Make HTTP middleware easier to use

appengine/gaemiddleware/appengine.go

 // Copyright 2015 The LUCI Authors. All rights reserved.
 // Use of this source code is governed under the Apache License, Version 2.0
 // that can be found in the LICENSE file.
 
 package gaemiddleware
 
 import (
         "fmt"
         "net/http"
 
-        "github.com/julienschmidt/httprouter"
         "github.com/luci/gae/service/info"
         "github.com/luci/luci-go/common/logging"
-        "github.com/luci/luci-go/server/middleware"
+        "github.com/luci/luci-go/server/router"
         "golang.org/x/net/context"
 )
 
 var devAppserverBypassFn = func(c context.Context) bool {
         return info.Get(c).IsDevAppServer()
 }
 
-// RequireCron ensures that this handler was run from the appengine 'cron'
+// RequireCron ensures that the request is from the appengine 'cron'
 // service. Otherwise it aborts the request with a StatusForbidden.
 //
 // This middleware has no effect when using 'BaseTest' or when running under
 // dev_appserver.py
-func RequireCron(h middleware.Handler) middleware.Handler {
-        return func(c context.Context, rw http.ResponseWriter, r *http.Request, p httprouter.Params) {
-                if !devAppserverBypassFn(c) {
-                        if r.Header.Get("X-Appengine-Cron") != "true" {
-                                rw.WriteHeader(http.StatusForbidden)
-                                logging.Errorf(c, "request not made from cron")
-                                fmt.Fprint(rw, "error: must be run from cron")
-                                return
-                        }
+func RequireCron(c *router.Context, next router.Handler) {
+        if !devAppserverBypassFn(c.Context) {
+                if c.Request.Header.Get("X-Appengine-Cron") != "true" {
+                        c.Writer.WriteHeader(http.StatusForbidden)
+                        logging.Errorf(c.Context, "request not made from cron")
+                        fmt.Fprint(c.Writer, "error: must be run from cron")
+                        return
                 }
-                h(c, rw, r, p)
         }
+        next(c)
 }
 
-// RequireTaskQueue ensures that this handler was run from the specified
+// RequireTaskQueue ensures that the request is from the specified
 // appengine 'taskqueue' queue. Otherwise it aborts the request with
 // a StatusForbidden.
 //
 // if `queue` is the empty string, than this simply checks that this handler was
 // run from ANY appengine taskqueue.
 //
 // This middleware has no effect when using 'BaseTest' or when running under
 // dev_appserver.py
-func RequireTaskQueue(queue string, h middleware.Handler) middleware.Handler {
-        return func(c context.Context, rw http.ResponseWriter, r *http.Request, p httprouter.Params) {
-                if !devAppserverBypassFn(c) {
-                        qName := r.Header.Get("X-AppEngine-QueueName")
+func RequireTaskQueue(queue string) router.Middleware {
+        return func(c *router.Context, next router.Handler) {
+                if !devAppserverBypassFn(c.Context) {
+                        qName := c.Request.Header.Get("X-AppEngine-QueueName")
                         if qName == "" || (queue != "" && queue != qName) {
-                                rw.WriteHeader(http.StatusForbidden)
-                                logging.Errorf(c, "request made from wrong taskqueue: %q v %q", qName, queue)
-                                fmt.Fprintf(rw, "error: must be run from the correct taskqueue")
+                                c.Writer.WriteHeader(http.StatusForbidden)
+                                logging.Errorf(c.Context, "request made from wrong taskqueue: %q v %q", qName, queue)
+                                fmt.Fprintf(c.Writer, "error: must be run from the correct taskqueue")
                                 return
                         }
                 }
-                h(c, rw, r, p)
+                next(c)
         }
 }