zap-pretty

This module provides a basic log prettifier for the zap logging library. It reads a standard Zap JSON log line:

{"severity":"INFO","time":"2018-12-10T17:06:24.10107832Z","caller":"main.go:45","message":"doing some stuff","count":2}

And formats it to:

The tool receives JSON lines, determines if they seems like a log line of a supported format and pretty print it to standard output.

Support Zap logging formats:

• zap.NewProduction
• zapdriver.NewProduction

Install

Homebrew

brew install maoueh/tap/zap-pretty

Binary

Download the binary package for your platform, the list is available at https://github.com/maoueh/zap-pretty/releases.

Unpack the binary somewhere on your disk and ensure the binary is in a directory included in your $PATH variable.

Source

go install github.com/maoueh/zap-pretty@latest

Note Source installation requires Go 1.16+.

Usage

Simply pipe the output of the CLI tool generating Zap JSON log lines to the zap-pretty tool:

zap_instrumented | zap-pretty

The tool supports Zap standard production format as well as the Zapdriver standard format (for consumption by Google Stackdriver).

Zapdriver

When using the Zapdriver format, those fields are removed by default from the prettified version to reduce the clutter of the logs:

• labels
• serviceContext
• logging.googleapis.com/labels
• logging.googleapis.com/sourceLocation

If you want to see those fields, you can use --all flag:

zap_instrumented | zap-pretty --all

CLI Arguments

• --all - Show all fields of the line, even those filtered out by default for the active logger format (default false).
• --version - Show version information.
• -n - Format JSON as multiline if got more than n elements in data (default 3).

Troubleshoot

No Conversion

By default, when using zap.NewProductionConfig(), all log statements are issued on the /dev/stderr stream. That means that if you plainly do zap_instrumented | zap-pretty, your JSON lines will not be prettified.

Why? Simply because you are actually piping only the stdout stream to zap-pretty but your actual log statements are written on stderr so they never make their way up to zap-pretty.

Ensures that JSON line you are seeing is redirected to standard output, if it works when doing zap_instrumented 2>&1 | zap-pretty, then it means logs are going out to stderr.

You can live like this, but if you want to customize your logs to output to stdout instead, simply perform the following changes:

    return zap.NewProduction()

To:

    config := zap.NewProductionConfig()
    config.OutputPaths = []string{"stdout"}
    config.ErrorOutputPaths = []string{"stdout"}

    return config.Build()

License

MIT License