Go Programming Cookbook
Over 85 recipes to build modular, readable, and testable Golang applications across various domains, 2nd Edition
Aaron Torres
- 434 Seiten
- English
- ePUB (handyfreundlich)
- Über iOS und Android verfügbar
Go Programming Cookbook
Over 85 recipes to build modular, readable, and testable Golang applications across various domains, 2nd Edition
Aaron Torres
Über dieses Buch
Tackle the trickiest of problems in Go programming with this practical guide
Key Features
- Develop applications for different domains using modern programming techniques
- Tackle common problems when it comes to parallelism, concurrency, and reactive programming in Go
- Work with ready-to-execute code based on the latest version of Go
Book Description
Go (or Golang) is a statically typed programming language developed at Google. Known for its vast standard library, it also provides features such as garbage collection, type safety, dynamic-typing capabilities, and additional built-in types. This book will serve as a reference while implementing Go features to build your own applications.
This Go cookbook helps you put into practice the advanced concepts and libraries that Golang offers. The recipes in the book follow best practices such as documentation, testing, and vendoring with Go modules, as well as performing clean abstractions using interfaces. You'll learn how code works and the common pitfalls to watch out for. The book covers basic type and error handling, and then moves on to explore applications, such as websites, command-line tools, and filesystems, that interact with users. You'll even get to grips with parallelism, distributed systems, and performance tuning.
By the end of the book, you'll be able to use open source code and concepts in Go programming to build enterprise-class applications without any hassle.
What you will learn
- Work with third-party Go projects and modify them for your use
- Write Go code using modern best practices
- Manage your dependencies with the new Go module system
- Solve common problems encountered when dealing with backend systems or DevOps
- Explore the Go standard library and its uses
- Test, profile, and fine-tune Go applications
Who this book is for
If you're a web developer, programmer, or enterprise developer looking for quick solutions to common and not-so-common problems in Go programming, this book is for you. Basic knowledge of the Go language is assumed.
Häufig gestellte Fragen
Information
- Initializing, storing, and passing http.Client structures
- Writing a client for a REST API
- Executing parallel and async client requests
- Making use of OAuth2 clients
- Implementing an OAuth2 token storage interface
- Wrapping a client in added functionality and function composition
- Understanding GRPC clients
- Using twitchtv/twirp for RPC
Technical requirements
- Download and install Go 1.12.6 or higher on youroperatingsystem athttps://golang.org/doc/install.
- Open a Terminal or console application, create a project directory such as ~/projects/go-programming-cookbook, and navigate to this directory. All code will be run and modified from this directory.
- Clone the latest code into~/projects/go-programming-cookbook-original and optionally work from that directory rather than typing the examples manually, as follows:
$ git clone [email protected]:PacktPublishing/Go-Programming-Cookbook-Second-Edition.git go-programming-cookbook-original
Initializing, storing, and passing http.Client structures
How to do it...
- From your Terminal or console application, create a new directory called ~/projects/go-programming-cookbook/chapter7/client, and navigate to this directory.
- Run the following command:
$ go mod init github.com/PacktPublishing/Go-Programming-Cookbook-Second-Edition/chapter7/client
module github.com/PacktPublishing/Go-Programming-Cookbook-Second-Edition/chapter7/client
- Copy tests from~/projects/go-programming-cookbook-original/chapter7/client, or use this as an exercise to write some code of your own!
- Create a file called client.go with the following content:
package client
import (
"crypto/tls"
"net/http"
)
// Setup configures our client and redefines
// the global DefaultClient
func Setup(isSecure, nop bool) *http.Client {
c := http.DefaultClient
// Sometimes for testing, we want to
// turn off SSL verification
if !isSecure {
c.Transport = &http.Transport{
TLSClientConfig: &tls.Config{
InsecureSkipVerify: false,
},
}
}
if nop {
c.Transport = &NopTransport{}
}
http.DefaultClient = c
return c
}
// NopTransport is a No-Op Transport
type NopTransport struct {
}
// RoundTrip Implements RoundTripper interface
func (n *NopTransport) RoundTrip(*http.Request)
(*http.Response, error) {
// note this is an uninitialized Response
// if you're looking at headers and so on.
return &http.Response{StatusCode: http.StatusTeapot}, nil
}
- Create a file called exec.go with the following content:
package client
import (
"fmt"
"net/http"
)
// DoOps takes a client, then fetches
// google.com
func DoOps(c *http.Client) error {
resp, err := c.Get("http://www.google.com")
if err != nil {
return err
}
fmt.Println("results of DoOps:", resp.StatusCode)
return nil
}
// DefaultGetGolang uses the default client
// to get golang.org
func DefaultGetGolang() error {
resp, err := http.Get("https://www.golang.org")
if err != nil {
return err
}
fmt.Println("results of DefaultGetGolang:",
resp.StatusCode)
return nil
}
- Create a file called store.go with the following content:
package client
import (
"fmt"
"net/http"
)
// Controller embeds an http.Client
// and uses it internally
type Controller struct {
*http.Client
}
// DoOps with a controller object
func (c *Controller) DoOps() error {
resp, err := c.Client.Get("http://www.google.com")
if err != nil {
return err
}
fmt.Println("results of client.DoOps", resp.StatusCode)
return nil
}
- Create a new directory called example and navigate to it.
- Create a file namedmain.gowith the following content:
package main
import "github.com/PacktPublishing/
Go-Programming-Cookbook-Second-Edition/
chapter7/client"
func main() {
// secure and op!
cli := client.Setup(true, false)
if err := client.DefaultGetGolang(); err != nil {
panic(err)
}
if err := client.DoOps(cli); err != nil {
panic(err)
}
c := client.Controller{Client: cli}
if err := c.DoOps(); err != nil {
panic(err)
}
// secure and noop
// also modifies default
client.Setup(true, true)
if err := client.DefaultGetGolang(); err != nil {
panic(err)
}
}
- Run go run main.go.
- You may also run the following command:
$ go build
$ ./example
$ go run main.go
results of DefaultGetGolang: 200
results of DoOps: 200
results of client.DoOps 200
results of DefaultGetGolang: 418
- If you copied or wrote your own tests, go up one directory and run go test. Ensure that all the tests pass.