MINOR: go: Use errors.Is() and fs.ErrNotExist instead of os.IsNotExist()

Author: dkorunic

configuration/configuration.go

@@ -17,7 +17,9 @@ package configuration
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
+	"io/fs"
 	"math/rand"
 	"os"
 	"path/filepath"
@@ -223,7 +225,7 @@ func (c *Configuration) Load() error {
 			c.storage = &StorageHCL{}
 		}
 		if err = c.storage.Load(c.HAProxy.DataplaneConfig); err != nil {
-			if os.IsNotExist(err) {
+			if errors.Is(err, fs.ErrNotExist) {
 				log.Warningf("configuration file %s does not exists, creating one", c.HAProxy.DataplaneConfig)
 			} else {
 				return fmt.Errorf("configuration file %s not valid: %w", c.HAProxy.DataplaneConfig, err)

configuration/misc.go

@@ -19,6 +19,7 @@ import (
 	"encoding/base64"
 	"errors"
 	"fmt"
+	"io/fs"
 	"os"
 	"path"
 	"strconv"
@@ -75,7 +76,7 @@ func processExists(pid int) bool {
 
 func fileExists(filename string) bool {
 	info, err := os.Stat(filename)
-	if os.IsNotExist(err) {
+	if errors.Is(err, fs.ErrNotExist) {
 		return false
 	}
 	return !info.IsDir()

configuration/user.go

@@ -16,7 +16,9 @@
 package configuration
 
 import (
+	"errors"
 	"fmt"
+	"io/fs"
 	"os"
 	"strings"
 	"sync"
@@ -134,7 +136,7 @@ func (u *Users) RemoveUser(user types.User) error {
 
 func (u *Users) getUsersFromUsersListSection(filename, userlistSection string) error {
 	// if file doesn't exists
-	if _, err := os.Stat(filename); os.IsNotExist(err) {
+	if _, err := os.Stat(filename); errors.Is(err, fs.ErrNotExist) {
 		return fmt.Errorf("cannot read %s, file does not exist", filename)
 	}
 	p, errP := parser.New(options.Path(filename))