Fix doing IAM requests on original endpoint

Author: MAnyKey

setup.py

@@ -4,7 +4,7 @@
     include=['yandexcloud*', 'yandex*'])
 
 setup(name='yandexcloud',
-    version='0.3',
+    version='0.4',
     description='The Yandex.Cloud official SDK',
     url='https://github.com/yandex-cloud/python-sdk',
     author='Yandex LLC',
@@ -13,6 +13,7 @@
     install_requires=[
         'grpcio',
         'googleapis-common-protos',
+        'six',
     ],
     packages=packages,
     zip_safe=False)

yandexcloud/_auth_plugin.py

@@ -4,6 +4,7 @@
 from datetime import datetime
 
 import grpc
+from six.moves.urllib.parse import urlparse
 
 from yandex.cloud.iam.v1.iam_token_service_pb2 import CreateIamTokenRequest
 from yandex.cloud.iam.v1.iam_token_service_pb2_grpc import IamTokenServiceStub
@@ -12,9 +13,10 @@
 
 
 class Credentials(grpc.AuthMetadataPlugin):
-    def __init__(self, oauth_token, channel):
+    def __init__(self, oauth_token, lazy_channel):
         self._oauth_token = oauth_token
-        self._client = IamTokenServiceStub(channel)
+        self._lazy_channel = lazy_channel
+        self._channel = None
         self._cached_iam_token = None
         self._iam_token_timestamp = None
 
@@ -25,13 +27,17 @@ def __call__(self, context, callback):
             callback(None, exception)
 
     def _call(self, context, callback):
-        if context.service_url == '/yandex.cloud.iam.v1.IamTokenService' or \
-            context.service_url == '/yandex.cloud.endpoint.ApiEndpointService':
+        u = urlparse(context.service_url)
+        if u.path == '/yandex.cloud.iam.v1.IamTokenService' or \
+            u.path == '/yandex.cloud.endpoint.ApiEndpointService':
             callback(None, None)
             return
 
+        if not self._channel:
+            self._channel = self._lazy_channel()
+
         if self._cached_iam_token is None or not self._fresh():
-            token_future = self._client.Create.future(CreateIamTokenRequest(
+            token_future = IamTokenServiceStub(self._channel).Create.future(CreateIamTokenRequest(
                 yandex_passport_oauth_token=self._oauth_token))
             token_future.add_done_callback(self.create_done_callback(callback))
             return

yandexcloud/_channels.py

@@ -40,7 +40,7 @@ def channel(self, endpoint):
             endpoints = resp.endpoints
 
             plugin = _auth_plugin.Credentials(
-                self._token, self._unauthenticated_channel)
+                self._token, lambda: self._channels["iam"])
             call_creds = grpc.metadata_call_credentials(plugin)
             creds = grpc.composite_channel_credentials(
                 self._channel_creds, call_creds)