Hot reload with Go + Air

Introduction

As a tool to hot reload when changing files in Go I would like to use cosmtrek/air.

environment

go: v1.15.3

Project creation

% mkdir sample && cd sample
% go mod init
% go mod init sample

Anything is fine here, but I use gin as a framework.

% go get -u github.com/gin-gonic/gin
% vi main.go

package main

import "github.com/gin-gonic/gin"

func main()  {
  r := gin.Default()
  r.GET("/", func(c *gin.Context) {
    c.JSON(200, gin.H{
      "message": "response",
    })
  })

  r.Run()
}

go run I will start it with go run.

% go run main.go

When you get up, in another window,

% curl http://localhost:8080
{"message":"response"}

Move with air

Introduction

go get -u github.com/cosmtrek/air

% which air
<GOPATH>/go/bin/air

% air -v
  __    _   ___
 / /\  | | | |_)
/_/--\ |_| |_| \_ v1.12.1 // live reload for Go apps, with Go1.14.0

When air comes in, run it with the air command instead of go run.

$ air

Rewrite main.go when it starts.

package main

import "github.com/gin-gonic/gin"

func main()  {
  r := gin.Default()
  r.GET("/", func(c *gin.Context) {
    c.JSON(200, gin.H{
      "message": "It's a response",
    })
  })

  r.Run()
}

% curl http://localhost:8080
{"message":"It's a response"}

I was able to hot reload.