Pass api_path thru etcd3gw.client

Change-Id: I49c480f573a4ba8294627a3ce730b816ded10aed

etcd3gw/client.py

@@ -37,11 +37,13 @@ _EXCEPTIONS_BY_CODE = {
     requests.codes['precondition_failed']: exceptions.PreconditionFailedError,
 }
 
+DEFAULT_API_PATH = '/v3alpha/'
+
 
 class Etcd3Client(object):
     def __init__(self, host='localhost', port=2379, protocol="http",
                  ca_cert=None, cert_key=None, cert_cert=None, timeout=None,
-                 api_path='/v3alpha/'):
+                 api_path=DEFAULT_API_PATH):
         """Construct an client to talk to etcd3's grpc-gateway's /v3 HTTP API
 
         :param host:
@@ -409,7 +411,7 @@ class Etcd3Client(object):
 
 def client(host='localhost', port=2379,
            ca_cert=None, cert_key=None, cert_cert=None,
-           timeout=None, protocol="http"):
+           timeout=None, protocol="http", api_path=DEFAULT_API_PATH):
     """Return an instance of an Etcd3Client."""
     return Etcd3Client(host=host,
                        port=port,
@@ -417,4 +419,5 @@ def client(host='localhost', port=2379,
                        cert_key=cert_key,
                        cert_cert=cert_cert,
                        timeout=timeout,
+                       api_path=api_path,
                        protocol=protocol)

etcd3gw/tests/test_client.py

@@ -74,3 +74,8 @@ class TestEtcd3Gateway(base.TestCase):
                 self.assertEqual(e.detail_text, '''{
 "error": "etcdserver: unable to reach quorum"
 }''')
+
+    def test_client_api_path(self):
+        client = Etcd3Client(host="127.0.0.1", api_path='/v3/')
+        self.assertEqual("http://127.0.0.1:2379/v3/lease/grant",
+                         client.get_url("/lease/grant"))

releasenotes/notes/configurable-api-path-7652e756b6837e0b.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    The client adds support for specifying the etcd grpc-gateway's API path.
+    For backward compatibility, the path defaults to '/v3alpha/', but may
+    be overriden (e.g. '/v3') for newer versions of etcd that no longer support
+    the v3alpha API.