Book Image

Mastering Go - Second Edition

By : Mihalis Tsoukalos
Book Image

Mastering Go - Second Edition

By: Mihalis Tsoukalos

Overview of this book

Often referred to (incorrectly) as Golang, Go is the high-performance systems language of the future. Mastering Go, Second Edition helps you become a productive expert Go programmer, building and improving on the groundbreaking first edition. Mastering Go, Second Edition shows how to put Go to work on real production systems. For programmers who already know the Go language basics, this book provides examples, patterns, and clear explanations to help you deeply understand Go’s capabilities and apply them in your programming work. The book covers the nuances of Go, with in-depth guides on types and structures, packages, concurrency, network programming, compiler design, optimization, and more. Each chapter ends with exercises and resources to fully embed your new knowledge. This second edition includes a completely new chapter on machine learning in Go, guiding you from the foundation statistics techniques through simple regression and clustering to classification, neural networks, and anomaly detection. Other chapters are expanded to cover using Go with Docker and Kubernetes, Git, WebAssembly, JSON, and more. If you take the Go programming language seriously, the second edition of this book is an essential guide on expert techniques.
Table of Contents (20 chapters)
Title Page

Testing an HTTP server with a database backend

In this section, you are going to see how to test a database server, which in this case is going to be a PostgreSQL server that works with an HTTP server written in Go. This is a special situation because you will have to get your database data in order to be able to test the correctness of the HTTP server.

For the purposes of this section, I am going to show two Go files named webServer.go and webServer_test.go. Before executing the code, you will need to download the Go package that will help you to work with PostgreSQL from Go, which requires the execution of the following command:

$ go get github.com/lib/pq
  

The Go code of webServer.go is as follows:

package main 
 
import ( 
    "database/sql" 
    "fmt" 
    _ "github.com/lib/pq" 
    "net/http" 
    "os" 
    "time&quot...