[milo] Refactor all html knowledge out of backends.

milo/logs/main.go

 // Copyright 2017 The LUCI Authors.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //      http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
 package main
 
 import (
         "fmt"
         "log"
         "net/http"
         "strings"
 
-        "github.com/luci/luci-go/milo/common"
+        "github.com/luci/gae/impl/cloud"
         "github.com/luci/luci-go/server/auth"
         "github.com/luci/luci-go/server/router"
 )
 
+// flexBase returns the basic middleware for use on appengine flex.  Flex does not
+// allow the use of appengine APIs.
+func flexBase() router.MiddlewareChain {
+        // Installs the Info and Datastore services.
+        return router.NewMiddlewareChain(func(c *router.Context, next router.Handler) {
+                c.Context = cloud.UseFlex(c.Context)
+                next(c)
+        })
+}
+
 // Where it all begins!!!
 func main() {
         r := router.New()
 
-        base := common.FlexBase()
+        base := flexBase()
         r.GET("/log/raw/*path", base, rawLog)
 
         // Health check, for the appengine flex environment.
         http.HandleFunc("/_ah/health", healthCheckHandler)
         // And everything else.
         http.Handle("/", r)
 
         log.Print("Listening on port 8080")
         log.Fatal(http.ListenAndServe(":8080", nil))
 }
@@ skipping 32 matching lines @@
                 http.Redirect(c.Writer, c.Request, loginURL, http.StatusTemporaryRedirect)
                 return
         default:
                 fmt.Fprintf(c.Writer, "Encountered error: %s", err.Error())
         }
 }
 
 func healthCheckHandler(w http.ResponseWriter, r *http.Request) {
         fmt.Fprint(w, "ok")
 }