How to modify the default port of go gin? My 8080 port is in use

Question

When I use gin to test, the port fails to start normally: [ERROR] listen tcp :8080: bind: address already in use When I use the route to modify the port, it still shows that 8080 port is used

func main() {
  //r := gin.Default()
  //r.GET("/ping", func(c *gin.Context) {
  //  c.JSON(http.StatusOK, gin.H{
  //    "message": "pong",
  //  })
  //})
  router := gin.Default()
    router.GET("/hi", func(context *gin.Context) {
        context.String(http.StatusOK, "Hello world!")
    })
    err := router.Run()
    if err != nil {
        panic("[Error] failed to start Gin server due to: " + err.Error())
        return
    }
  router.Run(":9888")
  //r.Run() // listen and serve on 0.0.0.0:8080 (for windows "localhost:8080")
}

How should I modify it

Answer 1

You're calling Run() twice - and the first instance is being called without any address being supplied. So the default port 8080 is being used in this instance. Updating the code to supply the address in the first call, and removing the duplicate call should hopefully resolve this for you.

func main() {
    router := gin.Default()
    router.GET("/hi", func(context *gin.Context) {
        context.String(http.StatusOK, "Hello world!")
    })
    err := router.Run(":9888")
    if err != nil {
        panic("[Error] failed to start Gin server due to: " + err.Error())
        return
    }
}

Answer 2

use environment variable PORT. Thus no need to change code if deployment platform change.

eg, export PORT=8080

gin-gonic/gin/issues/405