Add support to reload environment variables (#20)

Author: pragnagopa

src/proto/FunctionRpc.proto

@@ -65,6 +65,10 @@ message StreamingMessage {
 
     // Worker logs a message back to the host
     RpcLog rpc_log = 2;
+
+    FunctionEnvironmentReLoadRequest function_environment_reload_request = 25;
+
+    FunctionEnvironmentReLoadResponse function_environment_reload_response = 26;
   }
 }
 
@@ -180,6 +184,16 @@ message WorkerStatusRequest{
 message WorkerStatusResponse {
 }
 
+message FunctionEnvironmentReLoadRequest {
+  // Environment variables from the current process
+  map<string, string> environment_variables = 1;
+}
+
+message FunctionEnvironmentReLoadResponse {
+  // Status of the response
+  StatusResult result = 3;
+}
+
 // Host tells the worker to load a Function
 message FunctionLoadRequest {
   // unique function identifier (avoid name collisions, facilitate reload case)