List log entries

Demonstrates how to list log entries.

Explore further

For detailed documentation that includes this code sample, see the following:

• View and write Cloud Run function logs
• View and write Cloud Run function logs

Code sample

C#

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

private void ListLogEntries(string logId)
{
    var client = LoggingServiceV2Client.Create();
    LogName logName = new LogName(s_projectId, logId);
    ProjectName projectName = new ProjectName(s_projectId);
    var results = client.ListLogEntries(Enumerable.Repeat(projectName, 1), $"logName={logName.ToString()}",
        "timestamp desc", callSettings: _retryAWhile);
    foreach (var row in results)
    {
        Console.WriteLine($"{row.TextPayload.Trim()}");
    }
}

Go

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import (
	"context"
	"fmt"
	"log"
	"time"

	"cloud.google.com/go/logging"
	"cloud.google.com/go/logging/logadmin"
	"google.golang.org/api/iterator"
)

func getEntries(projectID string) ([]*logging.Entry, error) {
	ctx := context.Background()
	adminClient, err := logadmin.NewClient(ctx, projectID)
	if err != nil {
		log.Fatalf("Failed to create logadmin client: %v", err)
	}
	defer adminClient.Close()

	var entries []*logging.Entry
	const name = "log-example"
	lastHour := time.Now().Add(-1 * time.Hour).Format(time.RFC3339)

	iter := adminClient.Entries(ctx,
		// Only get entries from the "log-example" log within the last hour.
		logadmin.Filter(fmt.Sprintf(`logName = "projects/%s/logs/%s" AND timestamp > "%s"`, projectID, name, lastHour)),
		// Get most recent entries first.
		logadmin.NewestFirst(),
	)

	// Fetch the most recent 20 entries.
	for len(entries) < 20 {
		entry, err := iter.Next()
		if err == iterator.Done {
			return entries, nil
		}
		if err != nil {
			return nil, err
		}
		entries = append(entries, entry)
	}
	return entries, nil
}

Java

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

import com.google.api.gax.paging.Page;
import com.google.cloud.logging.LogEntry;
import com.google.cloud.logging.Logging;
import com.google.cloud.logging.Logging.EntryListOption;
import com.google.cloud.logging.LoggingOptions;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.TimeZone;

public class ListLogEntries {

  public static void main(String[] args) throws Exception {
    // TODO(developer): Replace the variable value with valid log name before running the sample
    // or provide it as an argument.
    String logName = args.length > 0 ? args[0] : "test-log";

    try (Logging logging = LoggingOptions.getDefaultInstance().getService()) {

      // When composing a filter, using indexed fields, such as timestamp, resource.type, logName
      // and
      // others can help accelerate the results
      // Full list of indexed fields here:
      // https://cloud.google.com/logging/docs/view/advanced-queries#finding-quickly
      // This sample restrict the results to only last minute to minimize number of API calls
      Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("UTC"));
      calendar.add(Calendar.MINUTE, -1);
      DateFormat rfc3339 = new SimpleDateFormat("yyyy-MM-dd'T'HH:mm:ss.SSS'Z'");
      String logFilter =
          "logName=projects/"
              + logging.getOptions().getProjectId()
              + "/logs/"
              + logName
              + " AND timestamp>=\""
              + rfc3339.format(calendar.getTime())
              + "\"";

      // List all log entries
      Page<LogEntry> entries = logging.listLogEntries(EntryListOption.filter(logFilter));
      while (entries != null) {
        for (LogEntry logEntry : entries.iterateAll()) {
          System.out.println(logEntry);
        }
        entries = entries.getNextPage();
      }
    }
  }
}

Node.js

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

// Imports the Google Cloud client library
const {Logging} = require('@google-cloud/logging');

// Creates a client
const logging = new Logging();

/**
 * TODO(developer): Uncomment the following line to run the code.
 */
// const logName = 'Name of the log from which to list entries, e.g. my-log';

const log = logging.log(logName);

async function printEntryMetadata() {
  // List the most recent entries for a given log
  // See https://googleapis.dev/nodejs/logging/latest/Logging.html#getEntries
  const [entries] = await log.getEntries();
  console.log('Logs:');
  entries.forEach(entry => {
    const metadata = entry.metadata;
    console.log(`${metadata.timestamp}:`, metadata[metadata.payload]);
  });
}
printEntryMetadata();

PHP

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

use Google\Cloud\Logging\LoggingClient;

/**
 * Print the timestamp and entry for the project and logger.
 *
 * @param string $projectId The Google project ID.
 * @param string $loggerName The name of the logger.
 */
function list_entries($projectId, $loggerName)
{
    $logging = new LoggingClient(['projectId' => $projectId]);
    $loggerFullName = sprintf('projects/%s/logs/%s', $projectId, $loggerName);
    $oneDayAgo = date(\DateTime::RFC3339, strtotime('-24 hours'));
    $filter = sprintf(
        'logName = "%s" AND timestamp >= "%s"',
        $loggerFullName,
        $oneDayAgo
    );
    $options = [
        'filter' => $filter,
    ];
    $entries = $logging->entries($options);

    // Print the entries
    foreach ($entries as $entry) {
        /* @var $entry \Google\Cloud\Logging\Entry */
        $entryInfo = $entry->info();
        if (isset($entryInfo['textPayload'])) {
            $entryText = $entryInfo['textPayload'];
        } else {
            $entryPayload = [];
            foreach ($entryInfo['jsonPayload'] as $key => $value) {
                $entryPayload[] = "$key: $value";
            }
            $entryText = '{' . implode(', ', $entryPayload) . '}';
        }
        printf('%s : %s' . PHP_EOL, $entryInfo['timestamp'], $entryText);
    }
}

Python

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

def list_entries(logger_name):
    """Lists the most recent entries for a given logger."""
    logging_client = logging.Client()
    logger = logging_client.logger(logger_name)

    print("Listing entries for logger {}:".format(logger.name))

    for entry in logger.list_entries():
        timestamp = entry.timestamp.isoformat()
        print("* {}: {}".format(timestamp, entry.payload))

Ruby

To learn how to install and use the client library for Logging, see Logging client libraries.

To authenticate to Logging, set up Application Default Credentials. For more information, see Set up authentication for a local development environment.

require "google/cloud/logging"

# log_name = "my_log_name"
logging = Google::Cloud::Logging.new
entries = logging.entries filter: "logName:#{log_name}",
                          max:    1000,
                          order:  "timestamp desc"

entries.each do |entry|
  puts "[#{entry.timestamp}] #{entry.log_name} #{entry.payload.inspect}"
end

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