For Node.js applications, plugins are maintained for the popular Winston and Bunyan logging libraries. Winston is a general-purpose library, implementing a variety of log formatters and transports. Bunyan, which is specialized for structured JSON logs, supports log formatting by piping to the Bunyan command line.
You can also use the Logging client library for Node.js directly, or create your own integrations with your preferred logging library. For example, you can use the Pino log framework example.
The Logging agent doesn't have to be installed to use the Winston or Bunyan on a Compute Engine virtual machine (VM) instance.
Before you begin
- Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Cloud Logging API.
-
In the Google Cloud console, on the project selector page, select or create a Google Cloud project.
-
Make sure that billing is enabled for your Google Cloud project.
-
Enable the Cloud Logging API.
- Prepare your environment for Node.js development.
Configure logging
This section describes how to install and configure the plugins for the Winston and Bunyan logging libraries. For Bunyan, information is provided about how to use Bunyan with a Node.js Express application.
You can use other libraries or frameworks. For example, you can use the Pino log framework. For sample code that uses OpenTelemetry to collect metrics and trace data, and the Pino log framework to collect log data, see Generate traces and metrics with Node.js. If you use Pino, then you must implement a mapping between the Pino severity levels and those used by Cloud Logging. For example code, see Mapping Pino Log Levels.
Install and configure the Winston plugin
Cloud Logging provides a plugin for the Winston Node.js Logging library. The Logging plugin for Winston provides a simpler, higher-level layer for working with Logging.
To install and configure the Winston plugin, do the following:
To install the Logging Winston plugin, use npm:
npm install --save @google-cloud/logging-winston winston
Import the plugin and add it to your Winston configuration:
Configure your plugin.
You can customize the behavior of the Winston plugin using the same configuration options supported by the Cloud Logging API Cloud client library for Node.js. These options can be passed in the
options
object passed to the plugin's constructor.
Install and configure the Bunyan plugin
Cloud Logging provides a plugin for the Bunyan Node.js Logging library. The Logging plugin for Bunyan provides a simpler, higher-level layer for working with Logging.
To install and configure the Bunyan plugin, do the following:
To install the Logging Bunyan plugin, use npm:
npm install --save bunyan @google-cloud/logging-bunyan
Import the plugin and add it to your Bunyan configuration:
Configure your plugin.
You can customize the behavior of the Bunyan plugin using the same configuration options supported by the Cloud Logging API Cloud client library for Node.js. These options can be passed in the
options
object passed to the plugin's constructor.
Use Bunyan and Express
You can set up and use Bunyan with Logging in a Node.js Express application.
For more information on installation, see the documentation for the Cloud Logging libraries for Node.js. You can also report issues using the issue tracker.
Write logs with the Cloud Logging client library
For information on using the Cloud Logging client library for Node.js directly, see Cloud Logging Client Libraries.
Run on Google Cloud
For an application to write logs by using the Cloud Logging libraries for Node.js, the
service account for the underlying resource must have the
Logs Writer (roles/logging.logWriter
) IAM role.
Most Google Cloud environments automatically configure the default
service account to have this role.
App Engine
Cloud Logging is automatically enabled for App Engine, and your app's default service account has the IAM permissions by default to write log entries.
To write log entries from your app, we recommend that you use Bunyan or Winston as described on this page.
For more information, see Writing and viewing logs.
Google Kubernetes Engine (GKE)
GKE automatically grants the default service account
the Logs Writer (roles/logging.logWriter
) IAM role.
If you use
Workload Identity Federation for GKE
with this default service account to let workloads access specific
Google Cloud APIs, then no additional configuration is required.
However, if you use Workload Identity Federation for GKE with a
custom IAM service account, then ensure that the custom service
account has the role of Logs Writer (roles/logging.logWriter
).
If needed, you can also use the following command to add the logging.write
access scope when creating the cluster:
gcloud container clusters create example-cluster-name \
--scopes https://www.googleapis.com/auth/logging.write
Compute Engine
When using Compute Engine VM instances, add the cloud-platform
access scope to each instance. When creating a new instance through the
Google Cloud console, you can do this in the Identity and API access section
of the Create Instance panel. Use the Compute Engine default service
account or another service account of your choice, and select
Allow full access to all Cloud APIs in the Identity and API access
section. Whichever service
account you select, ensure that it has been granted the
Logs Writer role in the IAM & Admin section of the
Google Cloud console.
Cloud Run functions
Cloud Run functions grants the Logs Writer role by default.
The Cloud Logging libraries for Node.js can be used without needing to explicitly provide credentials.
Cloud Run functions is configured to use Cloud Logging automatically.
Run locally and elsewhere
To use the Cloud Logging libraries for Node.js outside of Google Cloud, including running the library on your own workstation, on your data center's computers, or on the VM instances of another cloud provider, you must supply your Google Cloud project ID and appropriate service account credentials directly to the Cloud Logging libraries for Node.js.
For existing service accounts, do the following:
Grant the service account the IAM the Logs Writer (
roles/logging.logWriter
) IAM role. For more information on IAM roles, see Access control.
If you don't have a service account, then create one. For information about this process, see Create service accounts.
For general information about the methods that you can use to authenticate, see Terminology: service accounts.
Use Winston:Use Bunyan:
View the logs
In the Google Cloud console, go to the Logs Explorer page:
If you use the search bar to find this page, then select the result whose subheading is Logging.
In the Logs Explorer, you must specify one or more resources, but the resource selection might not be obvious. Here are some tips to help you get started:
If you are deploying your application to App Engine or using the App Engine-specific libraries, set your resource to GAE Application.
If you are deploying your application on Compute Engine, set the resource to GCE VM Instance.
If you are deploying your application on Google Kubernetes Engine, your cluster's logging configuration determines the resource type of the log entries. For a detailed discussion on the Legacy Google Cloud Observability and the Google Cloud Observability Kubernetes Monitoring solutions, and how those options affect the resource type, see Migrating to Google Cloud Observability Kubernetes Monitoring.
If your application is using the Cloud Logging API directly, the resource is dependent on the API and your configuration. For example, in your application, you can specify a resource or use a default resource.
If you don't see any logs in the Logs Explorer, to see all log entries, switch to the advanced query mode and use an empty query.
- To switch to the advanced query mode, click menu (▾) at the top of the Logs Explorer and then select Convert to advanced filter.
- Clear the content that appears in the filter box.
- Click Submit Filter.
You can examine the individual entries to identify your resources.
For additional information, see Using the Logs Explorer.