David's Blog

A Powerful Process Supervisor Gaper

By David Li on 2023-05-26T15:32:48.952Z

What is Gaper

When developing applications in Golang, it is crucial to ensure that your programs run smoothly, and that they are able to recover from unexpected crashes or restarts. This is where Gaper, a process supervisor for Golang, comes in handy. In this article, we’ll explore Gaper’s features and demonstrate how to use it effectively in your Golang projects.

Gaper is a lightweight and easy-to-use process supervisor designed specifically for Golang applications. It is responsible for managing the lifecycle of your application, as well as monitoring and restarting it in case of failures or crashes.

The key features of Gaper include:

  1. Automatic restarts when the application crashes or exits unexpectedly.
  2. Configurable backoff strategy for restarts to avoid overwhelming the system.
  3. Support for both long-running services and one-off tasks.
  4. Clean shutdown of child processes on termination.
  5. Easy integration with Golang applications, with minimal configuration required.

Getting Started with Gaper

Before diving into examples, make sure you have Golang installed on your system. If not, follow the official installation guide.

To install Gaper, use the following command:

go get -u github.com/maxence-charriere/gaper

This command will download and install Gaper into your $GOPATH.

Using Gaper in Your Golang Application

To use Gaper, you’ll need to create a main. file that will serve as the entry point for your application. This file will include the Gaper package and use its gaper.Run()` function to start your application.

Here’s an example of a simple `main. file:

package main

import (

func main() {

In this example, replace yourapp/cmd with the import path to your application’s main package. The cmd.Execute function should be the entry point for your application, starting all necessary services or tasks.

Configuring Gaper

Gaper provides a variety of configuration options through environment variables. Here are some of the most commonly used options:

  • GAPER_RESTART_DELAY: The initial delay before restarting the application (in milliseconds). Defaults to 1000 (1 second).
  • GAPER_MAX_RESTART_DELAY: The maximum delay before restarting the application (in milliseconds). Defaults to 32000 (32 seconds).
  • GAPER_BACKOFF_FACTOR: The factor by which the restart delay increases on each consecutive failure (geometric progression). Defaults to 2.
  • GAPER_MAX_RETRIES: The maximum number of retries before giving up on restarting the application. Defaults to 10.

For example, to set a custom restart delay and maximum retries, add the following lines to your `main. file:

package main

import (

func main() {
	os.Setenv("GAPER_RESTART_DELAY", "2000")
	os.Setenv("GAPER_MAX_RETRIES", "5")
	// ...

Wrapping Up

Gaper is a powerful and easy-to-use process supervisor for Golang applications that can help you ensure the reliability and resiliency of your programs. By integrating Gaper into your projects, you can automatically restart your applications in case of failures and crashes, and configure the behavior of these restarts using a variety of options.

With Gaper, you can focus on developing your application’s core functionality, knowing that the process supervision is taken care of.

© Copyright 2024 by FriendlyUsers Tech Blog. Built with ♥ by FriendlyUser. Last updated on 2024-02-20.