1. RESTful API: Hello world

Final result:

Endpoint: [HTTP GET] http://localhost:1200/api/v1/greetings

Response message: {"msg":"Hello world!"}

HTTP response code: 200

Create a project, build, run

• Create a new project folder myapi
• Create controller folder
• Create a file greetings.go inside controller folder
• Write a function Greetings to greetings.go file

package controller

import (
        "net/http"

        "github.com/gin-gonic/gin"

        "github.com/pilinux/gorest/lib/renderer"
)

func Greetings(c *gin.Context) {
        renderer.Render(c, gin.H{"msg": "Hello world!"}, http.StatusOK)
}

---

• Add the router to the main function in main.go file

package main

import (
        "fmt"

        "myapi/controller"

        "github.com/gin-gonic/gin"
        "github.com/pilinux/gorest/lib/middleware"
)

func main() {
        router, err := SetupRouter()
        if err != nil {
                fmt.Println(err)
                return
        }
        err = router.Run(":" + "1200")
        if err != nil {
                fmt.Println(err)
                return
        }
}

// SetupRouter ...
func SetupRouter() (*gin.Engine, error) {
        router := gin.Default()

        router.Use(middleware.CORS())

        // API:v1
        v1 := router.Group("/api/v1/")
        {
                v1.GET("greetings", controller.Greetings)
        }

        return router, nil
}

---

• Create a Go module, build and start the app.

go mod init myapi

go mod tidy -compat=1.17

go build

chmod +x myapi

./myapi

Project file structure

myapi
│--- main.go
│--- go.mod
│--- go.sum
│
└─── controller
│    └--- greetings.go