Cloud Debugger: Node.js Client
This module provides Snapshot Debugger support for Node.js applications. Snapshot Debugger is an open source product that lets you debug your applications in production without stopping or pausing your application.
A Firebase Realtime Database instance is used to store your data.
A comprehensive list of changes in each version may be found in the CHANGELOG.
- Cloud Debugger Node.js Client API Reference
- Cloud Debugger Documentation
- github.com/googleapis/cloud-debug-nodejs
Read more about the client libraries for Cloud APIs, including the older Google APIs Client Libraries, in Client Libraries Explained.
Table of contents:
Quickstart
Before you begin
- Select or create a Cloud Platform project.
- Enable the Cloud Debugger API.
- Set up authentication with a service account so you can access the API from your local workstation.
Installing the client library
npm install @google-cloud/debug-agent
Debugger Agent Settings
To customize the behaviour of the automatic debugger agent, specify options when starting the agent. The following code sample shows how to pass in a subset of the available options.
require('@google-cloud/debug-agent').start({
// .. auth settings ..
// debug agent settings:
allowExpressions: true,
serviceContext: {
service: 'my-service',
version: 'version-1'
},
capture: { maxFrames: 20, maxProperties: 100 }
});
The following options configure the connection to the Firebase database:
- firebaseDbUrl - https://PROJECT_ID-cdbg.firebaseio.com will be used if not provided. where PROJECT_ID is your project ID.
- firebaseKeyPath - Default google application credentials are used if not provided.
See the agent configuration for a list of possible configuration options.
Using the Debugger
Once your application is running, use the Snapshot Debugger CLI or the VSCode extension to debug your application.
Historical note
Version 6.x and 7.x of this agent supported both the now shutdown Cloud
Debugger service (by default) and the
Snapshot Debugger
(Firebase RTDB backend) by setting the useFirebase
flag to true. Version 8.0.0
removed support for the Cloud Debugger service, making the Snapshot Debugger the
default. To note the useFirebase
flag is now obsolete, but still present for
backward compatibility.
Limitations and Requirements
Note: There is a known issue where enabling the agent may trigger memory leaks. See #811
- Privacy issues can be created by setting snapshot conditions that watch expressions evaluated in the context of your application. You may be able to view sensitive user data when viewing the values of variables.
- The debug agent tries to ensure that all conditions and watchpoints you
add are read-only and have no side effects. It catches, and disallows,
all expressions that may have static side effects to prevent accidental
state change. However, it presently does not catch expressions that have
dynamic side-effects. For example,
o.f
looks like a property access, but dynamically, it may end up calling a getter function. We presently do NOT detect such dynamic-side effects. - The root directory of your application needs to contain a
package.json
file.
Samples
Samples are in the samples/
directory. Each sample's README.md
has instructions for running its sample.
Sample | Source Code | Try it |
---|---|---|
App | source code | |
Snippets | source code |
The Cloud Debugger Node.js Client API Reference documentation also contains samples.
Supported Node.js Versions
Our client libraries follow the Node.js release schedule. Libraries are compatible with all current active and maintenance versions of Node.js. If you are using an end-of-life version of Node.js, we recommend that you update as soon as possible to an actively supported LTS version.
Google's client libraries support legacy versions of Node.js runtimes on a best-efforts basis with the following warnings:
- Legacy versions are not tested in continuous integration.
- Some security patches and features cannot be backported.
- Dependencies cannot be kept up-to-date.
Client libraries targeting some end-of-life versions of Node.js are available, and
can be installed through npm dist-tags.
The dist-tags follow the naming convention legacy-(version)
.
For example, npm install @google-cloud/debug-agent@legacy-8
installs client libraries
for versions compatible with Node.js 8.
Versioning
This library follows Semantic Versioning.
This library is considered to be stable. The code surface will not change in backwards-incompatible ways unless absolutely necessary (e.g. because of critical security issues) or with an extensive deprecation period. Issues and requests against stable libraries are addressed with the highest priority.
More Information: Google Cloud Platform Launch Stages
Contributing
Contributions welcome! See the Contributing Guide.
Please note that this README.md
, the samples/README.md
,
and a variety of configuration files in this repository (including .nycrc
and tsconfig.json
)
are generated from a central template. To edit one of these files, make an edit
to its templates in
directory.
License
Apache Version 2.0
See LICENSE