Add support for clientinfo

Changelog entry:

* Tell the server more about the connecting client: hostname,
  application name, pymonetdb version, process id and an optional remark.
  This information will show up in the `sys.sessions` table.
  Configurable with the new settings `client_info`, `client_application`
  and `client_remark`.

CHANGES.md

@@ -2,6 +2,12 @@
 
 changes since 1.8.1
 
+* Tell the server more about the connecting client: hostname,
+  application name, pymonetdb version, process id and an optional remark.
+  This information will show up in the `sys.sessions` table.
+  Configurable with the new settings `client_info`, `client_application`
+  and `client_remark`.
+
 
 # 1.8.1
 

pymonetdb/__init__.py

@@ -10,6 +10,10 @@
 #
 # Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
 
+# Set __version__ first, so the imported modules can access it.
+__version__ = '1.8.2a0'
+
+
 from typing import Optional
 from pymonetdb import sql
 from pymonetdb import mapi
@@ -26,7 +30,6 @@
 from pymonetdb.filetransfer.directoryhandler import SafeDirectoryHandler
 from pymonetdb.target import Target, looks_like_url
 
-__version__ = '1.8.2a0'
 
 apilevel = "2.0"
 threadsafety = 1
@@ -65,6 +68,9 @@ def connect(    # noqa C901
         clientcert: Optional[str] = None,
         schema: Optional[str] = None,
         timezone: Optional[int] = None,
+        client_info: Optional[bool] = None,
+        client_application: Optional[str] = None,
+        client_remark: Optional[str] = None,
         dangerous_tls_nocheck: Optional[str] = None,
 ):
     """Set up a connection to a MonetDB SQL database
@@ -121,6 +127,12 @@ def connect(    # noqa C901
         the schema to select after connecting
     timezone : int
         the time zone to use, in minutes east of UTC
+    client_info : bool
+        whether to send client details when connecting
+    client_application : str
+        application name to send in the  client details
+    client_remark : str
+        additional info to send in the  client details
     dangerous_tls_nocheck : str
         comma-separated list of TLS certificate checks to skip during connecting:
         'host': ignore host name mismatch,
@@ -171,6 +183,12 @@ def connect(    # noqa C901
         target.schema = schema
     if timezone is not None:
         target.timezone = timezone
+    if client_info is not None:
+        target.client_info = client_info
+    if client_application is not None:
+        target.client_application = client_application
+    if client_remark is not None:
+        target.client_remark = client_remark
     if dangerous_tls_nocheck is not None:
         target.dangerous_tls_nocheck = dangerous_tls_nocheck
 

pymonetdb/mapi.py

@@ -9,18 +9,22 @@
 
 
 import os
+import platform
 import re
 import socket
 import logging
 import struct
 import hashlib
 import ssl
+import sys
 import typing
-from typing import Callable, List, Optional, Tuple, Union
+from typing import Callable, Dict, List, Optional, Tuple, Union
 
+# import pymonetdb
 from pymonetdb.exceptions import OperationalError, DatabaseError, \
     ProgrammingError, NotSupportedError, IntegrityError
 from pymonetdb.target import Target
+from pymonetdb import __version__
 
 if typing.TYPE_CHECKING:
     from pymonetdb.filetransfer.downloads import Downloader
@@ -98,6 +102,7 @@ class Connection(object):
     is_raw_control: Optional[bool] = None
     handshake_options_callback: Optional[Callable[[int], List['HandshakeOption']]] = None
     remaining_handshake_options: List['HandshakeOption'] = []
+    clientinfo: Optional[Dict[str, Optional[str]]] = None
     uploader: Optional['Uploader'] = None
     downloader: Optional['Downloader'] = None
     stashed_buffer: Optional[bytearray] = None
@@ -154,6 +159,18 @@ def connect(self, database: Optional[Union[Target, str]] = None, *args, **kwargs
         # handle during the handshake
         self.state = STATE_READY
 
+        if self.clientinfo:
+            info = "".join(
+                f"{k}={v or ''}\n"
+                for k, v in self.clientinfo.items()
+                if v is None or '\n' not in v
+            )
+            if info:
+                try:
+                    self.cmd(f"Xclientinfo {info}")
+                except OperationalError as e:
+                    logger.warn(f"Server rejected clientinfo: {e}")
+
         for opt in self.remaining_handshake_options:
             opt.fallback(opt.value)
 
@@ -578,6 +595,21 @@ def _challenge_response(self, challenge: str):  # noqa: C901
             assert part.startswith('BINARY=')
             self.binexport_level = int(part[7:])
 
+        if len(challenges) >= 10:
+            part = challenges[9]
+            assert part == "CLIENTINFO"
+            if self.target.client_info:
+                application_name = self.target.client_application
+                if not application_name and sys.argv:
+                    application_name = os.path.basename(sys.argv[0])
+                self.clientinfo = dict(
+                    ClientHostName=platform.node() or None,
+                    ApplicationName=application_name or None,
+                    ClientLibrary=f"pymonetdb {__version__}",
+                    ClientRemark=self.target.client_remark or None,
+                    ClientPid=str(os.getpid()),
+                )
+
         callback = self.handshake_options_callback
         handshake_options = callback(self.binexport_level) if callback else []
 

pymonetdb/target.py

@@ -29,8 +29,9 @@ def looks_like_url(text: str) -> bool:
     'sock', 'sockdir', 'sockprefix', 'cert', 'certhash', 'clientkey', 'clientcert',
     'user', 'password', 'language', 'autocommit', 'schema', 'timezone',
     'binary', 'replysize', 'fetchsize', 'maxprefetch',
-    'connect_timeout']
-)
+    'connect_timeout',
+    'client_info', 'client_application', 'client_remark',
+])
 IGNORED = set(['hash', 'debug', 'logfile'])
 VIRTUAL = set([
     'connect_scan', 'connect_sockdir',
@@ -73,6 +74,9 @@ def looks_like_url(text: str) -> bool:
     fetchsize=None,
     maxprefetch=None,
     connect_timeout=0,
+    client_info=True,
+    client_application="",
+    client_remark="",
     dangerous_tls_nocheck="",
 )
 
@@ -172,6 +176,9 @@ def clone(self):
                          'rows beyond this limit are retrieved on demand, <1 means unlimited')
     maxprefetch = urlparam('maxprefetch', 'integer', 'specific to pymonetdb')
     connect_timeout = urlparam('connect_timeout', 'integer', 'abort if connect takes longer than this')
+    client_info = urlparam('client_info', 'bool', 'whether to send client details when connecting')
+    client_application = urlparam('client_application', 'string', 'application name to send in client details')
+    client_remark = urlparam('client_remark', 'string', 'application name to send in client details')
     dangerous_tls_nocheck = urlparam(
         'dangerous_tls_nocheck', 'bool',
         'comma separated certificate checks to skip, host: do not verify host, cert: do not verify certificate chain')

tests/test_clientinfo.py

@@ -0,0 +1,73 @@
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0.  If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+#
+# Copyright 1997 - July 2008 CWI, August 2008 - 2016 MonetDB B.V.
+
+from unittest import TestCase, skipUnless
+import pymonetdb
+
+from tests.util import have_monetdb_version_at_least, test_url
+
+QUERY = """\
+SELECT language, peer, hostname, application, client, clientpid, remark
+FROM sys.sessions
+WHERE sessionid = sys.current_sessionid()
+"""
+
+SERVER_HAS_CLIENTINFO = have_monetdb_version_at_least(11, 51, 0)
+
+
+@skipUnless(SERVER_HAS_CLIENTINFO, "server does not support clientinfo")
+class TestClientInfo(TestCase):
+
+    def get_clientinfo(self, **connect_args):
+        with pymonetdb.connect(test_url, **connect_args) as conn, conn.cursor() as c:
+            nrows = c.execute(QUERY)
+            self.assertEqual(nrows, 1)
+            row = c.fetchone()
+            d = dict(
+                (descr.name, v) for descr, v in zip(c.description, row)
+            )
+            return d
+
+    # 'application': 'python3 -m unittest'
+    # 'client': 'pymonetdb 1.8.2a0'
+    # 'clientpid': 2762097
+    # 'hostname': 'totoro'
+    # 'language': 'sql'
+    # 'peer': '<UNIX SOCKET>'
+    # 'remark': None
+
+    def test_default_clientinfo(self):
+        d = self.get_clientinfo()
+        self.assertEqual(d['language'], 'sql')
+        self.assertIsNotNone(d['peer'])
+        self.assertIsNotNone(d['hostname'])
+        self.assertIsNotNone(d['application'])
+        self.assertIn('pymonetdb', d['client'])
+        self.assertIn(pymonetdb.__version__, d['client'])
+        self.assertGreater(d['clientpid'], 0)
+        self.assertIsNone(d['remark'])
+
+    def test_suppressed_clientinfo(self):
+        d = self.get_clientinfo(client_info=False)
+        self.assertEqual(d['language'], 'sql')
+        self.assertIsNotNone(d['peer'])
+        self.assertIsNone(d['hostname'])
+        self.assertIsNone(d['application'])
+        self.assertIsNone(d['client'])
+        self.assertIsNone(d['clientpid'])
+        self.assertIsNone(d['remark'])
+
+    def test_set_application_name(self):
+        d = self.get_clientinfo(client_application='banana')
+        self.assertEqual(d['application'], 'banana')
+        d = self.get_clientinfo(client_info=False, client_application='banana')
+        self.assertIsNone(d['application'])
+
+    def test_set_remark(self):
+        d = self.get_clientinfo(client_remark='banana')
+        self.assertEqual(d['remark'], 'banana')
+        d = self.get_clientinfo(client_info=False, client_remark='banana')
+        self.assertIsNone(d['remark'])