handler.go

// Copyright 2017 Google Inc. All Rights Reserved.
//
// 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 api

import (
	"errors"
	"fmt"
	"net/http"
	"time"

	"github.com/golang/glog"
	"k8s.io/apiserver/pkg/server/healthz"
	"k8s.io/heapster/events/manager"
)

const (
	// MaxEventsScrapeDelay should be larger than `frequency` command line argument.
	MaxEventsScrapeDelay = 3 * time.Minute
)

func healthzChecker() healthz.HealthzChecker {
	return healthz.NamedCheck("healthz", func(r *http.Request) error {
		if time.Since(manager.LatestScrapeTime) > MaxEventsScrapeDelay {
			msg := fmt.Sprintf(
				"No event batch within %s (latest: %s)",
				MaxEventsScrapeDelay,
				manager.LatestScrapeTime,
			)
			glog.Warning(msg)
			return errors.New(msg)
		}

		return nil
	})
}