postfix: forwarding emails of login accounts with keeping local copy

When a local account address is forwarded, the mails were not locally
kept. This was due to the way lookup tables were internally managed.

Instead of using lists to represent Postfix lookup tables, we now use
attribute sets: they can then be easily merged.

A regression test for
https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/issues/
has been added: it sets a forward on a local address and ensure an
email sent to this address is locally kept.

Fixes #205
This commit is contained in:
Antoine Eiche 2021-01-28 23:58:08 +01:00 committed by lewo
parent 17eec31cae
commit 5f431207b3
3 changed files with 122 additions and 54 deletions

View file

@ -22,25 +22,48 @@ let
inherit (lib.strings) concatStringsSep;
cfg = config.mailserver;
# valiases_postfix :: [ String ]
valiases_postfix = lib.flatten (lib.mapAttrsToList
# Merge several lookup tables. A lookup table is a attribute set where
# - the key is an address (user@example.com) or a domain (@example.com)
# - the value is a list of addresses
mergeLookupTables = tables: lib.zipAttrsWith (n: v: lib.flatten v) tables;
# valiases_postfix :: Map String [String]
valiases_postfix = mergeLookupTables (lib.flatten (lib.mapAttrsToList
(name: value:
let to = name;
in map (from: "${from} ${to}") (value.aliases ++ lib.singleton name))
cfg.loginAccounts);
in map (from: {"${from}" = to;}) (value.aliases ++ lib.singleton name))
cfg.loginAccounts));
# catchAllPostfix :: [ String ]
catchAllPostfix = lib.flatten (lib.mapAttrsToList
# catchAllPostfix :: Map String [String]
catchAllPostfix = mergeLookupTables (lib.flatten (lib.mapAttrsToList
(name: value:
let to = name;
in map (from: "@${from} ${to}") value.catchAll)
cfg.loginAccounts);
in map (from: {"@${from}" = to;}) value.catchAll)
cfg.loginAccounts));
# extra_valiases_postfix :: [ String ]
extra_valiases_postfix = attrsToAliasList cfg.extraVirtualAliases;
# all_valiases_postfix :: Map String [String]
all_valiases_postfix = mergeLookupTables [valiases_postfix extra_valiases_postfix];
# all_valiases_postfix :: [ String ]
all_valiases_postfix = valiases_postfix ++ extra_valiases_postfix;
# attrsToLookupTable :: Map String (Either String [ String ]) -> Map String [String]
attrsToLookupTable = aliases: let
lookupTables = lib.mapAttrsToList (from: to: {"${from}" = to;}) aliases;
in mergeLookupTables lookupTables;
# extra_valiases_postfix :: Map String [String]
extra_valiases_postfix = attrsToLookupTable cfg.extraVirtualAliases;
# forwards :: Map String [String]
forwards = attrsToLookupTable cfg.forwards;
# lookupTableToString :: Map String [String] -> String
lookupTableToString = attrs: let
valueToString = value: lib.concatStringsSep ", " value;
in lib.concatStringsSep "\n" (lib.mapAttrsToList (name: value: "${name} ${valueToString value}") attrs);
# valiases_file :: Path
valiases_file = let
content = lookupTableToString (mergeLookupTables [all_valiases_postfix catchAllPostfix]);
in builtins.toFile "valias" content;
# denied_recipients_postfix :: [ String ]
denied_recipients_postfix = (map
@ -48,29 +71,12 @@ let
(lib.filter (acct: acct.sendOnly) (lib.attrValues cfg.loginAccounts)));
denied_recipients_file = builtins.toFile "denied_recipients" (lib.concatStringsSep "\n" denied_recipients_postfix);
# attrsToAliasList :: Map String (Either String [ String ]) -> [ String ]
attrsToAliasList = aliases:
let
toList = to: if builtins.isList to then to else [to];
in lib.mapAttrsToList
(from: to: "${from} " + (lib.concatStringsSep ", " (toList to)))
aliases;
# forwards :: [ String ]
forwards = attrsToAliasList cfg.forwards;
# valiases_file :: Path
valiases_file = builtins.toFile "valias"
(lib.concatStringsSep "\n" (all_valiases_postfix ++
catchAllPostfix));
reject_senders_postfix = (map
(sender:
"${sender} REJECT")
(cfg.rejectSender));
reject_senders_file = builtins.toFile "reject_senders" (lib.concatStringsSep "\n" (reject_senders_postfix)) ;
reject_recipients_postfix = (map
(recipient:
"${recipient} REJECT")
@ -87,7 +93,7 @@ let
# for details on how this file looks. By using the same file as valiases,
# every alias is owned (uniquely) by its user.
# The user's own address is already in all_valiases_postfix.
vaccounts_file = builtins.toFile "vaccounts" (lib.concatStringsSep "\n" all_valiases_postfix);
vaccounts_file = builtins.toFile "vaccounts" (lookupTableToString all_valiases_postfix);
submissionHeaderCleanupRules = pkgs.writeText "submission_header_cleanup_rules" (''
# Removes sensitive headers from mails handed in via the submission port.
@ -149,8 +155,7 @@ in
sslKey = keyPath;
enableSubmission = cfg.enableSubmission;
enableSubmissions = cfg.enableSubmissionSsl;
virtual =
(lib.concatStringsSep "\n" (all_valiases_postfix ++ catchAllPostfix ++ forwards));
virtual = lookupTableToString (mergeLookupTables [all_valiases_postfix catchAllPostfix forwards]);
config = {
# Extra Config

View file

@ -24,28 +24,36 @@ def _send_mail(smtp_host, smtp_port, from_addr, from_pwd, to_addr, subject, star
retry = RETRY
while True:
with smtplib.SMTP(smtp_host, port=smtp_port) as smtp:
if starttls:
smtp.starttls()
if from_pwd is not None:
smtp.login(from_addr, from_pwd)
try:
smtp.sendmail(from_addr, [to_addr], message)
return
except smtplib.SMTPResponseException as e:
# This is a service unavailable error
# In this situation, we want to retry.
if e.smtp_code == 451:
if retry > 0:
retry = retry - 1
time.sleep(1)
continue
try:
with smtplib.SMTP(smtp_host, port=smtp_port) as smtp:
try:
if starttls:
smtp.starttls()
if from_pwd is not None:
smtp.login(from_addr, from_pwd)
smtp.sendmail(from_addr, [to_addr], message)
return
except smtplib.SMTPResponseException as e:
if e.smtp_code == 451: # service unavailable error
print(e)
elif e.smtp_code == 454: # smtplib.SMTPResponseException: (454, b'4.3.0 Try again later')
print(e)
else:
print("Error while sending mail: %s" % e)
exit(5)
except Exception as e:
print("Error while sending mail: %s" % e)
exit(4)
raise
except OSError as e:
if e.errno in [16, -2]:
print("OSError exception message: ", e)
else:
raise
if retry > 0:
retry = retry - 1
time.sleep(1)
print("Retrying")
else:
print("Retry attempts exhausted")
exit(5)
def _read_mail(
imap_host,

View file

@ -33,6 +33,8 @@ let
htpasswd -nbB "" "${password}" | cut -d: -f2 > $out
'';
hashedPasswordFile = hashPassword "my-password";
passwordFile = pkgs.writeText "password" "my-password";
in
pkgs.nixosTest {
name = "intern";
@ -45,20 +47,34 @@ pkgs.nixosTest {
virtualisation.memorySize = 1024;
environment.systemPackages = [
(pkgs.writeScriptBin "mail-check" ''
${pkgs.python3}/bin/python ${../scripts/mail-check.py} $@
'')];
mailserver = {
enable = true;
fqdn = "mail.example.com";
domains = [ "example.com" ];
localDnsResolver = false;
loginAccounts = {
"user1@example.com" = {
hashedPassword = "$6$/z4n8AQl6K$kiOkBTWlZfBd7PvF5GsJ8PmPgdZsFGN1jPGZufxxr60PoR0oUsrvzm2oQiflyz5ir9fFJ.d/zKm/NgLXNUsNX/";
hashedPasswordFile = hashedPasswordFile;
};
"user2@example.com" = {
hashedPasswordFile = hashedPasswordFile;
};
"send-only@example.com" = {
hashedPasswordFile = hashPassword "send-only";
sendOnly = true;
};
};
forwards = {
# user2@example.com is a local account and its mails are
# also forwarded to user1@example.com
"user2@example.com" = "user1@example.com";
};
vmailGroupName = "vmail";
vmailUID = 5000;
@ -71,6 +87,45 @@ pkgs.nixosTest {
machine.start()
machine.wait_for_unit("multi-user.target")
# Regression test for https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/issues/205
with subtest("mail forwarded can are locally kept"):
# A mail sent to user2@example.com is in the user1@example.com mailbox
machine.succeed(
" ".join(
[
"mail-check send-and-read",
"--smtp-port 587",
"--smtp-starttls",
"--smtp-host localhost",
"--imap-host localhost",
"--imap-username user1@example.com",
"--from-addr user1@example.com",
"--to-addr user2@example.com",
"--src-password-file ${passwordFile}",
"--dst-password-file ${passwordFile}",
"--ignore-dkim-spf",
]
)
)
# A mail sent to user2@example.com is in the user2@example.com mailbox
machine.succeed(
" ".join(
[
"mail-check send-and-read",
"--smtp-port 587",
"--smtp-starttls",
"--smtp-host localhost",
"--imap-host localhost",
"--imap-username user2@example.com",
"--from-addr user1@example.com",
"--to-addr user2@example.com",
"--src-password-file ${passwordFile}",
"--dst-password-file ${passwordFile}",
"--ignore-dkim-spf",
]
)
)
with subtest("vmail gid is set correctly"):
machine.succeed("getent group vmail | grep 5000")