add accesslog+proxy example

_examples/logging/request-logger/accesslog-proxy/main.go

@@ -0,0 +1,86 @@
+/*Package main is a proxy + accesslog example.
+In this example we will make a small proxy which listens requests on "/proxy/+path".
+With two accesslog instances, one for the main application and one for the /proxy/ requests.
+Of cource, you could a single accesslog for the whole application, but for the sake of the example
+let's log them separately.
+
+We will make use of iris.StripPrefix and host.ProxyHandler.*/
+package main
+
+import (
+	"net/url"
+
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/core/host"
+	"github.com/kataras/iris/v12/middleware/accesslog"
+	"github.com/kataras/iris/v12/middleware/recover"
+)
+
+func main() {
+	app := iris.New()
+	app.Get("/", index)
+
+	ac := accesslog.File("access.log")
+	defer ac.Close()
+	ac.Async = true
+	ac.RequestBody = true
+	ac.ResponseBody = true
+	ac.BytesReceived = false
+	ac.BytesSent = false
+
+	app.UseRouter(ac.Handler)
+	app.UseRouter(recover.New())
+
+	proxy := app.Party("/proxy")
+	{
+		acProxy := accesslog.File("proxy_access.log")
+		defer acProxy.Close()
+		acProxy.Async = true
+		acProxy.RequestBody = true
+		acProxy.ResponseBody = true
+		acProxy.BytesReceived = false
+		acProxy.BytesSent = false
+
+		// Unlike Use, the UseRouter method replaces any duplications automatically.
+		// (see UseOnce for the same behavior on Use).
+		// Therefore, this statement removes the parent's accesslog and registers this new one.
+		proxy.UseRouter(acProxy.Handler)
+		proxy.UseRouter(recover.New())
+		proxy.Use(func(ctx iris.Context) {
+			ctx.CompressReader(true)
+			ctx.Next()
+		})
+
+		/* Listen for specific proxy paths:
+		// Listen on "/proxy" for "http://localhost:9090/read-write"
+		proxy.Any("/", iris.StripPrefix("/proxy",
+			newProxyHandler("http://localhost:9090/read-write")))
+		*/
+
+		// You can register an access log only for proxied requests, e.g. proxy_access.log:
+		// proxy.UseRouter(ac2.Handler)
+
+		// Listen for any proxy path.
+		// Proxies the "/proxy/+$path" to "http://localhost:9090/$path".
+		proxy.Any("/{p:path}", iris.StripPrefix("/proxy",
+			newProxyHandler("http://localhost:9090")))
+	}
+
+	// $ go run target/main.go
+	// open new terminal
+	// $ go run main.go
+	app.Listen(":8080")
+}
+
+func index(ctx iris.Context) {
+	ctx.WriteString("OK")
+}
+
+func newProxyHandler(proxyURL string) iris.Handler {
+	target, err := url.Parse(proxyURL)
+	if err != nil {
+		panic(err)
+	}
+	reverseProxy := host.ProxyHandler(target)
+	return iris.FromStd(reverseProxy)
+}