iris/_examples/routing/subdomains/single/main.go

// Package main register static subdomains, simple as parties, check ./hosts if you use windows
package main

import (
	"github.com/kataras/iris/v12"
)

func main() {
	app := iris.New()

	// Subdomain method is just another Party.
	admin := app.Subdomain("admin")
	{
		// admin.mydomain.com
		admin.Get("/", func(c iris.Context) {
			c.Writef("INDEX FROM admin.mydomain.com")
		})
		// admin.mydomain.com/hey
		admin.Get("/hey", func(c iris.Context) {
			c.Writef("HEY FROM admin.mydomain.com/hey")
		})
		// admin.mydomain.com/hey2
		admin.Get("/hey2", func(c iris.Context) {
			c.Writef("HEY SECOND FROM admin.mydomain.com/hey")
		})
	}

	// mydomain.com
	app.Get("/", func(c iris.Context) {
		c.Writef("INDEX FROM no-subdomain hey")
	})

	// mydomain.com/hey
	app.Get("/hey", func(c iris.Context) {
		c.Writef("HEY FROM no-subdomain hey")
	})

	// http://admin.mydomain.com
	// http://admin.mydomain.com/hey
	// http://admin.mydomain.com/hey2
	// http://mydomain.com
	// http://mydomain.com/hey
	app.Listen("mydomain.com:80") // for beginners: look ../hosts file
}