How to use @google-cloud/logging - 10 common examples

async function listLogEntries(logName) {
  // [START logging_list_log_entries]
  // 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);

  // List the most recent entries for a given log
  // See
  // https://googlecloudplatform.github.io/google-cloud-node/#/docs/logging/latest/logging?method=getEntries
  const [entries] = await log.getEntries();
  console.log('Logs:');
  entries.forEach(entry => {
    const metadata = entry.metadata;
    console.log(`${metadata.timestamp}:`, metadata[metadata.payload]);

// This makes the logs appear in the same place as console.log()
// invocations from Cloud Functions
const METADATA = {
  resource: {
    type: "cloud_function",
    labels: {
      function_name: "CustomMetrics",
      region: "us-central1"
    }
  },
  severity: "DEBUG"
};

// The Logging instance detects the project ID from the environment
// automatically.
const logging = new Logging();
const log = logging.log(LOG_NAME);

export enum Level {
  ALL = 0,
  DEBUG = 1,
  WARN = 2,
  ERROR = 3,
  NONE = 4
}

let LOG_LEVEL = Level.ALL;
export function setLogLevel(level: Level) {
  LOG_LEVEL = level;
}

export function debug(message: any, ...args: any[]) {

async function listSinks() {
  // [START logging_list_sinks]
  // Imports the Google Cloud client library
  const {Logging} = require('@google-cloud/logging');

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

  // See
  // https://googlecloudplatform.github.io/google-cloud-node/#/docs/logging/latest/logging?method=getSinks
  const [sinks] = await logging.getSinks();
  console.log('Sinks:');
  sinks.forEach(sink => {
    console.log(sink.name);
    console.log(`  Destination: ${sink.metadata.destination}`);
    console.log(`  Filter: ${sink.metadata.filter}`);
  });

  // [END logging_list_sinks]
}

function getLogger() {
  //  Return the logger object for writing logs.  Create it if necessary.
  if (!loggingLog) { // eslint-disable-next-line global-require
    loggingLog = require('@google-cloud/logging')(credentials)
      .log(logName, { removeCircular: true }); //  Mark circular refs by [Circular]
    console.log('created_logger');
  }
  return loggingLog;
}

async function listLogEntriesAdvanced(filter, pageSize, orderBy) {
  // [START logging_list_log_entries_advanced]
  // Imports the Google Cloud client library
  const {Logging} = require('@google-cloud/logging');

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

  /**
   * TODO(developer): Uncomment the following lines to run the code.
   *
   * Filter results, e.g. "severity=ERROR"
   * See https://cloud.google.com/logging/docs/view/advanced_filters for more
   * filter information.
   */
  // const filter = 'severity=ERROR';
  // const pageSize = 5;
  // const orderBy = 'timestamp';

  const options = {
    filter: filter,
    pageSize: pageSize,
    orderBy: orderBy,

async function createSink(sinkName, bucketName, filter) {
  // [START logging_create_sink]
  // Imports the Google Cloud client libraries
  const {Logging} = require('@google-cloud/logging');
  const {Storage} = require('@google-cloud/storage');

  // Creates clients
  const logging = new Logging();
  const storage = new Storage();

  /**
   * TODO(developer): Uncomment the following lines to run the code.
   */
  // const sinkName = 'Name of your sink, e.g. my-sink';
  // const bucketName = 'Desination bucket, e.g. my-bucket';
  // const filter = 'Optional log filer, e.g. severity=ERROR';

  // The destination can be a Cloud Storage bucket, a Cloud Pub/Sub topic,
  // or a BigQuery dataset. In this case, it is a Cloud Storage Bucket.
  // See https://cloud.google.com/logging/docs/api/tasks/exporting-logs for
  // information on the destination format.
  const destination = storage.bucket(bucketName);
  const sink = logging.sink(sinkName);

async function quickstart(
  projectId = 'YOUR_PROJECT_ID', // Your Google Cloud Platform project ID
  logName = 'my-log' // The name of the log to write to
) {
  // Creates a client
  const logging = new Logging({projectId});

  // Selects the log to write to
  const log = logging.log(logName);

  // The data to write to the log
  const text = 'Hello, world!';

  // The metadata associated with the entry
  const metadata = {
    resource: {type: 'global'},
  };

  // Prepares a log entry
  const entry = log.entry(metadata, text);

  // Writes the log entry

async function writeLogEntry(logName) {
  // [START logging_write_log_entry]
  // 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 to write to, e.g. my-log';

  const log = logging.log(logName);

  // Modify this resource to match a resource in your project
  // See
  // https://cloud.google.com/logging/docs/api/ref_v2beta1/rest/v2beta1/MonitoredResource
  const resource = {
    // This example targets the "global" resource for simplicity
    type: 'global',
  };

// automatically.
  let emitRequestLog;
  if (env !== GCPEnv.APP_ENGINE && env !== GCPEnv.CLOUD_FUNCTIONS) {
    const loggingBunyanReq = new LoggingBunyan(options);
    const requestLogger = bunyan.createLogger({
      name: options.logName!,
      streams: [loggingBunyanReq.stream(options.level as types.LogLevel)],
    });
    emitRequestLog = (httpRequest: HttpRequest, trace: string) => {
      requestLogger.info({[LOGGING_TRACE_KEY]: trace, httpRequest});
    };
  }

  return {
    logger,
    mw: commonMiddleware.express.makeMiddleware(
      projectId,
      makeChildLogger,
      emitRequestLog
    ),
  };

  function makeChildLogger(trace: string) {
    return logger.child({[LOGGING_TRACE_KEY]: trace}, true /* simple child */);
  }
}

async function main() {
  const logging = new Logging();
  console.dir(logging);
}
main();