin/*; do
wrapProgram $file \
--set PATH "${pkgs.coreutils}/bin:${pkgs.rspamd}/bin"
done
'';
};
ldapConfig = pkgs.writeTextFile {
name = "dovecot-ldap.conf.ext.template";
text = ''
ldap_version = 3
uris = ${lib.concatStringsSep " " cfg.ldap.uris}
${lib.optionalString cfg.ldap.startTls ''
tls = yes
''}
tls_require_cert = hard
tls_ca_cert_file = ${cfg.ldap.tlsCAFile}
dn = ${cfg.ldap.bind.dn}
sasl_bind = no
auth_bind = yes
base = ${cfg.ldap.searchBase}
scope = ${mkLdapSearchScope cfg.ldap.searchScope}
${lib.optionalString (cfg.ldap.dovecot.userAttrs != null) ''
user_attrs = ${cfg.ldap.dovecot.userAttrs}
''}
user_filter = ${cfg.ldap.dovecot.userFilter}
${lib.optionalString (cfg.ldap.dovecot.passAttrs != "") ''
pass_attrs = ${cfg.ldap.dovecot.passAttrs}
''}
pass_filter = ${cfg.ldap.dovecot.passFilter}
'';
};
setPwdInLdapConfFile = appendLdapBindPwd {
name = "ldap-conf-file";
file = ldapConfig;
prefix = ''dnpass = "'';
suffix = ''"'';
passwordFile = cfg.ldap.bind.passwordFile;
destination = ldapConfFile;
};
genPasswdScript = pkgs.writeScript "generate-password-file" ''
#!${pkgs.stdenv.shell}
set -euo pipefail
if (! test -d "${passwdDir}"); then
mkdir "${passwdDir}"
chmod 755 "${passwdDir}"
fi
# Prevent world-readable password files, even temporarily.
umask 077
for f in ${builtins.toString (lib.mapAttrsToList (name: value: passwordFiles."${name}") cfg.loginAccounts)}; do
if [ ! -f "$f" ]; then
echo "Expected password hash file $f does not exist!"
exit 1
fi
done
cat <<EOF > ${passwdFile}
${lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value:
"${name}:${"$(head -n 1 ${passwordFiles."${name}"})"}::::::"
) cfg.loginAccounts)}
EOF
cat <<EOF > ${userdbFile}
${lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value: (
if value.customMaildir == null then (
"${name}:::::::"
) else (
"${name}:"
+ ":${builtins.toString value.customMaildir.uid}"
+ ":${builtins.toString value.customMaildir.gid}"
+ ":"
+ ":${value.customMaildir.dovecotHome}"
+ ":/run/current-system/sw/bin/nologin"
+ ":userdb_mail=${value.customMaildir.mailDirectorySpec}"
)
) + (
if lib.isString value.quota then
" userdb_quota_rule=*:storage=${value.quota}"
else
""
)) cfg.loginAccounts)}
EOF
'';
junkMailboxes = builtins.attrNames (lib.filterAttrs (n: v: v ? "specialUse" && v.specialUse == "Junk") cfg.mailboxes);
junkMailboxNumber = builtins.length junkMailboxes;
# The assertion garantees there is exactly one Junk mailbox.
junkMailboxName = if junkMailboxNumber == 1 then builtins.elemAt junkMailboxes 0 else "";
mkLdapSearchScope = scope: (
if scope == "sub" then "subtree"
else if scope == "one" then "onelevel"
else scope
);
in
{
config = with cfg; lib.mkIf enable {
assertions = [
{
assertion = junkMailboxNumber == 1;
message = "nixos-mailserver requires exactly one dovecot mailbox with the 'special use' flag set to 'Junk' (${builtins.toString junkMailboxNumber} have been found)";
}
];
# for sieve-test. Shelling it in on demand usually doesnt' work, as it reads
# the global config and tries to open shared libraries configured in there,
# which are usually not compatible.
environment.systemPackages = [
pkgs.dovecot_pigeonhole
];
services.dovecot2 = {
enable = true;
enableImap = enableImap || enableImapSsl;
enablePop3 = enablePop3 || enablePop3Ssl;
enablePAM = false;
enableQuota = true;
mailGroup = vmailGroupName;
mailUser = vmailUserName;
mailLocation = dovecotMaildir;
sslServerCert = certificatePath;
sslServerKey = keyPath;
enableLmtp = true;
modules = [ pkgs.dovecot_pigeonhole ] ++ (lib.optional cfg.fullTextSearch.enable pkgs.dovecot_fts_xapian );
mailPlugins.globally.enable = lib.optionals cfg.fullTextSearch.enable [ "fts" "fts_xapian" ];
protocols = lib.optional cfg.enableManageSieve "sieve";
pluginSettings = {
sieve = "file:${cfg.sieveDirectory}/%u/scripts;active=${cfg.sieveDirectory}/%u/active.sieve";
sieve_default = "file:${cfg.sieveDirectory}/%u/default.sieve";
sieve_default_name = "default";
};
sieve = {
extensions = [
"fileinto"
];
scripts.after = builtins.toFile "spam.sieve" ''
require "fileinto";
if header :is "X-Spam" "Yes" {
fileinto "${junkMailboxName}";
stop;
}
'';
pipeBins = map lib.getExe [
(pkgs.writeShellScriptBin "sa-learn-ham.sh"
"exec ${pkgs.rspamd}/bin/rspamc -h /run/rspamd/worker-controller.sock learn_ham")
(pkgs.writeShellScriptBin "sa-learn-spam.sh"
"exec ${pkgs.rspamd}/bin/rspamc -h /run/rspamd/worker-controller.sock learn_spam")
];
};
imapsieve.mailbox = [
{
name = junkMailboxName;
causes = [ "COPY" "APPEND" ];
before = ./dovecot/imap_sieve/report-spam.sieve;
}
{
name = "*";
from = junkMailboxName;
causes = [ "COPY" ];
before = ./dovecot/imap_sieve/report-ham.sieve;
}
];
mailboxes = cfg.mailboxes;
extraConfig = ''
#Extra Config
${lib.optionalString debug ''
mail_debug = yes
auth_debug = yes
verbose_ssl = yes
''}
${lib.optionalString (cfg.enableImap || cfg.enableImapSsl) ''
service imap-login {
inet_listener imap {
${if cfg.enableImap then ''
port = 143
'' else ''
# see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
port = 0
''}
}
inet_listener imaps {
${if cfg.enableImapSsl then ''
port = 993
ssl = yes
'' else ''
# see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
port = 0
''}
}
}
''}
${lib.optionalString (cfg.enablePop3 || cfg.enablePop3Ssl) ''
service pop3-login {
inet_listener pop3 {
${if cfg.enablePop3 then ''
port = 110
'' else ''
# see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
port = 0
''}
}
inet_listener pop3s {
${if cfg.enablePop3Ssl then ''
port = 995
ssl = yes
'' else ''
# see https://dovecot.org/pipermail/dovecot/2010-March/047479.html
port = 0
''}
}
}
''}
protocol imap {
mail_max_userip_connections = ${toString cfg.maxConnectionsPerUser}
mail_plugins = $mail_plugins imap_sieve
}
service imap {
vsz_limit = ${builtins.toString cfg.imapMemoryLimit} MB
}
protocol pop3 {
mail_max_userip_connections = ${toString cfg.maxConnectionsPerUser}
}
mail_access_groups = ${vmailGroupName}
ssl = required
ssl_min_protocol = TLSv1.2
ssl_prefer_server_ciphers = yes
service lmtp {
unix_listener dovecot-lmtp {
group = ${postfixCfg.group}
mode = 0600
user = ${postfixCfg.user}
}
vsz_limit = ${builtins.toString cfg.lmtpMemoryLimit} MB
}
service quota-status {
vsz_limit = ${builtins.toString cfg.quotaStatusMemoryLimit} MB
}
recipient_delimiter = ${cfg.recipientDelimiter}
lmtp_save_to_detail_mailbox = ${cfg.lmtpSaveToDetailMailbox}
protocol lmtp {
mail_plugins = $mail_plugins sieve
}
passdb {
driver = passwd-file
args = ${passwdFile}
}
userdb {
driver = passwd-file
args = ${userdbFile}
default_fields = uid=${builtins.toString cfg.vmailUID} gid=${builtins.toString cfg.vmailUID} home=${cfg.mailDirectory}
}
${lib.optionalString cfg.ldap.enable ''
passdb {
driver = ldap
args = ${ldapConfFile}
}
userdb {
driver = ldap
args = ${ldapConfFile}
default_fields = home=/var/vmail/ldap/%u uid=${toString cfg.vmailUID} gid=${toString cfg.vmailUID}
}
''}
service auth {
unix_listener auth {
mode = 0660
user = ${postfixCfg.user}
group = ${postfixCfg.group}
}
}
auth_mechanisms = plain login
namespace inbox {
separator = ${cfg.hierarchySeparator}
inbox = yes
}
${lib.optionalString cfg.fullTextSearch.enable ''
plugin {
plugin = fts fts_xapian
fts = xapian
fts_xapian = partial=${toString cfg.fullTextSearch.minSize} verbose=${bool2int cfg.debug}
fts_autoindex = ${if cfg.fullTextSearch.autoIndex then "yes" else "no"}
${lib.strings.concatImapStringsSep "\n" (n: x: "fts_autoindex_exclude${if n==1 then "" else toString n} = ${x}") cfg.fullTextSearch.autoIndexExclude}
fts_enforced = ${cfg.fullTextSearch.enforced}
}
service indexer-worker {
${lib.optionalString (cfg.fullTextSearch.memoryLimit != null) ''
vsz_limit = ${toString (cfg.fullTextSearch.memoryLimit*1024*1024)}
''}
process_limit = 0
}
''}
lda_mailbox_autosubscribe = yes
lda_mailbox_autocreate = yes
'';
};
systemd.services.dovecot2 = {
preStart = ''
${genPasswdScript}
'' + (lib.optionalString cfg.ldap.enable setPwdInLdapConfFile);
};
systemd.services.postfix.restartTriggers = [ genPasswdScript ] ++ (lib.optional cfg.ldap.enable [setPwdInLdapConfFile]);
systemd.services.dovecot-fts-xapian-optimize = lib.mkIf (cfg.fullTextSearch.enable && cfg.fullTextSearch.maintenance.enable) {
description = "Optimize dovecot indices for fts_xapian";
requisite = [ "dovecot2.service" ];
after = [ "dovecot2.service" ];
startAt = cfg.fullTextSearch.maintenance.onCalendar;
serviceConfig = {
Type = "oneshot";
ExecStart = "${pkgs.dovecot}/bin/doveadm fts optimize -A";
PrivateDevices = true;
PrivateNetwork = true;
ProtectKernelTunables = true;
ProtectKernelModules = true;
ProtectControlGroups = true;
ProtectHome = true;
ProtectSystem = true;
PrivateTmp = true;
};
};
systemd.timers.dovecot-fts-xapian-optimize = lib.mkIf (cfg.fullTextSearch.enable && cfg.fullTextSearch.maintenance.enable && cfg.fullTextSearch.maintenance.randomizedDelaySec != 0) {
timerConfig = {
RandomizedDelaySec = cfg.fullTextSearch.maintenance.randomizedDelaySec;
};
};
};
}