Go GELF Logging Library

Minimal helper package to send application logs to Graylog via GELF while still writing to the standard Go logger.

Overview

This module wraps gopkg.in/aphistic/golf.v0 and exposes a small API for common log levels.

Behavior summary:

• If GELF is configured with SetDefaultConfig, messages are sent to Graylog over UDP.
• Messages are also written to the standard Go logger (log package).
• If GELF is not configured, logging still works locally via the standard logger.

Installation

go get scm.yoorie.de/go-lib/gelf

Quick Start

package main

import (
  "scm.yoorie.de/go-lib/gelf"
)

func main() {
  gelf.SetDefaultConfig("graylog.example.local", 12201,
    map[string]interface{}{
      "service": "billing-api",
      "env":     "prod",
    },
  )

  gelf.Info("service started")
  gelf.Infof("listening on %s", ":8080")
  gelf.Alert("database latency is high")
}

API

Configuration

• SetDefaultConfig(host string, port int, attrs map[string]interface{})

Creates and configures the default GELF logger. Attributes in attrs are attached as default fields to all GELF messages.

Logging Functions

• Debug(msg string)
• Debugf(format string, va ...interface{})
• Info(msg string)
• Infof(format string, va ...interface{})
• Alert(msg string)
• Alertf(format string, va ...interface{})
• Fatal(msg string)
• Fatalf(format string, va ...interface{})

Notes

• Fatal and Fatalf terminate the program by calling log.Fatalf.
• Graylog delivery uses UDP (udp://host:port).
• Calling SetDefaultConfig again replaces the previous client.

Development

Run tests:

go test ./...

Module information is defined in go.mod.

Additional Documentation

• Definition of Done
• Releasing

License

See LICENSE.

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