Compatibility with latest changes in urlparse (#3275)

It doesn't accept multiple hosts with [] character in URL anymore.
To mitigate the problem we switch to native wrappers of
PQconninfoParse() function from libpq when it is possible and use own
implementation only when psycopg2 is too old.

patroni/postgresql/config.py

@@ -17,6 +17,7 @@ from ..dcs import Leader, Member, RemoteMember, slot_name_from_member_name
 from ..exceptions import PatroniFatalException, PostgresConnectionException
 from ..file_perm import pg_perm
 from ..postgresql.misc import get_major_from_minor_version, postgres_version_to_int
+from ..psycopg import parse_conninfo
 from ..utils import compare_values, get_postgres_version, is_subpath, \
     maybe_convert_from_base_unit, parse_bool, parse_int, split_host_port, uri, validate_directory
 from ..validator import EnumValidator, IntValidator
@@ -30,7 +31,17 @@ logger = logging.getLogger(__name__)
 PARAMETER_RE = re.compile(r'([a-z_]+)\s*=\s*')
 
 
-def conninfo_uri_parse(dsn: str) -> Dict[str, str]:
+def _conninfo_uri_parse(dsn: str) -> Dict[str, str]:
+    """
+    >>> r = _conninfo_uri_parse('postgresql://u%2Fse:pass@:%2f123/db%2Fsdf?application_name=mya%2Fpp&ssl=true')
+    >>> r == {'application_name': 'mya/pp', 'dbname': 'db/sdf', 'sslmode': 'require',\
+              'password': 'pass', 'port': '/123', 'user': 'u/se'}
+    True
+    >>> r = _conninfo_uri_parse('postgresql://u%2Fse:pass@[::1]/db%2Fsdf?application_name=mya%2Fpp&ssl=true')
+    >>> r == {'application_name': 'mya/pp', 'dbname': 'db/sdf', 'host': '::1', 'sslmode': 'require',\
+              'password': 'pass', 'user': 'u/se'}
+    True
+    """
     ret: Dict[str, str] = {}
     r = urlparse(dsn)
     if r.username:
@@ -52,9 +63,9 @@ def conninfo_uri_parse(dsn: str) -> Dict[str, str]:
             host = tmp[0]
         hosts.append(host)
         ports.append(tmp[1] if len(tmp) == 2 else '')
-    if hosts:
+    if any(map(len, hosts)):
         ret['host'] = ','.join(hosts)
-    if ports:
+    if any(map(len, ports)):
         ret['port'] = ','.join(ports)
     ret = {name: unquote(value) for name, value in ret.items()}
     ret.update({name: value for name, value in parse_qsl(r.query)})
@@ -84,7 +95,20 @@ def read_param_value(value: str) -> Union[Tuple[None, None], Tuple[str, int]]:
     return (None, None) if is_quoted else (ret, i)
 
 
-def conninfo_parse(dsn: str) -> Optional[Dict[str, str]]:
+def _conninfo_dsn_parse(dsn: str) -> Optional[Dict[str, str]]:
+    """
+    >>> r = _conninfo_dsn_parse(" host = 'host' dbname = db\\\\ name requiressl=1 ")
+    >>> r == {'dbname': 'db name', 'host': 'host', 'requiressl': '1'}
+    True
+    >>> _conninfo_dsn_parse('requiressl = 0\\\\') == {'requiressl': '0'}
+    True
+    >>> _conninfo_dsn_parse("host=a foo = '") is None
+    True
+    >>> _conninfo_dsn_parse("host=a foo = ") is None
+    True
+    >>> _conninfo_dsn_parse("1") is None
+    True
+    """
     ret: Dict[str, str] = {}
     length = len(dsn)
     i = 0
@@ -111,17 +135,44 @@ def conninfo_parse(dsn: str) -> Optional[Dict[str, str]]:
     return ret
 
 
-def parse_dsn(value: str) -> Optional[Dict[str, str]]:
+def _conninfo_parse(value: str) -> Optional[Dict[str, str]]:
     """
     Very simple equivalent of `psycopg2.extensions.parse_dsn` introduced in 2.7.0.
-    We are not using psycopg2 function in order to remain compatible with 2.5.4+.
-    There are a few minor differences though, this function sets the `sslmode`, 'gssencmode',
-    and `channel_binding` to `prefer` if they are not present in the connection string.
+    Exists just for compatibility with 2.5.4+.
+
+    >>> r = _conninfo_parse('postgresql://foo/postgres')
+    >>> r == {'dbname': 'postgres', 'host': 'foo'}
+    True
+    >>> r = _conninfo_parse(" host = 'host' dbname = db\\\\ name requiressl=1 ")
+    >>> r == {'dbname': 'db name', 'host': 'host', 'sslmode': 'require'}
+    True
+    >>> _conninfo_parse('requiressl = 0\\\\') == {'sslmode': 'prefer'}
+    True
+    """
+
+    if value.startswith('postgres://') or value.startswith('postgresql://'):
+        ret = _conninfo_uri_parse(value)
+    else:
+        ret = _conninfo_dsn_parse(value)
+
+    if ret and 'sslmode' not in ret:  # allow sslmode to take precedence over requiressl
+        requiressl = ret.pop('requiressl', None)
+        if requiressl == '1':
+            ret['sslmode'] = 'require'
+        elif requiressl is not None:
+            ret['sslmode'] = 'prefer'
+    return ret
+
+
+def parse_dsn(value: str) -> Optional[Dict[str, str]]:
+    """
+    Compatibility layer on top of function from psycopg2/psycopg3, which parses connection strings.
+    In this function sets the `sslmode`, 'gssencmode', and `channel_binding` to `prefer`
+    and `sslnegotiation` to `postgres` if they are not present in the connection string.
     This is necessary to simplify comparison of the old and the new values.
 
-    >>> r = parse_dsn('postgresql://u%2Fse:pass@:%2f123,[::1]/db%2Fsdf?application_name=mya%2Fpp&ssl=true')
-    >>> r == {'application_name': 'mya/pp', 'dbname': 'db/sdf', 'host': ',::1', 'sslmode': 'require',\
-              'password': 'pass', 'port': '/123,', 'user': 'u/se', 'gssencmode': 'prefer',\
+    >>> r = parse_dsn('postgresql://foo/postgres')
+    >>> r == {'dbname': 'postgres', 'host': 'foo', 'sslmode': 'prefer', 'gssencmode': 'prefer',\
               'channel_binding': 'prefer', 'sslnegotiation': 'postgres'}
     True
     >>> r = parse_dsn(" host = 'host' dbname = db\\\\ name requiressl=1 ")
@@ -131,26 +182,14 @@ def parse_dsn(value: str) -> Optional[Dict[str, str]]:
     >>> parse_dsn('requiressl = 0\\\\') == {'sslmode': 'prefer', 'gssencmode': 'prefer',\
                                             'channel_binding': 'prefer', 'sslnegotiation': 'postgres'}
     True
-    >>> parse_dsn("host=a foo = '") is None
-    True
-    >>> parse_dsn("host=a foo = ") is None
-    True
-    >>> parse_dsn("1") is None
+    >>> parse_dsn('foo=bar') == {'foo': 'bar', 'sslmode': 'prefer', 'gssencmode': 'prefer',\
+                                 'channel_binding': 'prefer', 'sslnegotiation': 'postgres'}
     True
     """
-    if value.startswith('postgres://') or value.startswith('postgresql://'):
-        ret = conninfo_uri_parse(value)
-    else:
-        ret = conninfo_parse(value)
+    ret = parse_conninfo(value, _conninfo_parse)
 
     if ret:
-        if 'sslmode' not in ret:  # allow sslmode to take precedence over requiressl
-            requiressl = ret.pop('requiressl', None)
-            if requiressl == '1':
-                ret['sslmode'] = 'require'
-            elif requiressl is not None:
-                ret['sslmode'] = 'prefer'
-            ret.setdefault('sslmode', 'prefer')
+        ret.setdefault('sslmode', 'prefer')
         ret.setdefault('gssencmode', 'prefer')
         ret.setdefault('channel_binding', 'prefer')
         ret.setdefault('sslnegotiation', 'postgres')

patroni/psycopg.py

@@ -4,13 +4,14 @@ This module is able to handle both :mod:`pyscopg2` and :mod:`psycopg`, and it ex
 :mod:`psycopg2` takes precedence. :mod:`psycopg` will only be used if :mod:`psycopg2` is either absent or older than
 ``2.5.4``.
 """
-from typing import Any, Optional, TYPE_CHECKING, Union
+from typing import Any, Callable, Dict, Optional, TYPE_CHECKING, Union
 
 if TYPE_CHECKING:  # pragma: no cover
     from psycopg import Connection
     from psycopg2 import connection, cursor
 
-__all__ = ['connect', 'quote_ident', 'quote_literal', 'DatabaseError', 'Error', 'OperationalError', 'ProgrammingError']
+__all__ = ['connect', 'parse_conninfo', 'quote_ident', 'quote_literal',
+           'DatabaseError', 'Error', 'OperationalError', 'ProgrammingError']
 
 _legacy = False
 try:
@@ -23,10 +24,21 @@ try:
     from psycopg2.extensions import adapt
 
     try:
-        from psycopg2.extensions import quote_ident as _quote_ident
+        from psycopg2.extensions import parse_dsn, quote_ident as _quote_ident
+
+        def _parse_conninfo(conninfo: str, **kwargs: Any) -> Any:
+            """Wraps :func:`parse_dsn` function.
+
+            Exists only to please pyright.
+            """
+            return parse_dsn(conninfo)
     except ImportError:
         _legacy = True
 
+        def _parse_conninfo(conninfo: str, **kwargs: Any) -> Any:
+            """Return ``None`` and rely on fallback."""
+            return None
+
     def quote_literal(value: Any, conn: Optional[Any] = None) -> str:
         """Quote *value* as a SQL literal.
 
@@ -49,6 +61,7 @@ except ImportError:
     from psycopg import DatabaseError, Error, OperationalError, ProgrammingError, sql
     # isort: off
     from psycopg import connect as __connect  # pyright: ignore [reportUnknownVariableType]
+    from psycopg.conninfo import conninfo_to_dict as _parse_conninfo
 
     def __get_parameter_status(self: 'Connection[Any]', param_name: str) -> Optional[str]:
         """Helper function to be injected into :class:`Connection` object.
@@ -137,3 +150,18 @@ def quote_ident(value: Any, conn: Optional[Union['cursor', 'connection', 'Connec
     if _legacy or conn is None:
         return '"{0}"'.format(value.replace('"', '""'))
     return _quote_ident(value, conn)
+
+
+def parse_conninfo(value: str, fallback: Callable[[str], Optional[Dict[str, str]]]) -> Optional[Dict[str, str]]:
+    """Parse connection string.
+
+    :param value: value to parse.
+    :param fallback: a function to use if we have only very old ``psycopg2``, which doesn't expose :func:`parse_dsn`.
+
+    :returns: a :class:`dict` object, or ``None`` if failed to parse.
+    """
+    try:
+        ret = _parse_conninfo(value)
+    except Exception:
+        ret = None
+    return ret or fallback(value)