go-vet: Fix the Go vet findings (#1517)

Signed-off-by: Marco Franssen <marco.franssen@gmail.com>

Author: marcofranssen

controllers/fluentbitconfig_controller.go

@@ -157,7 +157,7 @@ func (r *FluentBitConfigReconciler) Reconcile(ctx context.Context, req ctrl.Requ
 
 			var ns string
 			if cfg.Spec.Namespace != nil {
-				ns = fmt.Sprintf(*cfg.Spec.Namespace)
+				ns = fmt.Sprint(*cfg.Spec.Namespace)
 			} else {
 				ns = os.Getenv("NAMESPACE")
 			}
@@ -402,8 +402,8 @@ func (r *FluentBitConfigReconciler) generateRewriteTagConfig(
 		return ""
 	}
 	var buf bytes.Buffer
-	buf.WriteString(fmt.Sprintf("[Filter]\n"))
-	buf.WriteString(fmt.Sprintf("    Name    rewrite_tag\n"))
+	buf.WriteString(fmt.Sprintln("[Filter]"))
+	buf.WriteString(fmt.Sprintln("    Name    rewrite_tag"))
 	buf.WriteString(fmt.Sprintf("    Match    %s\n", tag))
 	buf.WriteString(
 		fmt.Sprintf(

controllers/fluentdconfig_controller.go

@@ -18,13 +18,14 @@ package controllers
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"strings"
 	"time"
 
 	"github.com/go-logr/logr"
 	corev1 "k8s.io/api/core/v1"
-	"k8s.io/apimachinery/pkg/api/errors"
+	apierrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	ctrl "sigs.k8s.io/controller-runtime"
@@ -105,7 +106,7 @@ func (r *FluentdConfigReconciler) Reconcile(ctx context.Context, req ctrl.Reques
 	var fluentdList fluentdv1alpha1.FluentdList
 	// List all fluentd instances to bind the generated runtime configuration to each fluentd
 	if err := r.List(ctx, &fluentdList); err != nil {
-		if errors.IsNotFound(err) {
+		if apierrors.IsNotFound(err) {
 			r.Log.Info("can not find fluentd CR definition.")
 			return ctrl.Result{Requeue: true, RequeueAfter: time.Duration(1)}, nil
 		}
@@ -146,13 +147,13 @@ func (r *FluentdConfigReconciler) Reconcile(ctx context.Context, req ctrl.Reques
 			cfgResouces, errs := gpr.PatchAndFilterNamespacedLevelResources(sl, fmt.Sprintf("%s-%s-%s", fd.Kind, fd.Namespace, fd.Name), inputs, filters, outputs)
 			if len(errs) > 0 {
 				r.Log.Info("Patch and filter namespace level resources failed", "config", "default", "err", strings.Join(errs, ","))
-				return ctrl.Result{}, fmt.Errorf(strings.Join(errs, ","))
+				return ctrl.Result{}, errors.New(strings.Join(errs, ","))
 			}
 
 			err = gpr.IdentifyCopyAndPatchOutput(cfgResouces)
 			if err != nil {
 				r.Log.Info("IdentifyCopy and PatchOutput namespace level resources failed", "config", "default", "err", strings.Join(errs, ","))
-				return ctrl.Result{}, fmt.Errorf(strings.Join(errs, ","))
+				return ctrl.Result{}, errors.New(strings.Join(errs, ","))
 			}
 
 			// WithCfgResources will collect all plugins to generate main config
@@ -172,7 +173,7 @@ func (r *FluentdConfigReconciler) Reconcile(ctx context.Context, req ctrl.Reques
 		var clustercfgs fluentdv1alpha1.ClusterFluentdConfigList
 		// Use fluentd selector to match the cluster config.
 		if err := r.List(ctx, &clustercfgs, client.MatchingLabelsSelector{Selector: fdSelector}); err != nil {
-			if !errors.IsNotFound(err) {
+			if !apierrors.IsNotFound(err) {
 				return ctrl.Result{}, err
 			}
 		}
@@ -184,7 +185,7 @@ func (r *FluentdConfigReconciler) Reconcile(ctx context.Context, req ctrl.Reques
 		var cfgs fluentdv1alpha1.FluentdConfigList
 		// Use fluentd selector to match the cluster config
 		if err := r.List(ctx, &cfgs, client.MatchingLabelsSelector{Selector: fdSelector}); err != nil {
-			if !errors.IsNotFound(err) {
+			if !apierrors.IsNotFound(err) {
 				return ctrl.Result{}, err
 			}
 		}

docs/best-practice/forwarding-logs-via-http/main.go

@@ -2,7 +2,7 @@ package main
 
 import (
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 )
@@ -16,17 +16,17 @@ type Message struct {
 // Sample HTTP receiver for this demo
 func main() {
 	h := func(w http.ResponseWriter, req *http.Request) {
-		b, err := ioutil.ReadAll(req.Body)
+		b, err := io.ReadAll(req.Body)
 		defer req.Body.Close()
 		if err != nil {
-			log.Printf(err.Error())
+			log.Print(err.Error())
 			return
 		}
 
 		var msg []Message
 		err = json.Unmarshal(b, &msg)
 		if err != nil {
-			log.Printf(err.Error())
+			log.Print(err.Error())
 			return
 		}
 

tests/e2e/fluentd/cfgrender_suite_test.go

@@ -45,7 +45,7 @@ func TestCompareFluentdMainAppConfig(t *testing.T) {
 		k8sClient = kc
 		Expect(k8sClient).NotTo(BeNil())
 
-		fmt.Fprintf(GinkgoWriter, time.Now().Format(time.StampMilli)+": Info: Setup Suite Execution\n")
+		fmt.Fprintf(GinkgoWriter, "%s: Info: Setup Suite Execution\n", time.Now().Format(time.StampMilli))
 	}, 60)
 
 	AfterSuite(func() {