Make HTTP middleware easier to use

appengine/cmd/cron/ui/common.go

Index: appengine/cmd/cron/ui/common.go
diff --git a/appengine/cmd/cron/ui/common.go b/appengine/cmd/cron/ui/common.go
index 4e21ca07d7957556f9da77dd089fd1617bdc12f5..b603fe8e355097b421bd9091130672cdad6338ed 100644
--- a/appengine/cmd/cron/ui/common.go
+++ b/appengine/cmd/cron/ui/common.go
@@ -1,61 +1,59 @@
 // 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 ui implements request handlers that serve user facing HTML pages.
 package ui
 
 import (
 	"strings"
 
-	"github.com/julienschmidt/httprouter"
 	"golang.org/x/net/context"
 	"google.golang.org/appengine"
 
 	"github.com/luci/gae/service/info"
 
 	"github.com/luci/luci-go/server/auth"
 	"github.com/luci/luci-go/server/auth/xsrf"
-	"github.com/luci/luci-go/server/middleware"
+	"github.com/luci/luci-go/server/router"
 	"github.com/luci/luci-go/server/templates"
 
 	"github.com/luci/luci-go/appengine/cmd/cron/engine"
 )
 
 // Config is global configuration of UI handlers.
 type Config struct {
 	Engine        engine.Engine
 	TemplatesPath string // path to templates directory deployed to GAE
 }
 
 // InstallHandlers adds HTTP handlers that render HTML pages.
-func InstallHandlers(r *httprouter.Router, base middleware.Base, cfg Config) {
+func InstallHandlers(r *router.Router, base router.MiddlewareChain, cfg Config) {
 	tmpl := prepareTemplates(cfg.TemplatesPath)
 
-	wrap := func(h middleware.Handler) httprouter.Handle {
-		h = auth.Authenticate(h)
-		h = templates.WithTemplates(h, tmpl)
-		h = middleware.WithContextValue(h, configContextKey(0), &cfg)
-		return base(h)
-	}
+	m := append(base, func(c *router.Context, next router.Handler) {
+		c.Context = context.WithValue(c.Context, configContextKey(0), &cfg)
+		next(c)
+	}, templates.WithTemplates(tmpl), auth.Authenticate)
 
-	r.GET("/", wrap(indexPage))
-	r.GET("/jobs/:ProjectID", wrap(projectPage))
-	r.GET("/jobs/:ProjectID/:JobID", wrap(jobPage))
-	r.GET("/jobs/:ProjectID/:JobID/:InvID", wrap(invocationPage))
+	r.GET("/", m, indexPage)
+	r.GET("/jobs/:ProjectID", m, projectPage)
+	r.GET("/jobs/:ProjectID/:JobID", m, jobPage)
+	r.GET("/jobs/:ProjectID/:JobID/:InvID", m, invocationPage)
 
 	// All POST forms must be protected with XSRF token.
-	r.POST("/actions/runJob/:ProjectID/:JobID", wrap(xsrf.WithTokenCheck(runJobAction)))
-	r.POST("/actions/pauseJob/:ProjectID/:JobID", wrap(xsrf.WithTokenCheck(pauseJobAction)))
-	r.POST("/actions/resumeJob/:ProjectID/:JobID", wrap(xsrf.WithTokenCheck(resumeJobAction)))
-	r.POST("/actions/abortInvocation/:ProjectID/:JobID/:InvID", wrap(xsrf.WithTokenCheck(abortInvocationAction)))
+	mxsrf := append(m, xsrf.WithTokenCheck)
+	r.POST("/actions/runJob/:ProjectID/:JobID", mxsrf, runJobAction)
+	r.POST("/actions/pauseJob/:ProjectID/:JobID", mxsrf, pauseJobAction)
+	r.POST("/actions/resumeJob/:ProjectID/:JobID", mxsrf, resumeJobAction)
+	r.POST("/actions/abortInvocation/:ProjectID/:JobID/:InvID", mxsrf, abortInvocationAction)
 }
 
 type configContextKey int
 
 // config returns Config passed to InstallHandlers.
 func config(c context.Context) *Config {
 	cfg, _ := c.Value(configContextKey(0)).(*Config)
 	if cfg == nil {
 		panic("impossible, configContextKey is not set")
 	}