Add IdleConnTimeout to Traefik's http.server settings (#1340)

* Add IdleTimeout setting to http.server

Without such a timeout there is a risk of resource leakage from piling up connections, particularly when exposing Traefik to the Internet.

Set the default to be 180 seconds

* Add IdleConnTimeout to Traefik's http.server settings

Without enforcing a timeout Traefik is susceptible to resource leakage, particularly when deployed as a public facing proxy exposed to the Internet.

Set the default to be 180 seconds

* tweak

* Update configuration.go

* add some documentation for the idletimeout setting

* need to cast idletimeout

* update doc to refect format specifics

server.go

@@ -17,11 +17,10 @@ import (
 	"reflect"
 	"regexp"
 	"sort"
+	"sync"
 	"syscall"
 	"time"
 
-	"sync"
-
 	"github.com/codegangsta/negroni"
 	"github.com/containous/mux"
 	"github.com/containous/traefik/cluster"
@@ -532,9 +531,10 @@ func (server *Server) prepareServer(entryPointName string, router *middlewares.H
 	}
 
 	return &http.Server{
-		Addr:      entryPoint.Address,
-		Handler:   negroni,
-		TLSConfig: tlsConfig,
+		Addr:        entryPoint.Address,
+		Handler:     negroni,
+		TLSConfig:   tlsConfig,
+		IdleTimeout: time.Duration(server.globalConfiguration.IdleTimeout),
 	}, nil
 }