[milo] Refactor all html knowledge out of backends.

milo/frontend/config.go

-// Copyright 2015 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 frontend
-
-import (
-        "net/http"
-
-        "cloud.google.com/go/datastore"
-        "google.golang.org/appengine"
-
-        "github.com/luci/luci-go/common/logging"
-        "github.com/luci/luci-go/milo/common"
-        "github.com/luci/luci-go/server/router"
-        "github.com/luci/luci-go/server/templates"
-)
-
-// ConfigsHandler renders the page showing the currently loaded set of luci-configs.
-func ConfigsHandler(c *router.Context) {
-        projects, err := common.GetAllProjects(c.Context)
-        if err != nil {
-                common.ErrorPage(
-                        c, http.StatusInternalServerError,
-                        "Error while getting projects: "+err.Error())
-                return
-        }
-        sc, err := common.GetCurrentServiceConfig(c.Context)
-        if err != nil && err != datastore.ErrNoSuchEntity {
-                common.ErrorPage(
-                        c, http.StatusInternalServerError,
-                        "Error while getting service config: "+err.Error())
-                return
-        }
-
-        templates.MustRender(c.Context, c.Writer, "pages/configs.html", templates.Args{
-                "Projects":      projects,
-                "ServiceConfig": sc,
-        })
-}
-
-// UpdateHandler is an HTTP handler that handles configuration update requests.
-func UpdateConfigHandler(ctx *router.Context) {
-        c, h := ctx.Context, ctx.Writer
-        // Needed to access the PubSub API
-        c = appengine.WithContext(c, ctx.Request)
-        projErr := common.UpdateProjectConfigs(c)
-        if projErr != nil {
-                logging.WithError(projErr).Errorf(c, "project update handler encountered error")
-        }
-        settings, servErr := common.UpdateServiceConfig(c)
-        if servErr != nil {
-                logging.WithError(servErr).Errorf(c, "service update handler encountered error")
-        } else {
-                servErr = common.EnsurePubSubSubscribed(c, settings)
-                if servErr != nil {
-                        logging.WithError(servErr).Errorf(
-                                c, "pubsub subscriber handler encountered error")
-                }
-        }
-        if projErr != nil || servErr != nil {
-                h.WriteHeader(http.StatusInternalServerError)
-                return
-        }
-        h.WriteHeader(http.StatusOK)
-}