nope. no polymorphism in golang

cmd/gkeclient.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"fmt"
 	"log"
 
 	"github.com/binxio/simple-iap-proxy/flags"
@@ -17,7 +16,6 @@ func newGKEClientCmd() *cobra.Command {
 				Short: "starts a client side proxy, forwarding requests to the GKE cluster via the IAP",
 				Long: `The client will start a real HTTP/S proxy and forward any requests for,
 ip address of GKE cluster master endpoints, to the IAP proxy.`,
-				RunE: runProxy,
 			},
 		},
 	}
@@ -33,13 +31,10 @@ ip address of GKE cluster master endpoints, to the IAP proxy.`,
 	c.MarkFlagRequired("service-account")
 	c.MarkFlagRequired("target-url")
 	c.Flags().SortFlags = false
-	return &c.Command
-}
 
-func runProxy(c *cobra.Command, _ []string) error {
-	p, ok := interface{}(c).(gkeclient.Proxy)
-	if !ok {
-		return fmt.Errorf("command is not a proxy command")
+	c.RunE = func(cmd *cobra.Command, args []string) error {
+		return c.Run()
 	}
-	return p.Run()
+
+	return &c.Command
 }

cmd/gkeserver.go

@@ -1,15 +1,13 @@
 package cmd
 
 import (
-	"fmt"
-
 	"github.com/binxio/simple-iap-proxy/flags"
 	"github.com/binxio/simple-iap-proxy/gkeserver"
 	"github.com/spf13/cobra"
 )
 
 func newGKEServerCmd() *cobra.Command {
-	gkeServerCmd := gkeserver.ReverseProxy{
+	c := gkeserver.ReverseProxy{
 		RootCommand: flags.RootCommand{
 			Command: cobra.Command{
 				Use:   "gke-server",
@@ -19,18 +17,13 @@ reads the Host header of the http requests and if
 it matches the ip address of GKE cluster master endpoint, 
 forwards the request to it.
 `,
-				RunE: runReverseProxy,
 			},
 		},
 	}
-
-	return &gkeServerCmd.Command
-}
-
-func runReverseProxy(c *cobra.Command, _ []string) error {
-	s, ok := interface{}(c).(gkeserver.ReverseProxy)
-	if !ok {
-		return fmt.Errorf("command is not a reverse proxy command")
+	c.AddPersistentFlags()
+	c.RunE = func(cmd *cobra.Command, args []string) error {
+		return c.Run()
 	}
-	return s.Run()
+
+	return &c.Command
 }