initial files to support grpc server/client

daemon/core/grpc/client.py

@@ -0,0 +1,38 @@
+from __future__ import print_function
+import logging
+from contextlib import contextmanager
+
+import grpc
+
+import core_pb2
+import core_pb2_grpc
+
+
+class CoreApiClient(object):
+    def __init__(self, address="localhost:50051"):
+        self.address = address
+        self.stub = None
+
+    def get_sessions(self):
+        return self.stub.GetSessions(core_pb2.SessionsRequest())
+
+    @contextmanager
+    def connect(self):
+        channel = grpc.insecure_channel(self.address)
+        try:
+            self.stub = core_pb2_grpc.CoreApiStub(channel)
+            yield channel
+        finally:
+            channel.close()
+
+
+def main():
+    client = CoreApiClient()
+    with client.connect():
+        response = client.get_sessions()
+        print("core client received: %s" % response)
+
+
+if __name__ == "__main__":
+    logging.basicConfig()
+    main()