Make HTTP middleware easier to use

appengine/cmd/dm/frontend/init.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 frontend
 
 import (
         "net/http"
 
-        "golang.org/x/net/context"
-
-        "github.com/julienschmidt/httprouter"
         "github.com/luci/luci-go/appengine/cmd/dm/deps"
         "github.com/luci/luci-go/appengine/gaeconfig"
         "github.com/luci/luci-go/appengine/gaemiddleware"
         "github.com/luci/luci-go/appengine/tumble"
         "github.com/luci/luci-go/common/config"
         "github.com/luci/luci-go/common/logging"
         "github.com/luci/luci-go/server/discovery"
-        "github.com/luci/luci-go/server/middleware"
         "github.com/luci/luci-go/server/prpc"
+        "github.com/luci/luci-go/server/router"
 )
 
-func base(h middleware.Handler) httprouter.Handle {
-        newH := func(c context.Context, rw http.ResponseWriter, r *http.Request, p httprouter.Params) {
-                cfg, err := gaeconfig.New(c)
-                switch err {
-                case nil:
-                        c = config.Set(c, cfg)
-                case gaeconfig.ErrNotConfigured:
-                        logging.Warningf(c, "luci-config service url not configured. Configure this at /admin/settings/gaeconfig.")
-                default:
-                        panic(err)
-                }
-                h(c, rw, r, p)
-        }
-        return gaemiddleware.BaseProd(newH)
+func base() []router.Handler {
+        return append(
+                gaemiddleware.BaseProd(),
+                func(c *router.Context) {
+                        cfg, err := gaeconfig.New(c.Context)
+                        switch err {
+                        case nil:
+                                c.Context = config.Set(c.Context, cfg)
+                        case gaeconfig.ErrNotConfigured:
+                                logging.Warningf(c.Context, "luci-config service url not configured. Configure this at /admin/settings/gaeconfig.")
+                        default:
+                                panic(err)
+                        }
+                },
+        )
 }
 
 func init() {
-        router := httprouter.New()
+        r := router.New()
         tmb := tumble.Service{}
 
         svr := prpc.Server{}
         deps.RegisterDepsServer(&svr)
         discovery.Enable(&svr)
 
-        svr.InstallHandlers(router, base)
-        tmb.InstallHandlers(router)
-        gaemiddleware.InstallHandlers(router, base)
+        svr.InstallHandlers(r, base())
+        tmb.InstallHandlers(r)
+        gaemiddleware.InstallHandlers(r, base())
 
-        http.Handle("/", router)
+        http.Handle("/", r)
 }