kube-proxy: fix error wrapping, error handling and deprecated methods

Signed-off-by: Daman Arora <aroradaman@gmail.com>

cmd/kube-proxy/app/server.go

@@ -270,7 +270,7 @@ func (o *Options) Complete(fs *pflag.FlagSet) error {
 		// command line flags have priority). Otherwise `--config
 		// ... -v=5` doesn't work (config resets verbosity even
 		// when it contains no logging settings).
-		copyLogsFromFlags(fs, &c.Logging)
+		_ = copyLogsFromFlags(fs, &c.Logging)
 		o.config = c
 
 		if err := o.initWatcher(); err != nil {
@@ -312,7 +312,7 @@ func copyLogsFromFlags(from *pflag.FlagSet, to *logsapi.LoggingConfiguration) er
 			return
 		}
 		if setErr := f.Value.Set(fsFlag.Value.String()); setErr != nil {
-			err = fmt.Errorf("copying flag %s value: %v", f.Name, setErr)
+			err = fmt.Errorf("copying flag %s value: %w", f.Name, setErr)
 			return
 		}
 	})
@@ -464,10 +464,10 @@ func addressFromDeprecatedFlags(addr string, port int32) string {
 func newLenientSchemeAndCodecs() (*runtime.Scheme, *serializer.CodecFactory, error) {
 	lenientScheme := runtime.NewScheme()
 	if err := kubeproxyconfig.AddToScheme(lenientScheme); err != nil {
-		return nil, nil, fmt.Errorf("failed to add kube-proxy config API to lenient scheme: %v", err)
+		return nil, nil, fmt.Errorf("failed to add kube-proxy config API to lenient scheme: %w", err)
 	}
 	if err := kubeproxyconfigv1alpha1.AddToScheme(lenientScheme); err != nil {
-		return nil, nil, fmt.Errorf("failed to add kube-proxy config v1alpha1 API to lenient scheme: %v", err)
+		return nil, nil, fmt.Errorf("failed to add kube-proxy config v1alpha1 API to lenient scheme: %w", err)
 	}
 	lenientCodecs := serializer.NewCodecFactory(lenientScheme, serializer.DisableStrict)
 	return lenientScheme, &lenientCodecs, nil
@@ -505,7 +505,7 @@ func (o *Options) loadConfig(data []byte) (*kubeproxyconfig.KubeProxyConfigurati
 		if lenientErr != nil {
 			// Lenient decoding failed with the current version, return the
 			// original strict error.
-			return nil, fmt.Errorf("failed lenient decoding: %v", err)
+			return nil, fmt.Errorf("failed lenient decoding: %w", err)
 		}
 
 		// Continue with the v1alpha1 object that was decoded leniently, but emit a warning.
@@ -545,7 +545,7 @@ with the apiserver API to configure the proxy.`,
 
 			logs.InitLogs()
 			if err := logsapi.ValidateAndApplyAsField(&opts.config.Logging, utilfeature.DefaultFeatureGate, field.NewPath("logging")); err != nil {
-				return fmt.Errorf("initialize logging: %v", err)
+				return fmt.Errorf("initialize logging: %w", err)
 			}
 
 			cliflag.PrintFlags(cmd.Flags())
@@ -680,7 +680,7 @@ func newProxyServer(ctx context.Context, config *kubeproxyconfig.KubeProxyConfig
 	err, fatal := checkBadIPConfig(s, dualStackSupported)
 	if err != nil {
 		if fatal {
-			return nil, fmt.Errorf("kube-proxy configuration is incorrect: %v", err)
+			return nil, fmt.Errorf("kube-proxy configuration is incorrect: %w", err)
 		}
 		logger.Error(err, "Kube-proxy configuration may be incomplete or incorrect")
 	}
@@ -859,7 +859,7 @@ func serveHealthz(ctx context.Context, hz *healthcheck.ProxierHealthServer, errC
 		if err != nil {
 			logger.Error(err, "Healthz server failed")
 			if errCh != nil {
-				errCh <- fmt.Errorf("healthz server failed: %v", err)
+				errCh <- fmt.Errorf("healthz server failed: %w", err)
 				// if in hardfail mode, never retry again
 				blockCh := make(chan error)
 				<-blockCh
@@ -898,7 +898,7 @@ func serveMetrics(bindAddress string, proxyMode kubeproxyconfig.ProxyMode, enabl
 	fn := func() {
 		err := http.ListenAndServe(bindAddress, proxyMux)
 		if err != nil {
-			err = fmt.Errorf("starting metrics server failed: %v", err)
+			err = fmt.Errorf("starting metrics server failed: %w", err)
 			utilruntime.HandleError(err)
 			if errCh != nil {
 				errCh <- err

cmd/kube-proxy/app/server_test.go

@@ -20,15 +20,14 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"net"
+	"os"
 	"path"
 	"testing"
 	"time"
 
 	"github.com/google/go-cmp/cmp"
 	"github.com/spf13/pflag"
-	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
 	v1 "k8s.io/api/core/v1"
@@ -257,7 +256,7 @@ nodePortAddresses:
 
 		config, err := options.loadConfig([]byte(yaml))
 
-		assert.NoError(t, err, "unexpected error for %s: %v", tc.name, err)
+		require.NoError(t, err, "unexpected error for %s: %v", tc.name, err)
 
 		if diff := cmp.Diff(config, expected); diff != "" {
 			t.Fatalf("unexpected config for %s, diff = %s", tc.name, diff)
@@ -322,13 +321,11 @@ func TestLoadConfigFailures(t *testing.T) {
 			config := fmt.Sprintf("%s\n%s", version, tc.config)
 			_, err := options.loadConfig([]byte(config))
 
-			if assert.Error(t, err, tc.name) {
+			require.Error(t, err, tc.name)
-				if tc.expErr != "" {
+			require.Contains(t, err.Error(), tc.expErr)
-					assert.Contains(t, err.Error(), tc.expErr)
+
-				}
+			if tc.checkFn != nil {
-				if tc.checkFn != nil {
+				require.True(t, tc.checkFn(err), tc.name)
-					assert.True(t, tc.checkFn(err), tc.name)
-				}
 			}
 		})
 	}
@@ -375,7 +372,7 @@ func TestProcessHostnameOverrideFlag(t *testing.T) {
 					t.Fatalf("should error for this case %s", tc.name)
 				}
 			} else {
-				assert.NoError(t, err, "unexpected error %v", err)
+				require.NoError(t, err, "unexpected error %v", err)
 				if tc.expectedHostname != options.config.HostnameOverride {
 					t.Fatalf("expected hostname: %s, but got: %s", tc.expectedHostname, options.config.HostnameOverride)
 				}
@@ -500,12 +497,12 @@ kind: KubeProxyConfiguration
 			if len(tc.config) > 0 {
 				tmp := t.TempDir()
 				configFile := path.Join(tmp, "kube-proxy.conf")
-				require.NoError(t, ioutil.WriteFile(configFile, []byte(tc.config), 0666))
+				require.NoError(t, os.WriteFile(configFile, []byte(tc.config), 0666))
 				flags = append(flags, "--config", configFile)
 			}
 			require.NoError(t, fs.Parse(flags))
 			require.NoError(t, options.Complete(fs))
-			assert.Equal(t, tc.expected, options.config)
+			require.Equal(t, tc.expected, options.config)
 		})
 	}
 }