lazy aiohttp client creation (#115)

Author: Revolution1

etcd3/aio_client.py

@@ -16,7 +16,7 @@
 from .errors import Etcd3Exception
 from .errors import Etcd3StreamError
 from .errors import get_client_error
-from .utils import iter_json_string, Etcd3Warning
+from .utils import iter_json_string, Etcd3Warning, cached_property
 
 
 class ModelizedResponse(object):
@@ -174,8 +174,11 @@ def __init__(self, host='127.0.0.1', port=2379, protocol='http',
             ssl_context.verify_mode = cert_reqs
             ssl_context.load_verify_locations(cafile=cafile)
             ssl_context.load_cert_chain(*self.cert)
-        connector = aiohttp.TCPConnector(limit=pool_size, ssl=self.ssl_context)
-        self.session = aiohttp.ClientSession(connector=connector)
+
+    @cached_property
+    def session(self):
+        connector = aiohttp.TCPConnector(limit=self.pool_size, ssl=self.ssl_context)
+        return aiohttp.ClientSession(connector=connector)
 
     async def close(self):
         """

etcd3/baseclient.py

@@ -66,6 +66,7 @@ def __init__(self, host='127.0.0.1', port=2379, protocol='http',
         if not user_agent:
             self.user_agent = 'etcd3-py/' + __version__
         self.timeout = timeout
+        self.pool_size = pool_size
         self.headers = headers or {}
         self.username = username
         self.password = password

setup.cfg

@@ -22,4 +22,3 @@ test = pytest
 
 [metadata]
 license_file = LICENSE
-