```

#### GKE via Stackdriver Log Viewer

Each GKE cluster's will have many categories of logs collected by Stackdriver.  Logs can be monitored via
the project's [log viewer](https://cloud.google.com/logging/docs/view/overview) and/or the `gcloud logging read`
capability.

The following example grabs the last 10 `kubelet` logs containing the string "cmdAdd" in the log message.

```console

import org.apache.maven.artifact.Artifact;
import org.apache.maven.artifact.versioning.VersionRange;
import org.codehaus.plexus.logging.Logger;

/**
 * Send resolution warning events to the warning log.
 *
 */
@Deprecated
public class WarningResolutionListener implements ResolutionListener {
    private Logger logger;

    public WarningResolutionListener(Logger logger) {
        this.logger = logger;
    }

        cli.logging(request);
        assertTrue(MessageUtils.isColorEnabled());

        MessageUtils.setColorEnabled(true);
        request = new CliRequest(new String[] {"-l", "target/temp/mvn.log"}, null);
        request.workingDirectory = "target/temp";
        cli.cli(request);
        cli.properties(request);
        cli.logging(request);
        assertFalse(MessageUtils.isColorEnabled());

{!> ../../docs_src/background_tasks/tutorial002.py!}
```

////

In obigem Beispiel werden die Nachrichten, *nachdem* die Response gesendet wurde, in die Datei `log.txt` geschrieben.

Wenn im Request ein Query-Parameter enthalten war, wird dieser in einem Hintergrundtask in das Log geschrieben.

Und dann schreibt ein weiterer Hintergrundtask, der in der *Pfadoperation-Funktion* erstellt wird, eine Nachricht unter Verwendung des Pfad-Parameters `email`.

	pilotxds "istio.io/istio/pilot/pkg/xds"
	"istio.io/istio/pkg/log"
)

var configDumpFile string

func readConfigFile(filename string) ([]byte, error) {
	file := os.Stdin
	if filename != "-" {
		var err error
		file, err = os.Open(filename)
		if err != nil {
			return nil, err
		}
	}
	defer func() {
		if err := file.Close(); err != nil {
			log.Errorf("failed to close %s: %s", filename, err)
		}
	}()

 *
 * Using a yubikey device as a SSL key store.
 * https://lauri.võsandi.com/2017/03/yubikey-for-ssh-auth.html
 *
 * Using PKCS11 support in the JDK.
 * https://tersesystems.com/blog/2018/09/08/keymanagers-and-keystores/
 *
 * Install OpenSC separately. On a mac `brew cast install opensc`.
 */
@SuppressSignatureCheck
class YubikeyClientAuth {
  fun run() {

	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"

	"istio.io/istio/istioctl/pkg/cli"
	"istio.io/istio/istioctl/pkg/clioptions"
	"istio.io/istio/istioctl/pkg/util"
	"istio.io/istio/pkg/kube"
	"istio.io/istio/pkg/log"
)

var (
	listenPort     = 0
	controlZport   = 0
	promPort       = 0
	grafanaPort    = 0
	kialiPort      = 0
	jaegerPort     = 0
	zipkinPort     = 0
	skywalkingPort = 0

	bindAddress = ""

	close(target.quitCh)
	if target.updateStmt != nil {
		// FIXME: log returned error. ignore time being.
		_ = target.updateStmt.Close()
	}

	if target.deleteStmt != nil {
		// FIXME: log returned error. ignore time being.
		_ = target.deleteStmt.Close()
	}

	if target.insertStmt != nil {
		// FIXME: log returned error. ignore time being.
		_ = target.insertStmt.Close()
	}

	if err != nil {
		return kubeconfig{}, err
	}
	// Convert to v1 schema which has proper encoding
	fullYaml, err := yaml.Marshal(lcfg)
	if err != nil {
		return kubeconfig{}, err
	}

	// Log with redaction
	if err := api.RedactSecrets(kcfg); err != nil {
		return kubeconfig{}, err
	}
	for _, c := range kcfg.Clusters {
		// Not actually sensitive, just annoyingly verbose.

				z.rebalMeta.PoolStats[poolIdx].Info.EndTime = now
				z.rebalMu.Unlock()

			case <-timer.C:
				traceMsg = fmt.Sprintf("saved at %s", time.Now())
			}

			stopFn := globalRebalanceMetrics.log(rebalanceMetricSaveMetadata, poolIdx, traceMsg)
			err := z.saveRebalanceStats(GlobalContext, poolIdx, rebalSaveStats)
			stopFn(0, err)
			rebalanceLogIf(GlobalContext, err)

			if quit {
				return
			}