🌱 enable errorlint and unused linters (#1890)

* use %w instead of %v for wrapping errors

* do not use == or != to compare errors

* remove unused code

* fix formatting

.golangci.yml

@@ -7,6 +7,7 @@ linters:
   - depguard
   - dogsled
   - errcheck
+  - errorlint
   - exportloopref
   - goconst
   - gocritic
@@ -34,6 +35,7 @@ linters:
   - typecheck
   - unconvert
   - unparam
+  - unused
   - varcheck
   - whitespace
 

pkg/cache/multi_namespace_cache.go

@@ -55,7 +55,7 @@ func MultiNamespacedCacheBuilder(namespaces []string) NewCacheFunc {
 		// create a cache for cluster scoped resources
 		gCache, err := New(config, opts)
 		if err != nil {
-			return nil, fmt.Errorf("error creating global cache %v", err)
+			return nil, fmt.Errorf("error creating global cache: %w", err)
 		}
 
 		for _, ns := range namespaces {

pkg/client/config/config.go

@@ -123,7 +123,7 @@ func loadConfig(context string) (*rest.Config, error) {
 	if _, ok := os.LookupEnv("HOME"); !ok {
 		u, err := user.Current()
 		if err != nil {
-			return nil, fmt.Errorf("could not get current user: %v", err)
+			return nil, fmt.Errorf("could not get current user: %w", err)
 		}
 		loadingRules.Precedence = append(loadingRules.Precedence, filepath.Join(u.HomeDir, clientcmd.RecommendedHomeDir, clientcmd.RecommendedFileName))
 	}

pkg/client/fake/client.go

@@ -215,7 +215,7 @@ func (t versionedTracker) Add(obj runtime.Object) error {
 func (t versionedTracker) Create(gvr schema.GroupVersionResource, obj runtime.Object, ns string) error {
 	accessor, err := meta.Accessor(obj)
 	if err != nil {
-		return fmt.Errorf("failed to get accessor for object: %v", err)
+		return fmt.Errorf("failed to get accessor for object: %w", err)
 	}
 	if accessor.GetName() == "" {
 		return apierrors.NewInvalid(
@@ -269,7 +269,7 @@ func convertFromUnstructuredIfNecessary(s *runtime.Scheme, o runtime.Object) (ru
 func (t versionedTracker) Update(gvr schema.GroupVersionResource, obj runtime.Object, ns string) error {
 	accessor, err := meta.Accessor(obj)
 	if err != nil {
-		return fmt.Errorf("failed to get accessor for object: %v", err)
+		return fmt.Errorf("failed to get accessor for object: %w", err)
 	}
 
 	if accessor.GetName() == "" {
@@ -315,7 +315,7 @@ func (t versionedTracker) Update(gvr schema.GroupVersionResource, obj runtime.Ob
 	}
 	intResourceVersion, err := strconv.ParseUint(oldAccessor.GetResourceVersion(), 10, 64)
 	if err != nil {
-		return fmt.Errorf("can not convert resourceVersion %q to int: %v", oldAccessor.GetResourceVersion(), err)
+		return fmt.Errorf("can not convert resourceVersion %q to int: %w", oldAccessor.GetResourceVersion(), err)
 	}
 	intResourceVersion++
 	accessor.SetResourceVersion(strconv.FormatUint(intResourceVersion, 10))

pkg/client/namespaced_client.go

@@ -56,7 +56,7 @@ func (n *namespacedClient) RESTMapper() meta.RESTMapper {
 func (n *namespacedClient) Create(ctx context.Context, obj Object, opts ...CreateOption) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()
@@ -74,7 +74,7 @@ func (n *namespacedClient) Create(ctx context.Context, obj Object, opts ...Creat
 func (n *namespacedClient) Update(ctx context.Context, obj Object, opts ...UpdateOption) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()
@@ -92,7 +92,7 @@ func (n *namespacedClient) Update(ctx context.Context, obj Object, opts ...Updat
 func (n *namespacedClient) Delete(ctx context.Context, obj Object, opts ...DeleteOption) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()
@@ -110,7 +110,7 @@ func (n *namespacedClient) Delete(ctx context.Context, obj Object, opts ...Delet
 func (n *namespacedClient) DeleteAllOf(ctx context.Context, obj Object, opts ...DeleteAllOfOption) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	if isNamespaceScoped {
@@ -123,7 +123,7 @@ func (n *namespacedClient) DeleteAllOf(ctx context.Context, obj Object, opts ...
 func (n *namespacedClient) Patch(ctx context.Context, obj Object, patch Patch, opts ...PatchOption) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()
@@ -141,7 +141,7 @@ func (n *namespacedClient) Patch(ctx context.Context, obj Object, patch Patch, o
 func (n *namespacedClient) Get(ctx context.Context, key ObjectKey, obj Object) error {
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, n.Scheme(), n.RESTMapper())
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 	if isNamespaceScoped {
 		if key.Namespace != "" && key.Namespace != n.namespace {
@@ -179,7 +179,7 @@ func (nsw *namespacedClientStatusWriter) Update(ctx context.Context, obj Object,
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, nsw.namespacedclient.Scheme(), nsw.namespacedclient.RESTMapper())
 
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()
@@ -198,7 +198,7 @@ func (nsw *namespacedClientStatusWriter) Patch(ctx context.Context, obj Object,
 	isNamespaceScoped, err := objectutil.IsAPINamespaced(obj, nsw.namespacedclient.Scheme(), nsw.namespacedclient.RESTMapper())
 
 	if err != nil {
-		return fmt.Errorf("error finding the scope of the object: %v", err)
+		return fmt.Errorf("error finding the scope of the object: %w", err)
 	}
 
 	objectNamespace := obj.GetNamespace()

pkg/envtest/crd.go

@@ -20,6 +20,7 @@ import (
 	"bufio"
 	"bytes"
 	"context"
+	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
@@ -437,7 +438,7 @@ func readDocuments(fp string) ([][]byte, error) {
 		// Read document
 		doc, err := reader.Read()
 		if err != nil {
-			if err == io.EOF {
+			if errors.Is(err, io.EOF) {
 				break
 			}
 

pkg/envtest/webhook.go

@@ -117,7 +117,7 @@ func (o *WebhookInstallOptions) generateHostPort() (string, error) {
 	if o.LocalServingPort == 0 {
 		port, host, err := addr.Suggest(o.LocalServingHost)
 		if err != nil {
-			return "", fmt.Errorf("unable to grab random port for serving webhooks on: %v", err)
+			return "", fmt.Errorf("unable to grab random port for serving webhooks on: %w", err)
 		}
 		o.LocalServingPort = port
 		o.LocalServingHost = host
@@ -180,7 +180,7 @@ func WaitForWebhooks(config *rest.Config,
 		h := hook
 		gvk, err := apiutil.GVKForObject(h, scheme.Scheme)
 		if err != nil {
-			return fmt.Errorf("unable to get gvk for MutatingWebhookConfiguration %s: %v", hook.GetName(), err)
+			return fmt.Errorf("unable to get gvk for MutatingWebhookConfiguration %s: %w", hook.GetName(), err)
 		}
 
 		if _, ok := waitingFor[gvk]; !ok {
@@ -193,7 +193,7 @@ func WaitForWebhooks(config *rest.Config,
 		h := hook
 		gvk, err := apiutil.GVKForObject(h, scheme.Scheme)
 		if err != nil {
-			return fmt.Errorf("unable to get gvk for ValidatingWebhookConfiguration %s: %v", hook.GetName(), err)
+			return fmt.Errorf("unable to get gvk for ValidatingWebhookConfiguration %s: %w", hook.GetName(), err)
 		}
 
 		if _, ok := waitingFor[gvk]; !ok {
@@ -257,31 +257,31 @@ func (p *webhookPoller) poll() (done bool, err error) {
 func (o *WebhookInstallOptions) setupCA() error {
 	hookCA, err := certs.NewTinyCA()
 	if err != nil {
-		return fmt.Errorf("unable to set up webhook CA: %v", err)
+		return fmt.Errorf("unable to set up webhook CA: %w", err)
 	}
 
 	names := []string{"localhost", o.LocalServingHost, o.LocalServingHostExternalName}
 	hookCert, err := hookCA.NewServingCert(names...)
 	if err != nil {
-		return fmt.Errorf("unable to set up webhook serving certs: %v", err)
+		return fmt.Errorf("unable to set up webhook serving certs: %w", err)
 	}
 
 	localServingCertsDir, err := ioutil.TempDir("", "envtest-serving-certs-")
 	o.LocalServingCertDir = localServingCertsDir
 	if err != nil {
-		return fmt.Errorf("unable to create directory for webhook serving certs: %v", err)
+		return fmt.Errorf("unable to create directory for webhook serving certs: %w", err)
 	}
 
 	certData, keyData, err := hookCert.AsBytes()
 	if err != nil {
-		return fmt.Errorf("unable to marshal webhook serving certs: %v", err)
+		return fmt.Errorf("unable to marshal webhook serving certs: %w", err)
 	}
 
 	if err := ioutil.WriteFile(filepath.Join(localServingCertsDir, "tls.crt"), certData, 0640); err != nil { //nolint:gosec
-		return fmt.Errorf("unable to write webhook serving cert to disk: %v", err)
+		return fmt.Errorf("unable to write webhook serving cert to disk: %w", err)
 	}
 	if err := ioutil.WriteFile(filepath.Join(localServingCertsDir, "tls.key"), keyData, 0640); err != nil { //nolint:gosec
-		return fmt.Errorf("unable to write webhook serving key to disk: %v", err)
+		return fmt.Errorf("unable to write webhook serving key to disk: %w", err)
 	}
 
 	o.LocalServingCAData = certData

pkg/finalizer/finalizer.go

@@ -64,7 +64,7 @@ func (f finalizers) Finalize(ctx context.Context, obj client.Object) (Result, er
 				// object (e.g. it may set a condition and need a status update).
 				res.Updated = res.Updated || finalizerRes.Updated
 				res.StatusUpdated = res.StatusUpdated || finalizerRes.StatusUpdated
-				errList = append(errList, fmt.Errorf("finalizer %q failed: %v", key, err))
+				errList = append(errList, fmt.Errorf("finalizer %q failed: %w", key, err))
 			} else {
 				// If the finalizer succeeds, we remove the finalizer from the primary
 				// object's metadata, so we know it will need an update.

pkg/internal/testing/certs/tinyca.go

@@ -64,7 +64,7 @@ func (k CertPair) AsBytes() (cert []byte, key []byte, err error) {
 
 	rawKeyData, err := x509.MarshalPKCS8PrivateKey(k.Key)
 	if err != nil {
-		return nil, nil, fmt.Errorf("unable to encode private key: %v", err)
+		return nil, nil, fmt.Errorf("unable to encode private key: %w", err)
 	}
 
 	key = pem.EncodeToMemory(&pem.Block{
@@ -95,12 +95,12 @@ func newPrivateKey() (crypto.Signer, error) {
 func NewTinyCA() (*TinyCA, error) {
 	caPrivateKey, err := newPrivateKey()
 	if err != nil {
-		return nil, fmt.Errorf("unable to generate private key for CA: %v", err)
+		return nil, fmt.Errorf("unable to generate private key for CA: %w", err)
 	}
 	caCfg := certutil.Config{CommonName: "envtest-environment", Organization: []string{"envtest"}}
 	caCert, err := certutil.NewSelfSignedCACert(caCfg, caPrivateKey)
 	if err != nil {
-		return nil, fmt.Errorf("unable to generate certificate for CA: %v", err)
+		return nil, fmt.Errorf("unable to generate certificate for CA: %w", err)
 	}
 
 	return &TinyCA{
@@ -115,7 +115,7 @@ func (c *TinyCA) makeCert(cfg certutil.Config) (CertPair, error) {
 
 	key, err := newPrivateKey()
 	if err != nil {
-		return CertPair{}, fmt.Errorf("unable to create private key: %v", err)
+		return CertPair{}, fmt.Errorf("unable to create private key: %w", err)
 	}
 
 	serial := new(big.Int).Set(c.nextSerial)
@@ -140,12 +140,12 @@ func (c *TinyCA) makeCert(cfg certutil.Config) (CertPair, error) {
 
 	certRaw, err := x509.CreateCertificate(crand.Reader, &template, c.CA.Cert, key.Public(), c.CA.Key)
 	if err != nil {
-		return CertPair{}, fmt.Errorf("unable to create certificate: %v", err)
+		return CertPair{}, fmt.Errorf("unable to create certificate: %w", err)
 	}
 
 	cert, err := x509.ParseCertificate(certRaw)
 	if err != nil {
-		return CertPair{}, fmt.Errorf("generated invalid certificate, could not parse: %v", err)
+		return CertPair{}, fmt.Errorf("generated invalid certificate, could not parse: %w", err)
 	}
 
 	return CertPair{

pkg/internal/testing/process/arguments_test.go

@@ -225,12 +225,6 @@ var _ = Describe("Arguments Templates", func() {
 	})
 })
 
-type plainDefaults map[string][]string
-
-func (d plainDefaults) DefaultArgs() map[string][]string {
-	return d
-}
-
 var _ = Describe("Arguments", func() {
 	Context("when appending", func() {
 		It("should copy from defaults when appending for the first time", func() {

pkg/manager/internal.go

@@ -457,21 +457,21 @@ func (cm *controllerManager) Start(ctx context.Context) (err error) {
 	// between conversion webhooks and the cache sync (usually initial list) which causes the webhooks
 	// to never start because no cache can be populated.
 	if err := cm.runnables.Webhooks.Start(cm.internalCtx); err != nil {
-		if err != wait.ErrWaitTimeout {
+		if !errors.Is(err, wait.ErrWaitTimeout) {
 			return err
 		}
 	}
 
 	// Start and wait for caches.
 	if err := cm.runnables.Caches.Start(cm.internalCtx); err != nil {
-		if err != wait.ErrWaitTimeout {
+		if !errors.Is(err, wait.ErrWaitTimeout) {
 			return err
 		}
 	}
 
 	// Start the non-leaderelection Runnables after the cache has synced.
 	if err := cm.runnables.Others.Start(cm.internalCtx); err != nil {
-		if err != wait.ErrWaitTimeout {
+		if !errors.Is(err, wait.ErrWaitTimeout) {
 			return err
 		}
 	}
@@ -587,7 +587,7 @@ func (cm *controllerManager) engageStopProcedure(stopComplete <-chan struct{}) e
 	}()
 
 	<-cm.shutdownCtx.Done()
-	if err := cm.shutdownCtx.Err(); err != nil && err != context.Canceled {
+	if err := cm.shutdownCtx.Err(); err != nil && !errors.Is(err, context.Canceled) {
 		if errors.Is(err, context.DeadlineExceeded) {
 			if cm.gracefulShutdownTimeout > 0 {
 				return fmt.Errorf("failed waiting for all runnables to end within grace period of %s: %w", cm.gracefulShutdownTimeout, err)
@@ -597,6 +597,7 @@ func (cm *controllerManager) engageStopProcedure(stopComplete <-chan struct{}) e
 		// For any other error, return the error.
 		return err
 	}
+
 	return nil
 }
 

pkg/manager/manager.go

@@ -533,7 +533,7 @@ func defaultHealthProbeListener(addr string) (net.Listener, error) {
 
 	ln, err := net.Listen("tcp", addr)
 	if err != nil {
-		return nil, fmt.Errorf("error listening on %s: %v", addr, err)
+		return nil, fmt.Errorf("error listening on %s: %w", addr, err)
 	}
 	return ln, nil
 }

pkg/manager/manager_test.go

@@ -1806,12 +1806,6 @@ type startSignalingInformer struct {
 	cache.Cache
 }
 
-func (c *startSignalingInformer) started() bool {
-	c.mu.Lock()
-	defer c.mu.Unlock()
-	return c.wasStarted
-}
-
 func (c *startSignalingInformer) Start(ctx context.Context) error {
 	c.mu.Lock()
 	c.wasStarted = true

pkg/source/source.go

@@ -181,7 +181,7 @@ func (ks *Kind) WaitForSync(ctx context.Context) error {
 		return err
 	case <-ctx.Done():
 		ks.startCancel()
-		if ctx.Err() == context.Canceled {
+		if errors.Is(ctx.Err(), context.Canceled) {
 			return nil
 		}
 		return errors.New("timed out waiting for cache to be synced")

pkg/webhook/server.go

@@ -243,7 +243,7 @@ func (s *Server) Start(ctx context.Context) error {
 		certPool := x509.NewCertPool()
 		clientCABytes, err := ioutil.ReadFile(filepath.Join(s.CertDir, s.ClientCAName))
 		if err != nil {
-			return fmt.Errorf("failed to read client CA cert: %v", err)
+			return fmt.Errorf("failed to read client CA cert: %w", err)
 		}
 
 		ok := certPool.AppendCertsFromPEM(clientCABytes)
@@ -305,11 +305,11 @@ func (s *Server) StartedChecker() healthz.Checker {
 		d := &net.Dialer{Timeout: 10 * time.Second}
 		conn, err := tls.DialWithDialer(d, "tcp", net.JoinHostPort(s.Host, strconv.Itoa(s.Port)), config)
 		if err != nil {
-			return fmt.Errorf("webhook server is not reachable: %v", err)
+			return fmt.Errorf("webhook server is not reachable: %w", err)
 		}
 
 		if err := conn.Close(); err != nil {
-			return fmt.Errorf("webhook server is not reachable: closing connection: %v", err)
+			return fmt.Errorf("webhook server is not reachable: closing connection: %w", err)
 		}
 
 		return nil