Upgrade the golangci-lint dependency.

* The older version of `golangci-lint` on version `v1.52.1` was
  consuming an inordinate amount of memory, and thus ended up getting
  killed by the OS mid run.
  See golangci/golangci-lint#3582.

* Upgrade to a newer version of `golangci-lint`, `v1.61.0`.

* Fix all lint errors reported with the newer version.

Author: renormalize

go.mod

@@ -1,6 +1,6 @@
 module github.com/gardener/etcd-wrapper
 
-go 1.23.1
+go 1.23
 
 // These are test-only dependencies
 require github.com/onsi/gomega v1.27.5

hack/tools.mk

@@ -8,14 +8,11 @@ GOLANGCI_LINT              := $(TOOLS_BIN_DIR)/golangci-lint
 GO_ADD_LICENSE             := $(TOOLS_BIN_DIR)/addlicense
 
 # default tool versions
-GOLANGCI_LINT_VERSION ?= v1.51.2
+GOLANGCI_LINT_VERSION ?= v1.61.0
 GO_ADD_LICENSE_VERSION ?= latest
 
 export TOOLS_BIN_DIR := $(TOOLS_BIN_DIR)
 export PATH := $(abspath $(TOOLS_BIN_DIR)):$(PATH)
-$(info "TOOLS_BIN_DIR from tools.mk", $(TOOLS_BIN_DIR))
-$(info "TOOLS_DIR from tools.mk", $(TOOLS_DIR))
-$(info "PATH from tools.mk", $(PATH))
 
 #########################################
 # Tools                                 #

internal/app/fakes.go

@@ -14,31 +14,31 @@ import (
 type EtcdFakeKV struct{}
 
 // Get gets a value for a given key.
-func (c *EtcdFakeKV) Get(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.GetResponse, error) {
+func (c *EtcdFakeKV) Get(_ context.Context, _ string, _ ...clientv3.OpOption) (*clientv3.GetResponse, error) {
 	return nil, nil
 }
 
 // Put puts a value for a given key.
-func (c *EtcdFakeKV) Put(ctx context.Context, key, val string, opts ...clientv3.OpOption) (*clientv3.PutResponse, error) {
+func (c *EtcdFakeKV) Put(_ context.Context, _, _ string, _ ...clientv3.OpOption) (*clientv3.PutResponse, error) {
 	return nil, nil
 }
 
 // Delete deletes an entry with a given key.
-func (c *EtcdFakeKV) Delete(ctx context.Context, key string, opts ...clientv3.OpOption) (*clientv3.DeleteResponse, error) {
+func (c *EtcdFakeKV) Delete(_ context.Context, _ string, _ ...clientv3.OpOption) (*clientv3.DeleteResponse, error) {
 	return nil, nil
 }
 
 // Compact compacts etcd KV history before the given rev.
-func (c *EtcdFakeKV) Compact(ctx context.Context, rev int64, opts ...clientv3.CompactOption) (*clientv3.CompactResponse, error) {
+func (c *EtcdFakeKV) Compact(_ context.Context, _ int64, _ ...clientv3.CompactOption) (*clientv3.CompactResponse, error) {
 	return nil, nil
 }
 
 // Txn creates a transaction.
-func (c *EtcdFakeKV) Txn(ctx context.Context) clientv3.Txn {
+func (c *EtcdFakeKV) Txn(_ context.Context) clientv3.Txn {
 	return nil
 }
 
 // Do applies a single Op on KV without a transaction.
-func (c *EtcdFakeKV) Do(ctx context.Context, op clientv3.Op) (clientv3.OpResponse, error) {
+func (c *EtcdFakeKV) Do(_ context.Context, _ clientv3.Op) (clientv3.OpResponse, error) {
 	return clientv3.OpResponse{}, nil
 }

internal/bootstrap/bootstrap_test.go

@@ -227,7 +227,7 @@ func deleteTestDir(t *testing.T, testDir string) {
 
 func getTestHttpClient(responseCode int, responseBody []byte) *http.Client {
 	return &http.Client{
-		Transport: TestRoundTripper(func(req *http.Request) *http.Response {
+		Transport: TestRoundTripper(func(_ *http.Request) *http.Response {
 			var contentLen int64
 			if responseBody != nil {
 				contentLen = int64(len(responseBody))

internal/brclient/brclient_test.go

@@ -204,7 +204,7 @@ func TestNewDefaultClient(t *testing.T) {
 
 func getTestHttpClient(responseCode int, responseBody []byte) *http.Client {
 	return &http.Client{
-		Transport: TestRoundTripper(func(req *http.Request) *http.Response {
+		Transport: TestRoundTripper(func(_ *http.Request) *http.Response {
 			var contentLen int64
 			if responseBody != nil {
 				contentLen = int64(len(responseBody))

internal/util/retry_test.go

@@ -44,7 +44,7 @@ func TestErrorIfExceedsAttempts(t *testing.T) {
 	for _, entry := range table {
 		g := NewWithT(t)
 		logger := zaptest.NewLogger(t)
-		t.Run(entry.description, func(t *testing.T) {
+		t.Run(entry.description, func(_ *testing.T) {
 			defer clearRetryResults()
 			result := Retry(context.Background(), logger, operation, neverSucceeds, numAttempts, backOff, entry.canRetryFn)
 			g.Expect(result.Value).To(Equal(attemptFailed))