feat: add TLS/mTLS support for experimental host

google/cloud/spanner_dbapi/connection.py

@@ -736,6 +736,10 @@ def connect(
     route_to_leader_enabled=True,
     database_role=None,
     experimental_host=None,
+    use_plain_text=False,
+    ca_certificate=None,
+    client_certificate=None,
+    client_key=None,
     **kwargs,
 ):
     """Creates a connection to a Google Cloud Spanner database.
@@ -789,6 +793,28 @@ def connect(
     :rtype: :class:`google.cloud.spanner_dbapi.connection.Connection`
     :returns: Connection object associated with the given Google Cloud Spanner
               resource.
+
+    :type experimental_host: str
+    :param experimental_host: (Optional) The endpoint for a spanner experimental host deployment.
+        This is intended only for experimental host spanner endpoints.
+
+    :type use_plain_text: bool
+    :param use_plain_text: (Optional) Whether to use plain text for the connection.
+        This is intended only for experimental host spanner endpoints.
+        If not set, the default behavior is to use TLS.
+
+    :type ca_certificate: str
+    :param ca_certificate: (Optional) The path to the CA certificate file used for TLS connection.
+        This is intended only for experimental host spanner endpoints.
+        This is mandatory if the experimental_host requires a TLS connection.
+    :type client_certificate: str
+    :param client_certificate: (Optional) The path to the client certificate file used for mTLS connection.
+        This is intended only for experimental host spanner endpoints.
+        This is mandatory if the experimental_host requires an mTLS connection.
+    :type client_key: str
+    :param client_key: (Optional) The path to the client key file used for mTLS connection.
+        This is intended only for experimental host spanner endpoints.
+        This is mandatory if the experimental_host requires an mTLS connection.
     """
     if client is None:
         client_info = ClientInfo(
@@ -817,6 +843,10 @@ def connect(
                 client_info=client_info,
                 route_to_leader_enabled=route_to_leader_enabled,
                 client_options=client_options,
+                use_plain_text=use_plain_text,
+                ca_certificate=ca_certificate,
+                client_certificate=client_certificate,
+                client_key=client_key,
             )
     else:
         if project is not None and client.project != project:

google/cloud/spanner_v1/_helpers.py

@@ -803,3 +803,65 @@ def _merge_Transaction_Options(
 
     # Convert protobuf object back into a TransactionOptions instance
     return TransactionOptions(merged_pb)
+
+
+def _create_experimental_host_transport(
+    transport_factory,
+    experimental_host,
+    use_plain_text,
+    ca_certificate,
+    client_certificate,
+    client_key,
+    interceptors=None,
+):
+    """Creates an experimental host transport for Spanner.
+
+    Args:
+        transport_factory (type): The transport class to instantiate (e.g.
+            `SpannerGrpcTransport`).
+        experimental_host (str): The endpoint for the experimental host.
+        use_plain_text (bool): Whether to use a plain text (insecure) connection.
+        ca_certificate (str): Path to the CA certificate file for TLS.
+        client_certificate (str): Path to the client certificate file for mTLS.
+        client_key (str): Path to the client key file for mTLS.
+        interceptors (list): Optional list of interceptors to add to the channel.
+
+    Returns:
+        object: An instance of the transport class created by `transport_factory`.
+
+    Raises:
+        ValueError: If TLS/mTLS configuration is invalid.
+    """
+    import grpc
+    from google.auth.credentials import AnonymousCredentials
+
+    channel = None
+    if use_plain_text:
+        channel = grpc.insecure_channel(target=experimental_host)
+    elif ca_certificate:
+        with open(ca_certificate, "rb") as f:
+            ca_cert = f.read()
+        if client_certificate and client_key:
+            with open(client_certificate, "rb") as f:
+                client_cert = f.read()
+            with open(client_key, "rb") as f:
+                private_key = f.read()
+            ssl_creds = grpc.ssl_channel_credentials(
+                root_certificates=ca_cert,
+                private_key=private_key,
+                certificate_chain=client_cert,
+            )
+        elif client_certificate or client_key:
+            raise ValueError(
+                "Both client_certificate and client_key must be provided for mTLS connection"
+            )
+        else:
+            ssl_creds = grpc.ssl_channel_credentials(root_certificates=ca_cert)
+        channel = grpc.secure_channel(experimental_host, ssl_creds)
+    else:
+        raise ValueError(
+            "TLS/mTLS connection requires ca_certificate to be set for experimental_host"
+        )
+    if interceptors is not None:
+        channel = grpc.intercept_channel(channel, *interceptors)
+    return transport_factory(channel=channel, credentials=AnonymousCredentials())

google/cloud/spanner_v1/client.py

@@ -48,7 +48,10 @@
 from google.cloud.spanner_v1 import __version__
 from google.cloud.spanner_v1 import ExecuteSqlRequest
 from google.cloud.spanner_v1 import DefaultTransactionOptions
-from google.cloud.spanner_v1._helpers import _merge_query_options
+from google.cloud.spanner_v1._helpers import (
+    _create_experimental_host_transport,
+    _merge_query_options,
+)
 from google.cloud.spanner_v1._helpers import _metadata_with_prefix
 from google.cloud.spanner_v1.instance import Instance
 from google.cloud.spanner_v1.metrics.constants import (
@@ -186,6 +189,30 @@ class Client(ClientWithProject):
 
     :raises: :class:`ValueError <exceptions.ValueError>` if both ``read_only``
              and ``admin`` are :data:`True`
+
+    :type use_plain_text: bool
+    :param use_plain_text: (Optional) Whether to use plain text for the connection.
+        This is intended only for experimental host spanner endpoints.
+        If set, this will override the `api_endpoint` in `client_options`.
+        If not set, the default behavior is to use TLS.
+
+    :type ca_certificate: str
+    :param ca_certificate: (Optional) The path to the CA certificate file used for TLS connection.
+        This is intended only for experimental host spanner endpoints.
+        If set, this will override the `api_endpoint` in `client_options`.
+        This is mandatory if the experimental_host requires a TLS connection.
+
+    :type client_certificate: str
+    :param client_certificate: (Optional) The path to the client certificate file used for mTLS connection.
+        This is intended only for experimental host spanner endpoints.
+        If set, this will override the `api_endpoint` in `client_options`.
+        This is mandatory if the experimental_host requires a mTLS connection.
+
+    :type client_key: str
+    :param client_key: (Optional) The path to the client key file used for mTLS connection.
+        This is intended only for experimental host spanner endpoints.
+        If set, this will override the `api_endpoint` in `client_options`.
+        This is mandatory if the experimental_host requires a mTLS connection.
     """
 
     _instance_admin_api = None
@@ -210,6 +237,10 @@ def __init__(
         default_transaction_options: Optional[DefaultTransactionOptions] = None,
         experimental_host=None,
         disable_builtin_metrics=False,
+        use_plain_text=False,
+        ca_certificate=None,
+        client_certificate=None,
+        client_key=None,
     ):
         self._emulator_host = _get_spanner_emulator_host()
         self._experimental_host = experimental_host
@@ -224,6 +255,12 @@ def __init__(
         if self._emulator_host:
             credentials = AnonymousCredentials()
         elif self._experimental_host:
+            # For all experimental host endpoints project is default
+            project = "default"
+            self._use_plain_text = use_plain_text
+            self._ca_certificate = ca_certificate
+            self._client_certificate = client_certificate
+            self._client_key = client_key
             credentials = AnonymousCredentials()
         elif isinstance(credentials, AnonymousCredentials):
             self._emulator_host = self._client_options.api_endpoint
@@ -259,7 +296,7 @@ def __init__(
         ):
             meter_provider = metrics.NoOpMeterProvider()
             try:
-                if not _get_spanner_emulator_host():
+                if not _get_spanner_emulator_host() and not self._experimental_host:
                     meter_provider = MeterProvider(
                         metric_readers=[
                             PeriodicExportingMetricReader(
@@ -339,8 +376,13 @@ def instance_admin_api(self):
                     transport=transport,
                 )
             elif self._experimental_host:
-                transport = InstanceAdminGrpcTransport(
-                    channel=grpc.insecure_channel(target=self._experimental_host)
+                transport = _create_experimental_host_transport(
+                    InstanceAdminGrpcTransport,
+                    self._experimental_host,
+                    self._use_plain_text,
+                    self._ca_certificate,
+                    self._client_certificate,
+                    self._client_key,
                 )
                 self._instance_admin_api = InstanceAdminClient(
                     client_info=self._client_info,
@@ -369,8 +411,13 @@ def database_admin_api(self):
                     transport=transport,
                 )
             elif self._experimental_host:
-                transport = DatabaseAdminGrpcTransport(
-                    channel=grpc.insecure_channel(target=self._experimental_host)
+                transport = _create_experimental_host_transport(
+                    DatabaseAdminGrpcTransport,
+                    self._experimental_host,
+                    self._use_plain_text,
+                    self._ca_certificate,
+                    self._client_certificate,
+                    self._client_key,
                 )
                 self._database_admin_api = DatabaseAdminClient(
                     client_info=self._client_info,
@@ -517,7 +564,6 @@ def instance(
             self._emulator_host,
             labels,
             processing_units,
-            self._experimental_host,
         )
 
     def list_instances(self, filter_="", page_size=None):

google/cloud/spanner_v1/database.py

@@ -55,6 +55,7 @@
     _metadata_with_prefix,
     _metadata_with_leader_aware_routing,
     _metadata_with_request_id,
+    _create_experimental_host_transport,
 )
 from google.cloud.spanner_v1.batch import Batch
 from google.cloud.spanner_v1.batch import MutationGroups
@@ -203,11 +204,9 @@ def __init__(
 
         self._pool = pool
         pool.bind(self)
-        is_experimental_host = self._instance.experimental_host is not None
+        self._experimental_host = self._instance._client._experimental_host
 
-        self._sessions_manager = DatabaseSessionsManager(
-            self, pool, is_experimental_host
-        )
+        self._sessions_manager = DatabaseSessionsManager(self, pool)
 
     @classmethod
     def from_pb(cls, database_pb, instance, pool=None):
@@ -452,9 +451,14 @@ def spanner_api(self):
                     client_info=client_info, transport=transport
                 )
                 return self._spanner_api
-            if self._instance.experimental_host is not None:
-                transport = SpannerGrpcTransport(
-                    channel=grpc.insecure_channel(self._instance.experimental_host)
+            if self._experimental_host is not None:
+                transport = _create_experimental_host_transport(
+                    SpannerGrpcTransport,
+                    self._experimental_host,
+                    self._instance._client._use_plain_text,
+                    self._instance._client._ca_certificate,
+                    self._instance._client._client_certificate,
+                    self._instance._client._client_key,
                 )
                 self._spanner_api = SpannerClient(
                     client_info=client_info,

google/cloud/spanner_v1/database_sessions_manager.py

@@ -62,10 +62,9 @@ class DatabaseSessionsManager(object):
     _MAINTENANCE_THREAD_POLLING_INTERVAL = timedelta(minutes=10)
     _MAINTENANCE_THREAD_REFRESH_INTERVAL = timedelta(days=7)
 
-    def __init__(self, database, pool, is_experimental_host: bool = False):
+    def __init__(self, database, pool):
         self._database = database
         self._pool = pool
-        self._is_experimental_host = is_experimental_host
 
         # Declare multiplexed session attributes. When a multiplexed session for the
         # database session manager is created, a maintenance thread is initialized to
@@ -89,7 +88,8 @@ def get_session(self, transaction_type: TransactionType) -> Session:
 
         session = (
             self._get_multiplexed_session()
-            if self._use_multiplexed(transaction_type) or self._is_experimental_host
+            if self._use_multiplexed(transaction_type)
+            or self._database._experimental_host is not None
             else self._pool.get()
         )
 

google/cloud/spanner_v1/instance.py

@@ -122,7 +122,6 @@ def __init__(
         emulator_host=None,
         labels=None,
         processing_units=None,
-        experimental_host=None,
     ):
         self.instance_id = instance_id
         self._client = client
@@ -143,7 +142,6 @@ def __init__(
             self._node_count = processing_units // PROCESSING_UNITS_PER_NODE
         self.display_name = display_name or instance_id
         self.emulator_host = emulator_host
-        self.experimental_host = experimental_host
         if labels is None:
             labels = {}
         self.labels = labels

google/cloud/spanner_v1/testing/database_test.py

@@ -17,6 +17,7 @@
 import google.auth.credentials
 from google.cloud.spanner_admin_database_v1 import DatabaseDialect
 from google.cloud.spanner_v1 import SpannerClient
+from google.cloud.spanner_v1._helpers import _create_experimental_host_transport
 from google.cloud.spanner_v1.database import Database, SPANNER_DATA_SCOPE
 from google.cloud.spanner_v1.services.spanner.transports import (
     SpannerGrpcTransport,
@@ -86,12 +87,18 @@ def spanner_api(self):
                     transport=transport,
                 )
                 return self._spanner_api
-            if self._instance.experimental_host is not None:
-                channel = grpc.insecure_channel(self._instance.experimental_host)
+            if self._experimental_host is not None:
                 self._x_goog_request_id_interceptor = XGoogRequestIDHeaderInterceptor()
                 self._interceptors.append(self._x_goog_request_id_interceptor)
-                channel = grpc.intercept_channel(channel, *self._interceptors)
-                transport = SpannerGrpcTransport(channel=channel)
+                transport = _create_experimental_host_transport(
+                    SpannerGrpcTransport,
+                    self._experimental_host,
+                    self._instance._client._use_plain_text,
+                    self._instance._client._ca_certificate,
+                    self._instance._client._client_certificate,
+                    self._instance._client._client_key,
+                    self._interceptors,
+                )
                 self._spanner_api = SpannerClient(
                     client_info=client_info,
                     transport=transport,

tests/system/_helpers.py

@@ -60,7 +60,14 @@
 EXPERIMENTAL_HOST = os.getenv(USE_EXPERIMENTAL_HOST_ENVVAR)
 USE_EXPERIMENTAL_HOST = EXPERIMENTAL_HOST is not None
 
-EXPERIMENTAL_HOST_PROJECT = "default"
+CA_CERTIFICATE_ENVVAR = "CA_CERTIFICATE"
+CA_CERTIFICATE = os.getenv(CA_CERTIFICATE_ENVVAR)
+CLIENT_CERTIFICATE_ENVVAR = "CLIENT_CERTIFICATE"
+CLIENT_CERTIFICATE = os.getenv(CLIENT_CERTIFICATE_ENVVAR)
+CLIENT_KEY_ENVVAR = "CLIENT_KEY"
+CLIENT_KEY = os.getenv(CLIENT_KEY_ENVVAR)
+USE_PLAIN_TEXT = CA_CERTIFICATE is None
+
 EXPERIMENTAL_HOST_INSTANCE = "default"
 
 DDL_STATEMENTS = (

tests/system/conftest.py

@@ -115,7 +115,10 @@ def spanner_client():
 
         credentials = AnonymousCredentials()
         return spanner_v1.Client(
-            project=_helpers.EXPERIMENTAL_HOST_PROJECT,
+            use_plain_text=_helpers.USE_PLAIN_TEXT,
+            ca_certificate=_helpers.CA_CERTIFICATE,
+            client_certificate=_helpers.CLIENT_CERTIFICATE,
+            client_key=_helpers.CLIENT_KEY,
             credentials=credentials,
             experimental_host=_helpers.EXPERIMENTAL_HOST,
         )

tests/system/test_dbapi.py

@@ -1442,6 +1442,10 @@ def test_user_agent(self, shared_instance, dbapi_database):
             experimental_host=_helpers.EXPERIMENTAL_HOST
             if _helpers.USE_EXPERIMENTAL_HOST
             else None,
+            use_plain_text=_helpers.USE_PLAIN_TEXT,
+            ca_certificate=_helpers.CA_CERTIFICATE,
+            client_certificate=_helpers.CLIENT_CERTIFICATE,
+            client_key=_helpers.CLIENT_KEY,
         )
         assert (
             conn.instance._client._client_info.user_agent