- Stackdriver Logging for Winston API Reference
- Logging Documentation
Read more about the client libraries for Cloud APIs, including the older Google APIs Client Libraries, in Client Libraries Explained.
Table of contents:
Before you begin
Select or create a Cloud Platform project.
Enable billing for your project.
Enable the Stackdriver Logging API.
Set up authentication with a service account so you can access the API from your local workstation.
For a more detailed Stackdriver Logging setup guide, see https://cloud.google.com/logging/docs/setup/nodejs.
Installing the client library
npm install --save @google-cloud/logging-winston
Using the client library
const winston = ;const LoggingWinston =const loggingWinston = ;const logger = winston;logger;
Creates a Winston logger that streams to Stackdriver Logging
Logs will be written to: "projects/YOUR_PROJECT_ID/logs/winston_log"
const winston = ;const LoggingWinston = ;const logger =transports:logger
Error objects you log at severity
error or higher can automatically be picked up by Stackdriver Error Reporting if you have specified a
serviceContext.service when instantiating a
const loggingWinston =serviceContext:service: 'my-service' // required to report logged errors// to the Google Cloud Error Reporting// consoleversion: 'my-version';
It is an error to specify a
serviceContext but not specify
You may also want to see the @google-cloud/error-reporting module which provides direct access to the Error Reporting API.
Formatting Request Logs
To format your request logs you can provide a
httpRequest property as part of the log metadata you provide to winston. We will treat this as the
HttpRequest message and Stackdriver logging will show this as a request log. Example:
httpRequest property must be a properly formatted
HttpRequest message. (Note: the linked protobuf documentation shows
Correlating Logs with Traces
If you use @google-cloud/trace-agent module, then this module will set the Stackdriver Logging LogEntry
trace property based on the current trace context when available. That correlation allows you to view log entries inline with trace spans in the Stackdriver Trace Viewer. Example:
If you wish to set the LogEntry
trace property with a custom value, then set a winston metadata property for
'logging.googleapis.com/trace', which is exported by this module as
LOGGING_TRACE_KEY. For example:
const winston = ;const LoggingWinston = ;// ...winston;
Specifying default labels in the constructor
You can specify
labels when initiating the logger constructor.
// Creates a Winston Stackdriver Logging clientconst loggingWinston =labels:name: 'some-name'version: '0.1.0';// Writes some log entrieslogger;// you can also put some `labels` when calling the logger function// the `labels` will be merge togetherlogger;
labels will be on the Log Viewer.
Add a prefix to easily identify logs
You can specify a
prefix in the constructor, and that
prefix will be prepended to all logging messages. This can be helpful, for example, to quickly identify logs from different modules in a project.
// Creates a Winston Stackdriver Logging clientconst loggingWinston =prefix: 'some-module';logger;
Samples are in the
samples/ directory. The samples'
has instructions for running the samples.
|Sample||Source Code||Try it|
|Explict Auth Setup||source code|
This library follows Semantic Versioning.
This library is considered to be in beta. This means it is expected to be mostly stable while we work toward a general availability release; however, complete stability is not guaranteed. We will address issues and requests against beta libraries with a high priority.
More Information: Google Cloud Platform Launch Stages
Contributions welcome! See the Contributing Guide.
Apache Version 2.0