Implement connection service file functionality

asyncpg/connect_utils.py

@@ -7,6 +7,7 @@
 from __future__ import annotations
 
 import asyncio
+import configparser
 import collections
 from collections.abc import Callable
 import enum
@@ -87,6 +88,9 @@ class SSLNegotiation(compat.StrEnum):
     PGPASSFILE = '.pgpass'
 
 
+PG_SERVICEFILE = '.pg_service.conf'
+
+
 def _read_password_file(passfile: pathlib.Path) \
         -> typing.List[typing.Tuple[str, ...]]:
 
@@ -269,6 +273,7 @@ def _dot_postgresql_path(filename) -> typing.Optional[pathlib.Path]:
 
 def _parse_connect_dsn_and_args(*, dsn, host, port, user,
                                 password, passfile, database, ssl,
+                                service, servicefile,
                                 direct_tls, server_settings,
                                 target_session_attrs, krbsrvname, gsslib):
     # `auth_hosts` is the version of host information for the purposes
@@ -281,6 +286,32 @@ def _parse_connect_dsn_and_args(*, dsn, host, port, user,
     if dsn:
         parsed = urllib.parse.urlparse(dsn)
 
+        query = None
+        if parsed.query:
+            query = urllib.parse.parse_qs(parsed.query, strict_parsing=True)
+            for key, val in query.items():
+                if isinstance(val, list):
+                    query[key] = val[-1]
+
+            if 'service' in query:
+                val = query.pop('service')
+                if not service and val:
+                    service = val
+
+        connection_service_file = servicefile
+
+        if connection_service_file is None:
+            connection_service_file = os.getenv('PGSERVICEFILE')
+
+        if connection_service_file is None:
+            homedir = compat.get_pg_home_directory()
+            if homedir:
+                connection_service_file = homedir / PG_SERVICEFILE
+            else:
+                connection_service_file = None
+        else:
+            connection_service_file = pathlib.Path(connection_service_file)
+
         if parsed.scheme not in {'postgresql', 'postgres'}:
             raise exceptions.ClientConfigurationError(
                 'invalid DSN: scheme is expected to be either '
@@ -315,11 +346,7 @@ def _parse_connect_dsn_and_args(*, dsn, host, port, user,
         if password is None and dsn_password:
             password = urllib.parse.unquote(dsn_password)
 
-        if parsed.query:
-            query = urllib.parse.parse_qs(parsed.query, strict_parsing=True)
-            for key, val in query.items():
-                if isinstance(val, list):
-                    query[key] = val[-1]
+        if query:
 
             if 'port' in query:
                 val = query.pop('port')
@@ -406,12 +433,124 @@ def _parse_connect_dsn_and_args(*, dsn, host, port, user,
                 if gsslib is None:
                     gsslib = val
 
+            if 'service' in query:
+                val = query.pop('service')
+                if service is None:
+                    service = val
+
             if query:
                 if server_settings is None:
                     server_settings = query
                 else:
                     server_settings = {**query, **server_settings}
 
+        if connection_service_file is not None and service is not None:
+            pg_service = configparser.ConfigParser()
+            pg_service.read(connection_service_file)
+            if service in pg_service.sections():
+                service_params = pg_service[service]
+                if 'port' in service_params:
+                    val = service_params.pop('port')
+                    if not port and val:
+                        port = [int(p) for p in val.split(',')]
+
+                if 'host' in service_params:
+                    val = service_params.pop('host')
+                    if not host and val:
+                        host, port = _parse_hostlist(val, port)
+
+                if 'dbname' in service_params:
+                    val = service_params.pop('dbname')
+                    if database is None:
+                        database = val
+
+                if 'database' in service_params:
+                    val = service_params.pop('database')
+                    if database is None:
+                        database = val
+
+                if 'user' in service_params:
+                    val = service_params.pop('user')
+                    if user is None:
+                        user = val
+
+                if 'password' in service_params:
+                    val = service_params.pop('password')
+                    if password is None:
+                        password = val
+
+                if 'passfile' in service_params:
+                    val = service_params.pop('passfile')
+                    if passfile is None:
+                        passfile = val
+
+                if 'sslmode' in service_params:
+                    val = service_params.pop('sslmode')
+                    if ssl is None:
+                        ssl = val
+
+                if 'sslcert' in service_params:
+                    val = service_params.pop('sslcert')
+                    if sslcert is None:
+                        sslcert = val
+
+                if 'sslkey' in service_params:
+                    val = service_params.pop('sslkey')
+                    if sslkey is None:
+                        sslkey = val
+
+                if 'sslrootcert' in service_params:
+                    val = service_params.pop('sslrootcert')
+                    if sslrootcert is None:
+                        sslrootcert = val
+
+                if 'sslnegotiation' in service_params:
+                    val = service_params.pop('sslnegotiation')
+                    if sslnegotiation is None:
+                        sslnegotiation = val
+
+                if 'sslcrl' in service_params:
+                    val = service_params.pop('sslcrl')
+                    if sslcrl is None:
+                        sslcrl = val
+
+                if 'sslpassword' in service_params:
+                    val = service_params.pop('sslpassword')
+                    if sslpassword is None:
+                        sslpassword = val
+
+                if 'ssl_min_protocol_version' in service_params:
+                    val = service_params.pop(
+                        'ssl_min_protocol_version'
+                    )
+                    if ssl_min_protocol_version is None:
+                        ssl_min_protocol_version = val
+
+                if 'ssl_max_protocol_version' in service_params:
+                    val = service_params.pop(
+                        'ssl_max_protocol_version'
+                    )
+                    if ssl_max_protocol_version is None:
+                        ssl_max_protocol_version = val
+
+                if 'target_session_attrs' in service_params:
+                    dsn_target_session_attrs = service_params.pop(
+                        'target_session_attrs'
+                    )
+                    if target_session_attrs is None:
+                        target_session_attrs = dsn_target_session_attrs
+
+                if 'krbsrvname' in service_params:
+                    val = service_params.pop('krbsrvname')
+                    if krbsrvname is None:
+                        krbsrvname = val
+
+                if 'gsslib' in service_params:
+                    val = service_params.pop('gsslib')
+                    if gsslib is None:
+                        gsslib = val
+    if not service:
+        service = os.environ.get('PGSERVICE')
     if not host:
         hostspec = os.environ.get('PGHOST')
         if hostspec:
@@ -724,7 +863,8 @@ def _parse_connect_arguments(*, dsn, host, port, user, password, passfile,
                              max_cached_statement_lifetime,
                              max_cacheable_statement_size,
                              ssl, direct_tls, server_settings,
-                             target_session_attrs, krbsrvname, gsslib):
+                             target_session_attrs, krbsrvname, gsslib,
+                             service, servicefile):
     local_vars = locals()
     for var_name in {'max_cacheable_statement_size',
                      'max_cached_statement_lifetime',
@@ -754,7 +894,8 @@ def _parse_connect_arguments(*, dsn, host, port, user, password, passfile,
         direct_tls=direct_tls, database=database,
         server_settings=server_settings,
         target_session_attrs=target_session_attrs,
-        krbsrvname=krbsrvname, gsslib=gsslib)
+        krbsrvname=krbsrvname, gsslib=gsslib,
+        service=service, servicefile=servicefile)
 
     config = _ClientConfiguration(
         command_timeout=command_timeout,

asyncpg/connection.py

@@ -2074,6 +2074,8 @@ async def _do_execute(
 async def connect(dsn=None, *,
                   host=None, port=None,
                   user=None, password=None, passfile=None,
+                  service=None,
+                  servicefile=None,
                   database=None,
                   loop=None,
                   timeout=60,
@@ -2183,6 +2185,14 @@ async def connect(dsn=None, *,
         (defaults to ``~/.pgpass``, or ``%APPDATA%\postgresql\pgpass.conf``
         on Windows).
 
+    :param service:
+        The name of the postgres connection service stored in the postgres
+        connection service file.
+
+    :param servicefile:
+        The location of the connnection service file used to store
+        connection parameters.
+
     :param loop:
         An asyncio event loop instance.  If ``None``, the default
         event loop will be used.
@@ -2395,6 +2405,9 @@ async def connect(dsn=None, *,
     .. versionchanged:: 0.30.0
        Added the *krbsrvname* and *gsslib* parameters.
 
+    .. versionchanged:: 0.31.0
+       Added the *servicefile* and *service* parameters.
+
     .. _SSLContext: https://docs.python.org/3/library/ssl.html#ssl.SSLContext
     .. _create_default_context:
         https://docs.python.org/3/library/ssl.html#ssl.create_default_context
@@ -2428,6 +2441,8 @@ async def connect(dsn=None, *,
             user=user,
             password=password,
             passfile=passfile,
+            service=service,
+            servicefile=servicefile,
             ssl=ssl,
             direct_tls=direct_tls,
             database=database,