Istio integration (#421)

This the very first step for fission to integrate with Istio, which is an open platform to connect, manage, and secure microservices. With Istio, users are able to monitor functions usage and trace requests latency through dashboards. For more information, please visit http://fission.io/docs/

environments/fetcher/cmd/main.go

@@ -128,15 +128,6 @@ func specializePod(f *fetcher.Fetcher, fetchPayload *string, loadPayload *string
 		if err == nil && resp.StatusCode < 300 {
 			// Success
 			resp.Body.Close()
-			//On Success creates a file which is used as a readiness probe by Kubernetes for this container/pod
-			file, err := os.OpenFile("/tmp/ready", os.O_RDONLY|os.O_CREATE, 0666)
-			if err != nil {
-				log.Fatalf("Error creating readiness file: %v", err)
-			}
-			err = file.Close()
-			if err != nil {
-				log.Fatalf("Error closing readiness file: %v", err)
-			}
 			break
 		}