etcd/proxy/grpcproxy/health.go
Gyuho Lee 92f180c574 *: log server-side /health checks
To make it easier to root-cause when /health check fails.
For example, we are using load balancer to health check
each etcd instance, and when one etcd node gets terminated,
it's hard to tell whether etcd "server" was really failing
or client (or load balancer") failed to reach the etcd cluster
which is also failure in load balancer health check.

Signed-off-by: Gyuho Lee <leegyuho@amazon.com>
2020-03-18 11:14:05 -07:00

46 lines
1.3 KiB
Go

// Copyright 2017 The etcd 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 grpcproxy
import (
"context"
"net/http"
"time"
"go.etcd.io/etcd/clientv3"
"go.etcd.io/etcd/etcdserver/api/etcdhttp"
"go.etcd.io/etcd/etcdserver/api/v3rpc/rpctypes"
"go.uber.org/zap"
)
// HandleHealth registers health handler on '/health'.
func HandleHealth(lg *zap.Logger, mux *http.ServeMux, c *clientv3.Client) {
if lg == nil {
lg = zap.NewNop()
}
mux.Handle(etcdhttp.PathHealth, etcdhttp.NewHealthHandler(lg, func() etcdhttp.Health { return checkHealth(c) }))
}
func checkHealth(c *clientv3.Client) etcdhttp.Health {
h := etcdhttp.Health{Health: "false"}
ctx, cancel := context.WithTimeout(c.Ctx(), time.Second)
_, err := c.Get(ctx, "a")
cancel()
if err == nil || err == rpctypes.ErrPermissionDenied {
h.Health = "true"
}
return h
}