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, ...]]:
 
@@ -268,7 +272,7 @@ def _dot_postgresql_path(filename) -> typing.Optional[pathlib.Path]:
 
 
 def _parse_connect_dsn_and_args(*, dsn, host, port, user,
-                                password, passfile, database, ssl,
+                                password, passfile, database, ssl, service,
                                 direct_tls, server_settings,
                                 target_session_attrs, krbsrvname, gsslib):
     # `auth_hosts` is the version of host information for the purposes
@@ -281,6 +285,28 @@ 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 = 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 +341,7 @@ 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 +428,108 @@ 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:
+                    sslcert = service_params.pop('sslcert')
+
+                if 'sslkey' in service_params:
+                    sslkey = service_params.pop('sslkey')
+
+                if 'sslrootcert' in service_params:
+                    sslrootcert = service_params.pop('sslrootcert')
+
+                if 'sslnegotiation' in service_params:
+                    sslnegotiation = service_params.pop('sslnegotiation')
+
+                if 'sslcrl' in service_params:
+                    sslcrl = service_params.pop('sslcrl')
+
+                if 'sslpassword' in service_params:
+                    sslpassword = service_params.pop('sslpassword')
+
+                if 'ssl_min_protocol_version' in service_params:
+                    ssl_min_protocol_version = service_params.pop(
+                        'ssl_min_protocol_version'
+                    )
+
+                if 'ssl_max_protocol_version' in service_params:
+                    ssl_max_protocol_version = service_params.pop(
+                        'ssl_max_protocol_version'
+                    )
+
+                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 +842,8 @@ 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):
     local_vars = locals()
     for var_name in {'max_cacheable_statement_size',
                      'max_cached_statement_lifetime',
@@ -754,7 +873,7 @@ 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)
 
     config = _ClientConfiguration(
         command_timeout=command_timeout,

asyncpg/connection.py

@@ -2074,6 +2074,7 @@ async def _do_execute(
 async def connect(dsn=None, *,
                   host=None, port=None,
                   user=None, password=None, passfile=None,
+                  service=None,
                   database=None,
                   loop=None,
                   timeout=60,
@@ -2183,6 +2184,10 @@ 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 loop:
         An asyncio event loop instance.  If ``None``, the default
         event loop will be used.
@@ -2428,6 +2433,7 @@ async def connect(dsn=None, *,
             user=user,
             password=password,
             passfile=passfile,
+            service=service,
             ssl=ssl,
             direct_tls=direct_tls,
             database=database,

tests/test_connect.py

@@ -1116,7 +1116,8 @@ def run_testcase(self, testcase):
         env = testcase.get('env', {})
         test_env = {'PGHOST': None, 'PGPORT': None,
                     'PGUSER': None, 'PGPASSWORD': None,
-                    'PGDATABASE': None, 'PGSSLMODE': None}
+                    'PGDATABASE': None, 'PGSSLMODE': None,
+                    'PGSERVICE': None, }
         test_env.update(env)
 
         dsn = testcase.get('dsn')
@@ -1132,6 +1133,7 @@ def run_testcase(self, testcase):
         target_session_attrs = testcase.get('target_session_attrs')
         krbsrvname = testcase.get('krbsrvname')
         gsslib = testcase.get('gsslib')
+        service = testcase.get('service')
 
         expected = testcase.get('result')
         expected_error = testcase.get('error')
@@ -1157,7 +1159,7 @@ def run_testcase(self, testcase):
                 direct_tls=direct_tls,
                 server_settings=server_settings,
                 target_session_attrs=target_session_attrs,
-                krbsrvname=krbsrvname, gsslib=gsslib)
+                krbsrvname=krbsrvname, gsslib=gsslib, service=service)
 
             params = {
                 k: v for k, v in params._asdict().items()
@@ -1236,6 +1238,111 @@ def test_connect_params(self):
         for testcase in self.TESTS:
             self.run_testcase(testcase)
 
+    def test_connect_connection_service_file(self):
+        connection_service_file = tempfile.NamedTemporaryFile(
+            'w+t', delete=False)
+        connection_service_file.write(textwrap.dedent('''
+[test_service_dbname]
+port=5433
+host=somehost
+dbname=test_dbname
+user=admin
+password=test_password
+target_session_attrs=primary
+krbsrvname=fakekrbsrvname
+gsslib=sspi
+
+[test_service_database]
+port=5433
+host=somehost
+database=test_dbname
+user=admin
+password=test_password
+target_session_attrs=primary
+krbsrvname=fakekrbsrvname
+gsslib=sspi
+        '''))
+        connection_service_file.close()
+        os.chmod(connection_service_file.name, stat.S_IWUSR | stat.S_IRUSR)
+        try:
+            # Test connection service file with dbname
+            self.run_testcase({
+                'dsn': 'postgresql://?service=test_service_dbname',
+                'env': {
+                    'PGSERVICEFILE': connection_service_file.name
+                },
+                'result': (
+                    [('somehost', 5433)],
+                    {
+                        'user': 'admin',
+                        'password': 'test_password',
+                        'database': 'test_dbname',
+                        'target_session_attrs': 'primary',
+                        'krbsrvname': 'fakekrbsrvname',
+                        'gsslib': 'sspi',
+                    }
+                )
+            })
+            # Test connection service file with database
+            self.run_testcase({
+                'dsn': 'postgresql://?service=test_service_database',
+                'env': {
+                    'PGSERVICEFILE': connection_service_file.name
+                },
+                'result': (
+                    [('somehost', 5433)],
+                    {
+                        'user': 'admin',
+                        'password': 'test_password',
+                        'database': 'test_dbname',
+                        'target_session_attrs': 'primary',
+                        'krbsrvname': 'fakekrbsrvname',
+                        'gsslib': 'sspi',
+                    }
+                )
+            })
+            # Test that envvars are overridden by service file
+            self.run_testcase({
+                'dsn': 'postgresql://?service=test_service_dbname',
+                'env': {
+                    'PGUSER': 'user',
+                    'PGSERVICEFILE': connection_service_file.name
+                },
+                'result': (
+                    [('somehost', 5433)],
+                    {
+                        'user': 'admin',
+                        'password': 'test_password',
+                        'database': 'test_dbname',
+                        'target_session_attrs': 'primary',
+                        'krbsrvname': 'fakekrbsrvname',
+                        'gsslib': 'sspi',
+                    }
+                )
+            })
+            # Test that dsn params overwrite service file
+            self.run_testcase({
+                'dsn': 'postgresql://?service={}&dbname={}'.format(
+                    "test_service_dbname", "test_dbname_dsn"
+                ),
+                'env': {
+                    'PGSERVICEFILE': connection_service_file.name
+                },
+                'result': (
+                    [('somehost', 5433)],
+                    {
+                        'user': 'admin',
+                        'password': 'test_password',
+                        'database': 'test_dbname_dsn',
+                        'target_session_attrs': 'primary',
+                        'krbsrvname': 'fakekrbsrvname',
+                        'gsslib': 'sspi',
+                    }
+                )
+            })
+        finally:
+            os.unlink(connection_service_file.name)
+
     def test_connect_pgpass_regular(self):
         passfile = tempfile.NamedTemporaryFile('w+t', delete=False)
         passfile.write(textwrap.dedent(R'''