Pino Preview 🌲

Interactive Web Viewer for Structured Logs

This is a utility web app for near-real-time previewing of structured JSON logs. It is designed to consume output from applications which use the pino library format for logs.

The utility runs on Node.js, and uses websockets to stream log information to a locally running web interface.

Disclaimer

Note: This is experimental software which may change at any time under development, and should not be relied on for critical use cases.

Note: For security reasons, never run this software against untrusted or potentially malicious input.

Installation

Publishing this package in the npmjs.com registry is currently work-in-progress. In the meanwhile, you can install the package directly from GitHub.

Using NPM

npm install --global "git://github.com/aarokorhonen/pino-preview#release/latest-experimental"

Using Yarn

yarn global add "git://github.com/aarokorhonen/pino-preview#release/latest-experimental"

Usage

This app provides a CLI command called pino-preview which consumes input from the stdin stream. To use it, setup a pipe for the log-producing app (use cat or tail -f if your logs are in a file). For example:

./run-your-app.sh | pino-preview

By default, the app will be served at http://localhost:3001. This can be modified by specifying the PORT environment variable. Use the --open flag to automatically open the web app in your default browser.

Using the sidebar controls, you can filter the log entry view by free text search, log level, timestamp, or by the package field of JSON objects.

As long as you remain scrolled to the bottom of the log panel, the view will auto-follow to scroll down to new log entries as they appear.

For convenience, this app also forwards stdin to stdout, you can also see all log entries in your terminal in addition to the web interface. You can also pipe them to other utilities (such as pino-pretty). For example, a complete usage might be:

./run-your-app.sh | pino-preview --open | pino-pretty