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

Former-commit-id: ed635ee95de7160cde11eaabc0c1dcb0e460a620

_examples/auth/hcaptcha/main.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+	"os"
+
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/middleware/hcaptcha"
+)
+
+// Get the following values from: https://dashboard.hcaptcha.com
+// Also, check: https://docs.hcaptcha.com/#localdev to test on local environment.
+var (
+	siteKey   = os.Getenv("HCAPTCHA-SITE-KEY")
+	secretKey = os.Getenv("HCAPTCHA-SECRET-KEY")
+)
+
+func main() {
+	app := iris.New()
+	app.RegisterView(iris.HTML("./templates", ".html"))
+
+	hCaptcha := hcaptcha.New(secretKey)
+	app.Get("/register", registerForm)
+	app.Post("/register", hCaptcha, register) // See `hcaptcha.SiteVerify` for manual validation too.
+
+	app.Logger().Infof("SiteKey = %s\tSecretKey = %s",
+		siteKey, secretKey)
+
+	// GET: http://yourdomain.com/register
+	app.Listen(":80")
+}
+
+func register(ctx iris.Context) {
+	hcaptchaResp, ok := hcaptcha.Get(ctx)
+	if !ok {
+		ctx.StatusCode(iris.StatusUnauthorized)
+		ctx.WriteString("Are you a bot?")
+		return
+	}
+
+	ctx.Writef("Register action here...action was asked by a Human.\nResponse value is: %#+v", hcaptchaResp)
+}
+
+func registerForm(ctx iris.Context) {
+	ctx.ViewData("SiteKey", siteKey)
+	ctx.View("register_form.html")
+}