remove deprecated use of ioutil (#5205)

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

Signed-off-by: Jörn Friedrich Dreyer <jfd@butonic.de>

ocis-pkg/ldap/ldap.go

@@ -3,7 +3,6 @@ package ldap
 import (
 	"crypto/x509"
 	"errors"
-	"io/ioutil"
 	"os"
 	"strings"
 	"time"
@@ -39,7 +38,7 @@ func WaitForCA(log log.Logger, insecure bool, caCert string) error {
 			// Check if this actually is a CA cert. We need to retry here as well
 			// as the file might exist already, but have no contents yet.
 			certs := x509.NewCertPool()
-			pemData, err := ioutil.ReadFile(caCert)
+			pemData, err := os.ReadFile(caCert)
 			if err != nil {
 				log.Debug().Err(err).Str("LDAP CACert", caCert).Msg("Error reading CA")
 			} else if !certs.AppendCertsFromPEM(pemData) {

ocis-pkg/log/logrus_wrapper.go

@@ -1,7 +1,7 @@
 package log
 
 import (
-	"io/ioutil"
+	"io"
 
 	"github.com/rs/zerolog"
 	"github.com/sirupsen/logrus"
@@ -28,7 +28,7 @@ type LogrusWrapper struct {
 // underlying zerolog via hooks.
 func LogrusWrap(zr zerolog.Logger) *logrus.Logger {
 	lr := logrus.New()
-	lr.SetOutput(ioutil.Discard)
+	lr.SetOutput(io.Discard)
 	lr.SetLevel(logrusLevel(zr.GetLevel()))
 	lr.AddHook(&LogrusWrapper{
 		zeroLog:  &zr,
@@ -52,7 +52,7 @@ func (h *LogrusWrapper) Fire(entry *logrus.Entry) error {
 	return nil
 }
 
-//Convert logrus fields to zerolog
+// Convert logrus fields to zerolog
 func zeroLogFields(fields logrus.Fields) map[string]interface{} {
 	fm := make(map[string]interface{})
 	for k, v := range fields {

ocis-pkg/service/grpc/client.go

@@ -4,7 +4,7 @@ import (
 	"crypto/tls"
 	"crypto/x509"
 	"errors"
-	"io/ioutil"
+	"os"
 	"sync"
 
 	mgrpcc "github.com/go-micro/plugins/v4/client/grpc"
@@ -68,7 +68,7 @@ func Configure(opts ...ClientOption) error {
 			// Note: If caCert is empty we use the system's default set of trusted CAs
 			if options.caCert != "" {
 				certs := x509.NewCertPool()
-				pemData, err := ioutil.ReadFile(options.caCert)
+				pemData, err := os.ReadFile(options.caCert)
 				if err != nil {
 					outerr = err
 					return