feat: add mtls support (#7)

docs/conf.py

@@ -38,6 +38,7 @@
     "sphinx.ext.napoleon",
     "sphinx.ext.todo",
     "sphinx.ext.viewcode",
+    "recommonmark",
 ]
 
 # autodoc/autosummary flags
@@ -49,10 +50,6 @@
 # Add any paths that contain templates here, relative to this directory.
 templates_path = ["_templates"]
 
-# Allow markdown includes (so releases.md can include CHANGLEOG.md)
-# http://www.sphinx-doc.org/en/master/markdown.html
-source_parsers = {".md": "recommonmark.parser.CommonMarkParser"}
-
 # The suffix(es) of source filenames.
 # You can specify multiple suffix as a list of string:
 # source_suffix = ['.rst', '.md']

google/cloud/memcache_v1beta2/services/cloud_memcache/client.py

@@ -16,7 +16,8 @@
 #
 
 from collections import OrderedDict
-from typing import Dict, Sequence, Tuple, Type, Union
+import re
+from typing import Callable, Dict, Sequence, Tuple, Type, Union
 import pkg_resources
 
 import google.api_core.client_options as ClientOptions  # type: ignore
@@ -90,8 +91,38 @@ class CloudMemcacheClient(metaclass=CloudMemcacheClientMeta):
     -  ``projects/my-memcached-project/locations/us-central1/instances/my-memcached``
     """
 
-    DEFAULT_OPTIONS = ClientOptions.ClientOptions(
-        api_endpoint="memcache.googleapis.com"
+    @staticmethod
+    def _get_default_mtls_endpoint(api_endpoint):
+        """Convert api endpoint to mTLS endpoint.
+        Convert "*.sandbox.googleapis.com" and "*.googleapis.com" to
+        "*.mtls.sandbox.googleapis.com" and "*.mtls.googleapis.com" respectively.
+        Args:
+            api_endpoint (Optional[str]): the api endpoint to convert.
+        Returns:
+            str: converted mTLS api endpoint.
+        """
+        if not api_endpoint:
+            return api_endpoint
+
+        mtls_endpoint_re = re.compile(
+            r"(?P<name>[^.]+)(?P<mtls>\.mtls)?(?P<sandbox>\.sandbox)?(?P<googledomain>\.googleapis\.com)?"
+        )
+
+        m = mtls_endpoint_re.match(api_endpoint)
+        name, mtls, sandbox, googledomain = m.groups()
+        if mtls or not googledomain:
+            return api_endpoint
+
+        if sandbox:
+            return api_endpoint.replace(
+                "sandbox.googleapis.com", "mtls.sandbox.googleapis.com"
+            )
+
+        return api_endpoint.replace(".googleapis.com", ".mtls.googleapis.com")
+
+    DEFAULT_ENDPOINT = "memcache.googleapis.com"
+    DEFAULT_MTLS_ENDPOINT = _get_default_mtls_endpoint.__func__(  # type: ignore
+        DEFAULT_ENDPOINT
     )
 
     @classmethod
@@ -121,12 +152,21 @@ def instance_path(project: str, location: str, instance: str) -> str:
             project=project, location=location, instance=instance
         )
 
+    @staticmethod
+    def parse_instance_path(path: str) -> Dict[str, str]:
+        """Parse a instance path into its component segments."""
+        m = re.match(
+            r"^projects/(?P<project>.+?)/locations/(?P<location>.+?)/instances/(?P<instance>.+?)$",
+            path,
+        )
+        return m.groupdict() if m else {}
+
     def __init__(
         self,
         *,
         credentials: credentials.Credentials = None,
         transport: Union[str, CloudMemcacheTransport] = None,
-        client_options: ClientOptions = DEFAULT_OPTIONS,
+        client_options: ClientOptions = None,
     ) -> None:
         """Instantiate the cloud memcache client.
 
@@ -140,6 +180,17 @@ def __init__(
                 transport to use. If set to None, a transport is chosen
                 automatically.
             client_options (ClientOptions): Custom options for the client.
+                (1) The ``api_endpoint`` property can be used to override the
+                default endpoint provided by the client.
+                (2) If ``transport`` argument is None, ``client_options`` can be
+                used to create a mutual TLS transport. If ``client_cert_source``
+                is provided, mutual TLS transport will be created with the given
+                ``api_endpoint`` or the default mTLS endpoint, and the client
+                SSL credentials obtained from ``client_cert_source``.
+
+        Raises:
+            google.auth.exceptions.MutualTlsChannelError: If mutual TLS transport
+                creation failed for any reason.
         """
         if isinstance(client_options, dict):
             client_options = ClientOptions.from_dict(client_options)
@@ -148,17 +199,46 @@ def __init__(
         # Ordinarily, we provide the transport, but allowing a custom transport
         # instance provides an extensibility point for unusual situations.
         if isinstance(transport, CloudMemcacheTransport):
+            # transport is a CloudMemcacheTransport instance.
             if credentials:
                 raise ValueError(
                     "When providing a transport instance, "
                     "provide its credentials directly."
                 )
             self._transport = transport
-        else:
+        elif client_options is None or (
+            client_options.api_endpoint is None
+            and client_options.client_cert_source is None
+        ):
+            # Don't trigger mTLS if we get an empty ClientOptions.
             Transport = type(self).get_transport_class(transport)
             self._transport = Transport(
+                credentials=credentials, host=self.DEFAULT_ENDPOINT
+            )
+        else:
+            # We have a non-empty ClientOptions. If client_cert_source is
+            # provided, trigger mTLS with user provided endpoint or the default
+            # mTLS endpoint.
+            if client_options.client_cert_source:
+                api_mtls_endpoint = (
+                    client_options.api_endpoint
+                    if client_options.api_endpoint
+                    else self.DEFAULT_MTLS_ENDPOINT
+                )
+            else:
+                api_mtls_endpoint = None
+
+            api_endpoint = (
+                client_options.api_endpoint
+                if client_options.api_endpoint
+                else self.DEFAULT_ENDPOINT
+            )
+
+            self._transport = CloudMemcacheGrpcTransport(
                 credentials=credentials,
-                host=client_options.api_endpoint or "memcache.googleapis.com",
+                host=api_endpoint,
+                api_mtls_endpoint=api_mtls_endpoint,
+                client_cert_source=client_options.client_cert_source,
             )
 
     def list_instances(

google/cloud/memcache_v1beta2/services/cloud_memcache/transports/grpc.py

@@ -15,11 +15,13 @@
 # limitations under the License.
 #
 
-from typing import Callable, Dict
+from typing import Callable, Dict, Tuple
 
 from google.api_core import grpc_helpers  # type: ignore
 from google.api_core import operations_v1  # type: ignore
 from google.auth import credentials  # type: ignore
+from google.auth.transport.grpc import SslCredentials  # type: ignore
+
 
 import grpc  # type: ignore
 
@@ -66,7 +68,9 @@ def __init__(
         *,
         host: str = "memcache.googleapis.com",
         credentials: credentials.Credentials = None,
-        channel: grpc.Channel = None
+        channel: grpc.Channel = None,
+        api_mtls_endpoint: str = None,
+        client_cert_source: Callable[[], Tuple[bytes, bytes]] = None
     ) -> None:
         """Instantiate the transport.
 
@@ -80,20 +84,55 @@ def __init__(
                 This argument is ignored if ``channel`` is provided.
             channel (Optional[grpc.Channel]): A ``Channel`` instance through
                 which to make calls.
+            api_mtls_endpoint (Optional[str]): The mutual TLS endpoint. If
+                provided, it overrides the ``host`` argument and tries to create
+                a mutual TLS channel with client SSL credentials from
+                ``client_cert_source`` or applicatin default SSL credentials.
+            client_cert_source (Optional[Callable[[], Tuple[bytes, bytes]]]): A
+                callback to provide client SSL certificate bytes and private key
+                bytes, both in PEM format. It is ignored if ``api_mtls_endpoint``
+                is None.
+
+        Raises:
+          google.auth.exceptions.MutualTlsChannelError: If mutual TLS transport
+              creation failed for any reason.
         """
-        # Sanity check: Ensure that channel and credentials are not both
-        # provided.
         if channel:
+            # Sanity check: Ensure that channel and credentials are not both
+            # provided.
             credentials = False
 
+            # If a channel was explicitly provided, set it.
+            self._grpc_channel = channel
+        elif api_mtls_endpoint:
+            host = (
+                api_mtls_endpoint
+                if ":" in api_mtls_endpoint
+                else api_mtls_endpoint + ":443"
+            )
+
+            # Create SSL credentials with client_cert_source or application
+            # default SSL credentials.
+            if client_cert_source:
+                cert, key = client_cert_source()
+                ssl_credentials = grpc.ssl_channel_credentials(
+                    certificate_chain=cert, private_key=key
+                )
+            else:
+                ssl_credentials = SslCredentials().ssl_credentials
+
+            # create a new channel. The provided one is ignored.
+            self._grpc_channel = grpc_helpers.create_channel(
+                host,
+                credentials=credentials,
+                ssl_credentials=ssl_credentials,
+                scopes=self.AUTH_SCOPES,
+            )
+
         # Run the base constructor.
         super().__init__(host=host, credentials=credentials)
         self._stubs = {}  # type: Dict[str, Callable]
 
-        # If a channel was explicitly provided, set it.
-        if channel:
-            self._grpc_channel = channel
-
     @classmethod
     def create_channel(
         cls,

mypy.ini

@@ -1,3 +1,3 @@
 [mypy]
-python_version = 3.5
+python_version = 3.6
 namespace_packages = True

setup.py

@@ -40,9 +40,7 @@
     platforms="Posix; MacOS X; Windows",
     include_package_data=True,
     install_requires=(
-        "google-api-core >= 1.8.0, < 2.0.0dev",
-        "googleapis-common-protos >= 1.5.8",
-        "grpcio >= 1.10.0",
+        "google-api-core[grpc] >= 1.17.0, < 2.0.0dev",
         "proto-plus >= 0.4.0",
     ),
     python_requires=">=3.6",