Lets Go

This is my first project with Go programming language. In this project I set up an HTTP server with Golang and then test that server with two different ways. In the first case we are using a Golang client, in the second case we are using Grafana k6 testing.

This project is perfect for people who want to start learning Golang.

What did I learn?

• golang files and package structure
• net/http package
• k6 testing

Project structure in Golang

Every Golang project has a go.mod file. This file manages the modules that we import and use in our Golang projects. Remember that module name should be like your github repository address.

module github.com/USERNAME/REPOSITORY

Now we have a CMD which contains all of our Golang application codes. In this folder we have an http module which manages the server handlers and server responses. The other module is server itself that manages the application.

|_ client/
    |_ main.go
|_ cmd/
    |_ http/
        |_ handler/
        |_ response/
    |_ server/
        |_ main.go

Run the project on your local

Clone the project, then run the following command:

go run cmd/server/main.go

And you will get this response:

Server is listening on 127.0.0.1:8080 ...

This command creates a HTTP server for you. Now you can access this server on localhost:8080.

Connect to our server

Grafana k6

What is k6?

Grafana k6 is an open-source load testing tool that makes performance testing easy and productive for engineering teams. k6 is free, developer-centric, and extensible.

Using k6, you can test the reliability and performance of your systems and catch performance regressions and problems earlier. k6 will help you to build resilient and performant applications that scale.

k6 is developed by Grafana Labs and the community.

Now you can test the server with k6 using the following command:

k6 run api/k6/script.js

And results will be something like this:

running (0m23.7s), 00/20 VUs, 46 complete and 8 interrupted iterations
default ✗ [====>---------------------------------] 08/20 VUs  0m23.7s/3m00.0s

     ✓ status is 200

     checks.........................: 100.00% ✓ 97       ✗ 0   
     data_received..................: 18 kB   744 B/s
     data_sent......................: 9.1 kB  384 B/s
     http_req_blocked...............: avg=58.99µs  min=4µs   med=13µs  max=791µs p(90)=20.2µs  p(95)=547.99µs
     http_req_connecting............: avg=36.75µs  min=0s    med=0s    max=630µs p(90)=0s      p(95)=432.79µs
     http_req_duration..............: avg=573.59µs min=159µs med=597µs max=1ms   p(90)=702.4µs p(95)=737.8µs 
       { expected_response:true }...: avg=573.59µs min=159µs med=597µs max=1ms   p(90)=702.4µs p(95)=737.8µs 
     http_req_failed................: 0.00%   ✓ 0        ✗ 105 
     http_req_receiving.............: avg=93.16µs  min=27µs  med=98µs  max=152µs p(90)=115.2µs p(95)=123.39µs
     http_req_sending...............: avg=48.84µs  min=18µs  med=48µs  max=122µs p(90)=57.2µs  p(95)=82.79µs 
     http_req_tls_handshaking.......: avg=0s       min=0s    med=0s    max=0s    p(90)=0s      p(95)=0s      
     http_req_waiting...............: avg=431.58µs min=100µs med=445µs max=823µs p(90)=546.4µs p(95)=579.59µs
     http_reqs......................: 105     4.424716/s
     iteration_duration.............: avg=2s       min=2s    med=2s    max=2.01s p(90)=2.01s   p(95)=2.01s   
     iterations.....................: 46      1.938447/s
     vus............................: 8       min=1      max=8 
     vus_max........................: 20      min=20     max=20

Golang

Or using Goland HTTP Client with the following command:

go run cmd/client/main.go

This script creates a Golang client and sends HTTP requests to our server.

Response status: 202 Accepted
{"Status":"202","Message":"Welcome Home"}
Response status: 202 Accepted
{"Message":"Hello Amir","Time":"2022-08-21T10:52:20.04668+04:30"}