reorganization of _examples and add some new examples such as iris+groupcache+mysql+docker

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/routing/subdomains/www/main.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"github.com/kataras/iris/v12"
+)
+
+func newApp() *iris.Application {
+	app := iris.New()
+
+	app.Get("/", info)
+	app.Get("/about", info)
+	app.Get("/contact", info)
+
+	app.PartyFunc("/api/users", func(r iris.Party) {
+		r.Get("/", info)
+		r.Get("/{id:uint64}", info)
+
+		r.Post("/", info)
+
+		r.Put("/{id:uint64}", info)
+	}) /* <- same as:
+	 usersAPI := app.Party("/api/users")
+	 {  // those brackets are just syntactic-sugar things.
+		// This method is rarely used but you can make use of it when you want
+	    // scoped variables to that code block only.
+		usersAPI.Get/Post...
+	 }
+	 usersAPI.Get/Post...
+	*/
+
+	www := app.Party("www.")
+	{
+		// Just to show how you can get all routes and copy them to another
+		// party or subdomain:
+		// Get all routes that are registered so far, including all "Parties" and subdomains:
+		currentRoutes := app.GetRoutes()
+		// Register them to the www subdomain/vhost as well:
+		for _, r := range currentRoutes {
+			www.Handle(r.Method, r.Tmpl().Src, r.Handlers...)
+		}
+
+		// http://www.mydomain.com/hi
+		www.Get("/hi", func(ctx iris.Context) {
+			ctx.Writef("hi from www.mydomain.com")
+		})
+	}
+	// See also the "subdomains/redirect" to register redirect router wrappers between subdomains,
+	// i.e mydomain.com to www.mydomain.com (like facebook does for SEO reasons(;)).
+
+	return app
+}
+
+func main() {
+	app := newApp()
+	// http://mydomain.com
+	// http://mydomain.com/about
+	// http://imydomain.com/contact
+	// http://mydomain.com/api/users
+	// http://mydomain.com/api/users/42
+
+	// http://www.mydomain.com
+	// http://www.mydomain.com/hi
+	// http://www.mydomain.com/about
+	// http://www.mydomain.com/contact
+	// http://www.mydomain.com/api/users
+	// http://www.mydomain.com/api/users/42
+	if err := app.Listen("mydomain.com:80"); err != nil {
+		panic(err)
+	}
+}
+
+func info(ctx iris.Context) {
+	method := ctx.Method()
+	subdomain := ctx.Subdomain()
+	path := ctx.Path()
+
+	ctx.Writef("\nInfo\n\n")
+	ctx.Writef("Method: %s\nSubdomain: %s\nPath: %s", method, subdomain, path)
+}