plugin/kubernetes : make kubernetes client log in CoreDNS format (#5461)

Signed-off-by: Ondřej Benkovský <ondrej.benkovsky@jamf.com>

plugin/kubernetes/setup.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"errors"
 	"fmt"
-	"os"
 	"strconv"
 	"strings"
 
@@ -15,6 +14,7 @@ import (
 	clog "github.com/coredns/coredns/plugin/pkg/log"
 	"github.com/coredns/coredns/plugin/pkg/upstream"
 
+	"github.com/go-logr/logr"
 	"github.com/miekg/dns"
 	meta "k8s.io/apimachinery/pkg/apis/meta/v1"
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"       // pull this in here, because we want it excluded if plugin.cfg doesn't have k8s
@@ -32,7 +32,7 @@ func init() { plugin.Register(pluginName, setup) }
 
 func setup(c *caddy.Controller) error {
 	// Do not call klog.InitFlags(nil) here.  It will cause reload to panic.
-	klog.SetOutput(os.Stdout)
+	klog.SetLogger(logr.New(&loggerAdapter{log}))
 
 	k, err := kubernetesParse(c)
 	if err != nil {