auth: Refactor how authentication methods are passed to server/auth library.

milo/appengine/common/middleware.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 common
 
 import (
         "net/http"
         "strings"
 
@@ skipping 38 matching lines @@
                                 "Analytics":   analytics.Snippet(c),
                                 "RequestID":   info.RequestID(c),
                         }, nil
                 },
                 FuncMap: funcMap,
         }
 }
 
 // Base returns the basic LUCI appengine middlewares.
 func Base() router.MiddlewareChain {
-        methods := auth.Authenticator{
-                &server.OAuth2Method{Scopes: []string{server.EmailScope}},
-                server.CookieAuth,
-                &server.InboundAppIDAuthMethod{},
-        }
-        m := gaemiddleware.BaseProd().Extend(auth.Use(methods), auth.Authenticate)
+        m := gaemiddleware.BaseProd().Extend(auth.Authenticate(&auth.Authenticator{
+                Methods: []auth.Method{
+                        &server.OAuth2Method{Scopes: []string{server.EmailScope}},
+                        server.CookieAuth,
+                        &server.InboundAppIDAuthMethod{},
+                },
+        }))
         m = m.Extend(withRequestMiddleware)
         m = m.Extend(templates.WithTemplates(GetTemplateBundle()))
         return m
 }
 
 // The context key, so that we can embed the http.Request object into
 // the context.
 var requestKey = "http.request"
 
 // WithRequest returns a context with the http.Request object
 // in it.
 func WithRequest(c context.Context, r *http.Request) context.Context {
         return context.WithValue(c, &requestKey, r)
 }
 
 // withRequestMiddleware is a middleware that installs a request into the context.
 // This is used for various things in the default template.
 func withRequestMiddleware(c *router.Context, next router.Handler) {
         c.Context = WithRequest(c.Context, c.Request)
         next(c)
 }
 
 func getRequest(c context.Context) *http.Request {
         if req, ok := c.Value(&requestKey).(*http.Request); ok {
                 return req
         }
         panic("No http.request found in context")
 }