chore: fix golangci-lint (#307)

.golangci.yaml

@@ -0,0 +1,15 @@
+run:
+  timeout: 5m # default is 1m
+issues:
+  exclude-rules:
+    - path: contents/kubernetes-operator/controller-runtime/
+      linters:
+        - errcheck
+
+    - path: contents/kubernetes-extensions/kubernetes-scheduler/random-scheduler
+      linters:
+        - errcheck
+
+    - path: contents/kubernetes-operator/client-go/
+      linters:
+        - errcheck

contents/kubernetes-operator/client-go/indexer/main.go

@@ -110,11 +110,11 @@ func exampleWithThreadSafeMap() {
 }
 
 func nameIndexer(obj interface{}) ([]string, error) {
-	switch obj.(type) {
+	switch v := obj.(type) {
 	case string:
-		return []string{obj.(string)}, nil
+		return []string{v}, nil
 	case User:
-		return []string{obj.(User).Name}, nil
+		return []string{v.Name}, nil
 	default:
 		return []string{}, errors.New("nameIndexer error")
 	}

contents/kubernetes-operator/client-go/listerwatcher/README.md

@@ -120,19 +120,17 @@ Code: You can get the event through `w.ResultChan()`. The example is simplified
 	}
 loop:
 	for {
-		select {
-		case event, ok := <-w.ResultChan():
-			if !ok {
-				break loop
-			}
-
-			meta, err := meta.Accessor(event.Object)
-			if err != nil {
-				continue
-			}
-			resourceVersion := meta.GetResourceVersion()
-			klog.Infof("event: %s, resourceVersion: %s", event.Type, resourceVersion)
+		event, ok := <-w.ResultChan()
+		if !ok {
+			break loop
 		}
+
+		meta, err := meta.Accessor(event.Object)
+		if err != nil {
+			continue
+		}
+		resourceVersion := meta.GetResourceVersion()
+		klog.Infof("event: %s, resourceVersion: %s", event.Type, resourceVersion)
 	}
 ```
 

contents/kubernetes-operator/client-go/listerwatcher/main.go

@@ -70,18 +70,16 @@ func main() {
 	}
 loop:
 	for {
-		select {
-		case event, ok := <-w.ResultChan():
-			if !ok {
-				break loop
-			}
+		event, ok := <-w.ResultChan()
+		if !ok {
+			break loop
+		}
 
-			meta, err := meta.Accessor(event.Object)
-			if err != nil {
-				continue
-			}
-			resourceVersion := meta.GetResourceVersion()
-			klog.Infof("event: %s, resourceVersion: %s", event.Type, resourceVersion)
+		meta, err := meta.Accessor(event.Object)
+		if err != nil {
+			continue
 		}
+		resourceVersion := meta.GetResourceVersion()
+		klog.Infof("event: %s, resourceVersion: %s", event.Type, resourceVersion)
 	}
 }

doc/doc.go

@@ -2,7 +2,6 @@ package doc
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 )
@@ -103,7 +102,7 @@ func (m *MarkDownDoc) WriteTable(t *Table) *MarkDownDoc {
 }
 
 func (m *MarkDownDoc) Export(filename string) error {
-	return ioutil.WriteFile(filename, []byte(m.builder.String()), os.ModePerm)
+	return os.WriteFile(filename, []byte(m.builder.String()), os.ModePerm)
 }
 
 func (m *MarkDownDoc) GetLink(desc, url string) string {