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

Reading and writing to files

The most common scenario in DevOps tooling is the need to manipulate files: reading, writing, reformatting, or analyzing the data in those files. These files could be in many formats – JSON, YAML, XML, CSV, and others that are probably familiar to you. They are used to configure both local services and to interact with your cloud network provider.

In this section, we will cover the basics of reading and writing entire files.

Reading local files

Let's start by reading a configuration file on a local disk by using the os.Readfile() function:

data, err := os.ReadFile("path/to/file")

The ReadFile() method reads the location from its function parameter and returns that file's content. That return value is then stored in the data variable. An error is returned if the file cannot be read. For a refresher on errors, see the Handling errors in Go section in Chapter 2, Go Language Essentials.

ReadFile() is a helper function...