feat: support setup with only an IPv4 address, but no domain

.github/workflows/ci-no-dns.yaml

@@ -0,0 +1,35 @@
+name: No-DNS
+
+on:
+  # Triggers when a PR is merged into main or a direct push occurs
+  push:
+    branches: [ "main" ]
+
+  # Triggers for any PR (and its subsequent commits) targeting the main branch
+  pull_request:
+    branches: [ "main" ]
+
+# Newest push wins: Prevents multiple runs from clashing and wasting runner efforts
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number || github.ref }}
+  cancel-in-progress: true
+
+
+jobs:
+  no-dns:
+    name: LXC deploy and test
+    uses: chatmail/cmlxc/.github/workflows/lxc-test.yml@d39fe34c39cee6d760c3479325e8dc82b66a8928
+    with:
+      cmlxc_commands: |
+        cmlxc init 
+        # single cmdeploy relay test
+        cmlxc -v deploy-cmdeploy --source ./repo --ipv4-only --no-dns cm0
+        cmlxc -v test-cmdeploy --no-dns cm0
+
+        # cross cmdeploy relay test
+        cmlxc -v deploy-cmdeploy --source ./repo cm1
+        cmlxc -v test-cmdeploy --no-dns cm0 cm1
+
+        # cross cmdeploy/madmail relay tests
+        cmlxc -v deploy-madmail mad0
+        cmlxc -v test-cmdeploy --no-dns cm0 mad0

.github/workflows/ci.yaml

@@ -1,4 +1,4 @@
-name: Run unit-tests and container-based deploy+test verification
+name: CI
 
 on:
   # Triggers when a PR is merged into main or a direct push occurs
@@ -57,7 +57,7 @@ jobs:
 
   lxc-test:
     name: LXC deploy and test
-    uses: chatmail/cmlxc/.github/workflows/lxc-test.yml@v0.10.0
+    uses: chatmail/cmlxc/.github/workflows/lxc-test.yml@d39fe34c39cee6d760c3479325e8dc82b66a8928
     with:
       cmlxc_commands: |
         cmlxc init 

chatmaild/pyproject.toml

@@ -10,6 +10,7 @@ dependencies = [
   "filelock",
   "requests",
   "crypt-r >= 3.13.1 ; python_version >= '3.11'",
+  "domain-validator",
 ]
 
 [tool.setuptools]

chatmaild/src/chatmaild/config.py

@@ -1,6 +1,8 @@
+import ipaddress
 from pathlib import Path
 
 import iniconfig
+from domain_validator import DomainValidator
 
 from chatmaild.user import User
 
@@ -20,6 +22,8 @@ class Config:
     def __init__(self, inipath, params):
         self._inipath = inipath
         self.mail_domain = params["mail_domain"]
+        self.mail_domain_hostname = format_arpa_address(params["mail_domain"])
+        self.mail_domain_deliverable = format_deliverable_domain(params["mail_domain"])
         self.max_user_send_per_minute = int(params.get("max_user_send_per_minute", 60))
         self.max_user_send_burst_size = int(params.get("max_user_send_burst_size", 10))
         self.max_mailbox_size = params["max_mailbox_size"]
@@ -79,7 +83,7 @@ def __init__(self, inipath, params):
                 )
             self.tls_cert_mode = "external"
             self.tls_cert_path, self.tls_key_path = parts
-        elif self.mail_domain.startswith("_"):
+        elif self.mail_domain.startswith("_") or is_valid_ipv4(params["mail_domain"]):
             self.tls_cert_mode = "self"
             self.tls_cert_path = "/etc/ssl/certs/mailserver.pem"
             self.tls_key_path = "/etc/ssl/private/mailserver.key"
@@ -89,7 +93,9 @@ def __init__(self, inipath, params):
             self.tls_key_path = f"/var/lib/acme/live/{self.mail_domain}/privkey"
 
         # deprecated option
-        mbdir = params.get("mailboxes_dir", f"/home/vmail/mail/{self.mail_domain}")
+        mbdir = params.get(
+            "mailboxes_dir", f"/home/vmail/mail/{self.mail_domain_deliverable}"
+        )
         self.mailboxes_dir = Path(mbdir.strip())
 
         # old unused option (except for first migration from sqlite to maildir store)
@@ -175,3 +181,26 @@ def get_default_config_content(mail_domain, **overrides):
                 lines.append(line)
         content = "\n".join(lines)
     return content
+
+
+def is_valid_ipv4(address: str) -> bool:
+    """Check if a mail_domain is an IPv4 address."""
+    try:
+        ipaddress.IPv4Address(address)
+        return True
+    except ValueError:
+        return False
+
+
+def format_arpa_address(address: str) -> str:
+    if is_valid_ipv4(address):
+        return ipaddress.IPv4Address(address).reverse_pointer
+    DomainValidator().validate_domain_re(address)
+    return address
+
+
+def format_deliverable_domain(mail_domain: str) -> str:
+    if is_valid_ipv4(mail_domain):
+        return f"[{mail_domain}]"
+    DomainValidator().validate_domain_re(mail_domain)
+    return mail_domain

chatmaild/src/chatmaild/doveauth.py

@@ -108,15 +108,15 @@ def handle_lookup(self, parts):
         if namespace == "shared":
             if type == "userdb":
                 user = args[0]
-                if user.endswith(f"@{config.mail_domain}"):
+                if user.endswith(f"@{config.mail_domain_deliverable}"):
                     res = self.lookup_userdb(user)
                 if res:
                     reply_command = "O"
                 else:
                     reply_command = "N"
             elif type == "passdb":
                 user = args[1]
-                if user.endswith(f"@{config.mail_domain}"):
+                if user.endswith(f"@{config.mail_domain_deliverable}"):
                     res = self.lookup_passdb(user, cleartext_password=args[0])
                 if res:
                     reply_command = "O"

chatmaild/src/chatmaild/newemail.py

@@ -2,7 +2,6 @@
 
 """CGI script for creating new accounts."""
 
-import ipaddress
 import json
 import secrets
 import string
@@ -15,16 +14,6 @@
 ALPHANUMERIC_PUNCT = string.ascii_letters + string.digits + string.punctuation
 
 
-def wrap_ip(host):
-    if host.startswith("[") and host.endswith("]"):
-        return host
-    try:
-        ipaddress.ip_address(host)
-        return f"[{host}]"
-    except ValueError:
-        return host
-
-
 def create_newemail_dict(config: Config):
     user = "".join(
         secrets.choice(ALPHANUMERIC) for _ in range(config.username_max_length)
@@ -33,16 +22,24 @@ def create_newemail_dict(config: Config):
         secrets.choice(ALPHANUMERIC_PUNCT)
         for _ in range(config.password_min_length + 3)
     )
-    return dict(email=f"{user}@{wrap_ip(config.mail_domain)}", password=f"{password}")
+    return dict(
+        email=f"{user}@{config.mail_domain_deliverable}", password=f"{password}"
+    )
 
 
-def create_dclogin_url(email, password):
+def create_dclogin_url(config, email, password):
     """Build a dclogin: URL with credentials and self-signed cert acceptance.
 
     Uses ic=3 (AcceptInvalidCertificates) so chatmail clients
     can connect to servers with self-signed TLS certificates.
     """
-    return f"dclogin:{quote(email, safe='@')}?p={quote(password, safe='')}&v=1&ic=3"
+    if config.mail_domain != config.mail_domain_deliverable:
+        imap_host = "&ih=" + config.mail_domain
+        smtp_host = "&sh=" + config.mail_domain
+    else:
+        imap_host = ""
+        smtp_host = ""
+    return f"dclogin:{quote(email, safe='@[]')}?p={quote(password, safe='')}&v=1{imap_host}{smtp_host}&ic=3"
 
 
 def print_new_account():
@@ -51,7 +48,9 @@ def print_new_account():
 
     result = dict(email=creds["email"], password=creds["password"])
     if config.tls_cert_mode == "self":
-        result["dclogin_url"] = create_dclogin_url(creds["email"], creds["password"])
+        result["dclogin_url"] = create_dclogin_url(
+            config, creds["email"], creds["password"]
+        )
 
     print("Content-Type: application/json")
     print("")

chatmaild/src/chatmaild/tests/plugin.py

@@ -31,6 +31,11 @@ def example_config(make_config):
     return make_config("chat.example.org")
 
 
+@pytest.fixture
+def ipv4_config(make_config):
+    return make_config("1.3.3.7")
+
+
 @pytest.fixture
 def maildomain(example_config):
     return example_config.mail_domain

chatmaild/src/chatmaild/tests/test_config.py

@@ -1,6 +1,14 @@
+from contextlib import nullcontext as does_not_raise
+
 import pytest
 
-from chatmaild.config import parse_size_mb, read_config
+from chatmaild.config import (
+    format_arpa_address,
+    format_deliverable_domain,
+    is_valid_ipv4,
+    parse_size_mb,
+    read_config,
+)
 
 
 def test_read_config_basic(example_config):
@@ -13,6 +21,12 @@ def test_read_config_basic(example_config):
     example_config = read_config(inipath)
     assert example_config.max_user_send_per_minute == 37
     assert example_config.mail_domain == "chat.example.org"
+    assert example_config.mail_domain_deliverable == "chat.example.org"
+
+
+def test_read_config_deliverable(ipv4_config):
+    assert ipv4_config.mail_domain == "1.3.3.7"
+    assert ipv4_config.mail_domain_deliverable == "[1.3.3.7]"
 
 
 def test_read_config_basic_using_defaults(tmp_path, maildomain):
@@ -135,3 +149,45 @@ def test_max_mailbox_size_mb(make_config):
     config = make_config("chat.example.org")
     assert config.max_mailbox_size == "500M"
     assert config.max_mailbox_size_mb == 500
+
+
+@pytest.mark.parametrize(
+    ["input", "result"],
+    [
+        ("example.org", False),
+        ("1.3.3.7", True),
+        ("fe::1", False),
+        ("ad.1e.dag.adf", False),
+        ("12394142", False),
+    ],
+)
+def test_is_valid_ipv4(input, result):
+    assert result == is_valid_ipv4(input)
+
+
+@pytest.mark.parametrize(
+    ["input", "result", "exception"],
+    [
+        ("example.org", "example.org", does_not_raise()),
+        ("1.3.3.7", "7.3.3.1.in-addr.arpa", does_not_raise()),
+        ("fe::1", None, pytest.raises(ValueError)),
+        ("12394142", None, pytest.raises(ValueError)),
+    ],
+)
+def test_format_arpa_address(input, result, exception):
+    with exception:
+        assert result == format_arpa_address(input)
+
+
+@pytest.mark.parametrize(
+    ["input", "result", "exception"],
+    [
+        ("example.org", "example.org", does_not_raise()),
+        ("1.3.3.7", "[1.3.3.7]", does_not_raise()),
+        ("fe::1", None, pytest.raises(ValueError)),
+        ("12394142", None, pytest.raises(ValueError)),
+    ],
+)
+def test_format_deliverable_domain(input, result, exception):
+    with exception:
+        assert result == format_deliverable_domain(input)

chatmaild/src/chatmaild/tests/test_doveauth.py

@@ -44,12 +44,20 @@ def test_invalid_username_length(example_config):
     config.username_min_length = 6
     config.username_max_length = 10
     password = create_newemail_dict(config)["password"]
-    assert not is_allowed_to_create(config, f"a1234@{config.mail_domain}", password)
-    assert is_allowed_to_create(config, f"012345@{config.mail_domain}", password)
-    assert is_allowed_to_create(config, f"0123456@{config.mail_domain}", password)
-    assert is_allowed_to_create(config, f"0123456789@{config.mail_domain}", password)
     assert not is_allowed_to_create(
-        config, f"0123456789x@{config.mail_domain}", password
+        config, f"a1234@{config.mail_domain_deliverable}", password
+    )
+    assert is_allowed_to_create(
+        config, f"012345@{config.mail_domain_deliverable}", password
+    )
+    assert is_allowed_to_create(
+        config, f"0123456@{config.mail_domain_deliverable}", password
+    )
+    assert is_allowed_to_create(
+        config, f"0123456789@{config.mail_domain_deliverable}", password
+    )
+    assert not is_allowed_to_create(
+        config, f"0123456789x@{config.mail_domain_deliverable}", password
     )
 
 
@@ -124,7 +132,7 @@ def test_invalid_localpart_characters(make_config):
     """Test that is_allowed_to_create rejects localparts with invalid characters."""
     config = make_config("chat.example.org", {"username_min_length": "3"})
     password = "zequ0Aimuchoodaechik"
-    domain = config.mail_domain
+    domain = config.mail_domain_deliverable
 
     # valid localparts
     assert is_allowed_to_create(config, f"abc123@{domain}", password)

chatmaild/src/chatmaild/tests/test_filtermail_blackbox.py

@@ -74,7 +74,7 @@ def test_one_mail(
         print(line.decode("ascii"), file=sys.stderr)
         pytest.fail("starting filtermail failed")
 
-    addr = f"user1@{config.mail_domain}"
+    addr = f"user1@{config.mail_domain_deliverable}"
     config.get_user(addr).set_password("l1k2j3l1k2j3l")
 
     # send encrypted mail

chatmaild/src/chatmaild/tests/test_newmail.py

@@ -19,24 +19,35 @@ def test_create_newemail_dict(example_config):
     assert ac1["password"] != ac2["password"]
 
 
-def test_create_newemail_dict_ip(make_config):
-    config = make_config("1.2.3.4")
-    ac = create_newemail_dict(config)
-    assert ac["email"].endswith("@[1.2.3.4]")
+def test_create_newemail_dict_ip(ipv4_config):
+    ac = create_newemail_dict(ipv4_config)
+    assert ac["email"].endswith("@[1.3.3.7]")
 
 
-def test_create_dclogin_url():
-    url = create_dclogin_url("user@example.org", "p@ss w+rd")
+def test_create_dclogin_url(example_config):
+    addr = "user@example.org"
+    password = "p@ss w+rd"
+    url = create_dclogin_url(example_config, addr, password)
     assert url.startswith("dclogin:")
     assert "v=1" in url
     assert "ic=3" in url
 
-    assert "user@example.org" in url
+    assert addr in url
     # password special chars must be encoded
     assert "p%40ss" in url
     assert "w%2Brd" in url
 
 
+def test_create_dclogin_url_ipv4(ipv4_config):
+    addr = "user@[1.3.3.7]"
+    password = "p@ss w+rd"
+    url = create_dclogin_url(ipv4_config, addr, password)
+    assert url.startswith("dclogin:")
+    assert "v=1" in url
+    assert "ic=3" in url
+    assert addr in url
+
+
 def test_print_new_account(capsys, monkeypatch, maildomain, tmpdir, example_config):
     monkeypatch.setattr(chatmaild.newemail, "CONFIG_PATH", str(example_config._inipath))
     print_new_account()
@@ -45,7 +56,7 @@ def test_print_new_account(capsys, monkeypatch, maildomain, tmpdir, example_conf
     assert lines[0] == "Content-Type: application/json"
     assert not lines[1]
     dic = json.loads(lines[2])
-    assert dic["email"].endswith(f"@{example_config.mail_domain}")
+    assert dic["email"].endswith(f"@{example_config.mail_domain_deliverable}")
     assert len(dic["password"]) >= 10
     # default tls_cert=acme should not include dclogin_url
     assert "dclogin_url" not in dic