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/

common.go

@@ -18,6 +18,7 @@ package fission
 
 import (
 	"fmt"
+	"net"
 	"os"
 	"os/signal"
 	"runtime/debug"
@@ -40,3 +41,14 @@ func SetupStackTraceHandler() {
 		os.Exit(1)
 	}()
 }
+
+// IsNetworkError returns true if an error is a network error, and false otherwise.
+func IsNetworkError(err error) bool {
+	_, ok := err.(net.Error)
+	return ok
+}
+
+// GetFunctionIstioServiceName return service name of function for istio feature
+func GetFunctionIstioServiceName(fnName, fnNamespace string) string {
+	return fmt.Sprintf("istio-%v-%v", fnName, fnNamespace)
+}