How to enable hot reload in your Gin project

Gin is one of the fastest frameworks in the Go world. However, there is one feature missing in Gin is hot realod. So that in this blog I can show you how can you enable hot reaload feature in your Gin project.

Suppose this is your main.go fie

package main

import (
    "fmt"
    "net/http"
    "github.com/gin-gonic/gin"
)

func successResponse(data interface{}) gin.H {
    return gin.H{
        "status": "success",
        "data": data,
    }
}

func successResponseWithMessageAndCode(data interface{}, message string, code int,c *gin.Context) {
    c.JSON(code, gin.H{
        "status": "success",
        "data": data,
        "message": message,
    })
}

func main() {
    r := gin.Default()
    fmt.Println("Hello World")
    r.GET("/", func(c *gin.Context) {
        data:= map[string]interface{}{
            "message": "Hello World",
        }
        successResponseWithMessageAndCode(data, "Success", http.StatusOK, c)
    })

    r.GET("/hello", func(c *gin.Context) {
        c.JSON(http.StatusOK, gin.H{
            "message": "Hello World",
        })
    })

    r.Run("localhost:8080")

}

So we can use Air (https://github.com/air-verse/air) - Live reload for your Go apps

Install Air by using this command 👇

go install github.com/air-verse/air@latest

Then add .air.toml file using this command

air init

If the air command is not found, it might be because the Go bin directory is not in your PATH

In that case I’m using fish terminal

First, let's find out where Go installs binaries. Run this command:

echo $GOPATH/bin

If $GOPATH is not set, the default location is usually ~/go/bin.

Now, let's add this directory to your PATH in Fish. Open your Fish configuration file:

nano ~/.config/fish/config.fish

Add the following line to the file:

set -gx PATH $PATH $GOPATH/bin

If $GOPATH is not set, use the full path, like:

set -gx PATH $PATH ~/go/bin

Save the file and exit the editor.
Reload your Fish configuration:

 ~/.config/fish/config.fish

Now try running air again:

air

If you are using bash terminal you have to edit your .~/bashrc file.

Now edit .air.toml file

root = "."
tmp_dir = "tmp"

[build]
cmd = "go build -o ./tmp/main ."
bin = "tmp/main"
full_bin = "APP_ENV=dev APP_USER=air ./tmp/main"
include_ext = ["go", "tpl", "tmpl", "html"]
exclude_dir = ["assets", "tmp", "vendor"]
include_dir = []
exclude_file = []
log = "air.log"
delay = 1000 # ms
stop_on_error = true
send_interrupt = false
kill_delay = 500 # ms

[log]
time = false

[color]
main = "magenta"
watcher = "cyan"
build = "yellow"
runner = "green"

[misc]
clean_on_exit = true

Ensure your Gin application listens on localhost instead of just :8080 for better hot-reload behavior

r.Run("localhost:8080")

And now instead of run go run main.go , just run air and then see the magic.