How to get full server URL from any endpoint handler in Gin - go

Question

I'm creating an endpoint using Go's Gin web framework. I need full server URL in my handler function. For example, if server is running on http://localhost:8080 and my endpoint is /foo then I need http://localhost:8080/foo when my handler is called.
If anyone is familiar with Python's fast API, the Request object has a method url_for(<endpoint_name>) which has the exact same functionality: https://stackoverflow.com/a/63682957/5353128
In Go, I've tried accessing context.FullPath() but that only returns my endpoint /foo and not the full URL. Other than this, I can't find appropriate method in docs: https://pkg.go.dev/github.com/gin-gonic/gin#Context
So is this possible via gin.Context object itself or are there other ways as well? I'm completely new to Go.

Answer 1

c.Request.Host+c.Request.URL.Path should work but the scheme has to be determined.
package main
import (
"fmt"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/foo", func(c *gin.Context) {
fmt.Println("The URL: ", c.Request.Host+c.Request.URL.Path)
})
r.Run(":8080")
}
You can determine scheme which also you may know already. But you can check as follows:
scheme := "http"
if c.Request.TLS != nil {
scheme = "https"
}
If your server is behind the proxy, you can get the scheme by c.Request.Header.Get("X-Forwarded-Proto")

Answer 2

You can get host part localhost:8080 from context.Request.Host and path part /foo from context.Request.URL.String().
package main
import (
"fmt"
"net/http"
"github.com/gin-gonic/gin"
)
func main() {
r := gin.Default()
r.GET("/foo", func(c *gin.Context) {
c.String(http.StatusOK, "bar")
fmt.Println(c.Request.Host+c.Request.URL.String())
})
// Listen and Server in 0.0.0.0:8080
r.Run(":8080")
}
And you can get http protocol version by context.Request.Proto, But it will not determine http or https. you need to get it from your service specifications.