Merge abb9d470f2a8d475c58bf0c1c8f69822ffe86d01 into 3f27866f806536be319b3e342001dd4e0fb81691

README.md

@@ -58,6 +58,7 @@ Gin is a web framework written in Go (Golang). It features a martini-like API wi
     - [Bind form-data request with custom struct](#bind-form-data-request-with-custom-struct)
     - [Try to bind body into different structs](#try-to-bind-body-into-different-structs)
     - [http2 server push](#http2-server-push)
+	- [Support limiting the number of accepted requests using netutil.LimitListener](#RunLimited)
 - [Testing](#testing)
 - [Users](#users)
 
@@ -1835,6 +1836,29 @@ func main() {
 }
 ```
 
+### RunLimited
+
+Limit the number of accepted requests via [netutils.LimitListener](https://godoc.org/golang.org/x/net/netutil) 
+
+
+[embedmd]:# (examples/run-limited/main.go go)
+```go
+package main
+
+import "github.com/gin-gonic/gin"
+
+const maxConnections = 10
+func main() {
+	r := gin.Default()
+	r.GET("/ping", func(c *gin.Context) {
+		c.JSON(200, gin.H{
+			"message": "pong",
+		})
+	})
+	r.RunLimited(maxConnections, ":80") // listen and serve on 0.0.0.0:8080
+}
+```
+
 ## Testing
 
 The `net/http/httptest` package is preferable way for HTTP testing.

examples/run-limited/main.go

@@ -0,0 +1,14 @@
+package main
+
+import "github.com/gin-gonic/gin"
+
+const maxConnections = 10
+func main() {
+	r := gin.Default()
+	r.GET("/ping", func(c *gin.Context) {
+		c.JSON(200, gin.H{
+			"message": "pong",
+		})
+	})
+	r.RunLimited(maxConnections, ":80") // listen and serve on 0.0.0.0:8080
+}

gin.go

@@ -10,8 +10,10 @@ import (
 	"net/http"
 	"os"
 	"sync"
+	"time"
 
 	"github.com/gin-gonic/gin/render"
+	"golang.org/x/net/netutil"
 )
 
 const (
@@ -288,6 +290,42 @@ func (engine *Engine) Run(addr ...string) (err error) {
 	return
 }
 
+// RunLimited - use netuil.LimitListener to limit the number of inbound accepts
+func (engine *GalapagosEngine) RunLimited(limit int, addr ...string) (err error) {
+	defer func() { debugPrintError(err) }()
+
+	address := resolveAddress(addr)
+	debugPrint("Listening and serving HTTP on %s\n", address)
+
+	// err = http.ListenAndServe(address, engine)
+
+	srv := &http.Server{Addr: address, Handler: engine}
+	address = srv.Addr
+	if address == "" {
+		address = ":http"
+	}
+	ln, err := net.Listen("tcp", address)
+	if err != nil {
+		return err
+	}
+	lnLimited := netutil.LimitListener(tcpKeepAliveListener{ln.(*net.TCPListener)}, limit)
+	return srv.Serve(lnLimited)
+}
+
+type tcpKeepAliveListener struct {
+	*net.TCPListener
+}
+
+func (ln tcpKeepAliveListener) Accept() (net.Conn, error) {
+	tc, err := ln.AcceptTCP()
+	if err != nil {
+		return nil, err
+	}
+	tc.SetKeepAlive(true)
+	tc.SetKeepAlivePeriod(3 * time.Minute)
+	return tc, nil
+}
+
 // RunTLS attaches the router to a http.Server and starts listening and serving HTTPS (secure) requests.
 // It is a shortcut for http.ListenAndServeTLS(addr, certFile, keyFile, router)
 // Note: this method will block the calling goroutine indefinitely unless an error happens.