Add iris#ConfigureHost as an alternative way to interact with the app's hosts.

Former-commit-id: 5f36f44b86b70818c4c0c6ef7c178b550cc4ac46

HISTORY.md

@@ -18,6 +18,64 @@ Developers are not forced to upgrade if they don't really need it. Upgrade whene
 
 **How to upgrade**: Open your command-line and execute this command: `go get -u github.com/kataras/iris`.
 
+# Mo, 31 July 2017 | v8.1.2
+
+Add a `ConfigureHost` function as an alternative way to customize the hosts via `host.Configurator`.
+The first way was to pass `host.Configurator` as optional arguments on `iris.Runner`s built'n functions (`iris#Server, iris#Listener, iris#Addr, iris#TLS, iris#AutoTLS`), example of this can be found [there](https://github.com/kataras/iris/blob/master/_examples/http-listening/notify-on-shutdown).
+
+Example Code:
+
+```go
+package main
+
+import (
+	stdContext "context"
+	"time"
+
+	"github.com/kataras/iris"
+	"github.com/kataras/iris/context"
+	"github.com/kataras/iris/core/host"
+)
+
+func main() {
+	app := iris.New()
+
+	app.Get("/", func(ctx context.Context) {
+		ctx.HTML("<h1>Hello, try to refresh the page after ~10 secs</h1>")
+	})
+
+    app.ConfigureHost(configureHost) // or pass "configureHost" as `app.Addr` argument, same result.
+
+	app.Logger().Info("Wait 10 seconds and check your terminal again")
+	// simulate a shutdown action here...
+	go func() {
+		<-time.After(10 * time.Second)
+		timeout := 5 * time.Second
+		ctx, cancel := stdContext.WithTimeout(stdContext.Background(), timeout)
+		defer cancel()
+		// close all hosts, this will notify the callback we had register
+		// inside the `configureHost` func.
+		app.Shutdown(ctx)
+	}()
+
+	// http://localhost:8080
+	// wait 10 seconds and check your terminal.
+	app.Run(iris.Addr(":8080"), iris.WithoutServerError(iris.ErrServerClosed))
+}
+
+func configureHost(su *host.Supervisor) {
+	// here we have full access to the host that will be created
+	// inside the `app.Run` or `app.NewHost` function .
+	//
+	// we're registering a shutdown "event" callback here:
+	su.RegisterOnShutdown(func() {
+		println("server is closed")
+	})
+	// su.RegisterOnError
+	// su.RegisterOnServe
+}
+```
+
 # Su, 30 July 2017
 
 Greetings my friends, nothing special today, no version number yet.