From 7caf51daa4007bc2f8b9af95f918cf61989a997e Mon Sep 17 00:00:00 2001
From: Odin Ugedal <odin@ugedal.com>
Date: Thu, 27 Jun 2019 21:50:29 +0200
Subject: [PATCH] Remove duplicate error messages from cli commands

Since we never use the cobras "SilenceErrors" or "SilenceUsage",
a command executed with "cmd.Execute()" will never return an error
without printing it.

The current behavior results in all error messages being printed twice:

Example:

$ kubectl abc
Error: unknown command "abc" for "kubectl"
Run 'kubectl --help' for usage.
unknown command "abc" for "kubectl"

This applies to all cli commands using Cobra. To verify, follow the code
path of the Execute function:

https://github.com/spf13/cobra/blob/c439c4fa0937/command.go#L793
Signed-off-by: Odin Ugedal <odin@ugedal.com>
---
 cmd/cloud-controller-manager/controller-manager.go | 2 --
 cmd/hyperkube/main.go                              | 1 -
 cmd/kube-apiserver/apiserver.go                    | 2 --
 cmd/kube-controller-manager/controller-manager.go  | 2 --
 cmd/kube-proxy/proxy.go                            | 2 --
 cmd/kube-scheduler/scheduler.go                    | 2 --
 cmd/kubeadm/kubeadm.go                             | 3 ---
 cmd/kubectl/kubectl.go                             | 2 --
 cmd/kubelet/kubelet.go                             | 2 --
 cmd/kubemark/hollow-node.go                        | 1 -
 10 files changed, 19 deletions(-)

diff --git a/cmd/cloud-controller-manager/controller-manager.go b/cmd/cloud-controller-manager/controller-manager.go
index b00af712b7f..4857416db9e 100644
--- a/cmd/cloud-controller-manager/controller-manager.go
+++ b/cmd/cloud-controller-manager/controller-manager.go
@@ -20,7 +20,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -48,7 +47,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/hyperkube/main.go b/cmd/hyperkube/main.go
index 7f7034423a9..3340e68e62a 100644
--- a/cmd/hyperkube/main.go
+++ b/cmd/hyperkube/main.go
@@ -61,7 +61,6 @@ func main() {
 
 	basename := filepath.Base(os.Args[0])
 	if err := commandFor(basename, hyperkubeCommand, allCommandFns).Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kube-apiserver/apiserver.go b/cmd/kube-apiserver/apiserver.go
index 98002a16b0a..ca524ab62c4 100644
--- a/cmd/kube-apiserver/apiserver.go
+++ b/cmd/kube-apiserver/apiserver.go
@@ -19,7 +19,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -43,7 +42,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kube-controller-manager/controller-manager.go b/cmd/kube-controller-manager/controller-manager.go
index b5f94549b5a..4cfd37c8ed5 100644
--- a/cmd/kube-controller-manager/controller-manager.go
+++ b/cmd/kube-controller-manager/controller-manager.go
@@ -21,7 +21,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -45,7 +44,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kube-proxy/proxy.go b/cmd/kube-proxy/proxy.go
index 9b0e31d9ba7..b25dea06d27 100644
--- a/cmd/kube-proxy/proxy.go
+++ b/cmd/kube-proxy/proxy.go
@@ -18,7 +18,6 @@ package main
 
 import (
 	goflag "flag"
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -47,7 +46,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kube-scheduler/scheduler.go b/cmd/kube-scheduler/scheduler.go
index 5f4af458dc6..f2e4c1c4fcf 100644
--- a/cmd/kube-scheduler/scheduler.go
+++ b/cmd/kube-scheduler/scheduler.go
@@ -17,7 +17,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -45,7 +44,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kubeadm/kubeadm.go b/cmd/kubeadm/kubeadm.go
index 1b3d58fa171..ba4b34622ab 100644
--- a/cmd/kubeadm/kubeadm.go
+++ b/cmd/kubeadm/kubeadm.go
@@ -17,7 +17,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"os"
 
 	"k8s.io/klog"
@@ -27,8 +26,6 @@ import (
 func main() {
 	klog.InitFlags(nil)
 	if err := app.Run(); err != nil {
-		fmt.Fprintf(os.Stderr, "error: %v\n", err)
 		os.Exit(1)
 	}
-	os.Exit(0)
 }
diff --git a/cmd/kubectl/kubectl.go b/cmd/kubectl/kubectl.go
index dff1143b017..9ae468aedc1 100644
--- a/cmd/kubectl/kubectl.go
+++ b/cmd/kubectl/kubectl.go
@@ -18,7 +18,6 @@ package main
 
 import (
 	goflag "flag"
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -48,7 +47,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kubelet/kubelet.go b/cmd/kubelet/kubelet.go
index 2bd4d59d0b2..92b8ac76a0e 100644
--- a/cmd/kubelet/kubelet.go
+++ b/cmd/kubelet/kubelet.go
@@ -21,7 +21,6 @@ limitations under the License.
 package main
 
 import (
-	"fmt"
 	"math/rand"
 	"os"
 	"time"
@@ -40,7 +39,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }
diff --git a/cmd/kubemark/hollow-node.go b/cmd/kubemark/hollow-node.go
index 5ce7bb29fbb..79bec40d456 100644
--- a/cmd/kubemark/hollow-node.go
+++ b/cmd/kubemark/hollow-node.go
@@ -116,7 +116,6 @@ func main() {
 	defer logs.FlushLogs()
 
 	if err := command.Execute(); err != nil {
-		fmt.Fprintf(os.Stderr, "%v\n", err)
 		os.Exit(1)
 	}
 }