Book Image

Go for DevOps

By : John Doak, David Justice
5 (1)
Book Image

Go for DevOps

5 (1)
By: John Doak, David Justice

Overview of this book

Go is the go-to language for DevOps libraries and services, and without it, achieving fast and safe automation is a challenge. With the help of Go for DevOps, you'll learn how to deliver services with ease and safety, becoming a better DevOps engineer in the process. Some of the key things this book will teach you are how to write Go software to automate configuration management, update remote machines, author custom automation in GitHub Actions, and interact with Kubernetes. As you advance through the chapters, you'll explore how to automate the cloud using software development kits (SDKs), extend HashiCorp's Terraform and Packer using Go, develop your own DevOps services with gRPC and REST, design system agents, and build robust workflow systems. By the end of this Go for DevOps book, you'll understand how to apply development principles to automate operations and provide operational insights using Go, which will allow you to react quickly to resolve system failures before your customers realize something has gone wrong.
Table of Contents (21 chapters)
1
Section 1: Getting Up and Running with Go
10
Section 2: Instrumenting, Observing, and Responding
14
Section 3: Cloud ready Go

Implementing application I/O

CLI applications require a way to understand how you want them to execute. This might include what files to read, what servers to contact, and what credentials to use.

There are a couple of ways to start an application with the parameters it requires:

  • Using the flag package to define command-line flags
  • Using os.Args to read arguments that are not defined

The flag package will help you when you have a command-line argument that has a strict definition. This might be an argument that defines the endpoint for a needed service. The program might want to have a default value for production , but allow an override when doing testing. This is perfect for a flag.

An example might be a program that queries our Quote of the Day (QOTD) server that we created earlier. We might want to have it automatically use our production endpoint unless we specify it to use another address. This might look like this:

qotd

This simply contacts our...