mirror of
https://gitea.com/Lydanne/buildx.git
synced 2025-10-31 08:03:43 +08:00
108 lines
2.8 KiB
Go
108 lines
2.8 KiB
Go
/*
|
|
*
|
|
* Copyright 2018 gRPC 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 health
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"io"
|
|
"time"
|
|
|
|
"google.golang.org/grpc"
|
|
"google.golang.org/grpc/codes"
|
|
healthpb "google.golang.org/grpc/health/grpc_health_v1"
|
|
"google.golang.org/grpc/internal"
|
|
"google.golang.org/grpc/internal/backoff"
|
|
"google.golang.org/grpc/status"
|
|
)
|
|
|
|
const maxDelay = 120 * time.Second
|
|
|
|
var backoffStrategy = backoff.Exponential{MaxDelay: maxDelay}
|
|
var backoffFunc = func(ctx context.Context, retries int) bool {
|
|
d := backoffStrategy.Backoff(retries)
|
|
timer := time.NewTimer(d)
|
|
select {
|
|
case <-timer.C:
|
|
return true
|
|
case <-ctx.Done():
|
|
timer.Stop()
|
|
return false
|
|
}
|
|
}
|
|
|
|
func init() {
|
|
internal.HealthCheckFunc = clientHealthCheck
|
|
}
|
|
|
|
func clientHealthCheck(ctx context.Context, newStream func() (interface{}, error), reportHealth func(bool), service string) error {
|
|
tryCnt := 0
|
|
|
|
retryConnection:
|
|
for {
|
|
// Backs off if the connection has failed in some way without receiving a message in the previous retry.
|
|
if tryCnt > 0 && !backoffFunc(ctx, tryCnt-1) {
|
|
return nil
|
|
}
|
|
tryCnt++
|
|
|
|
if ctx.Err() != nil {
|
|
return nil
|
|
}
|
|
rawS, err := newStream()
|
|
if err != nil {
|
|
continue retryConnection
|
|
}
|
|
|
|
s, ok := rawS.(grpc.ClientStream)
|
|
// Ideally, this should never happen. But if it happens, the server is marked as healthy for LBing purposes.
|
|
if !ok {
|
|
reportHealth(true)
|
|
return fmt.Errorf("newStream returned %v (type %T); want grpc.ClientStream", rawS, rawS)
|
|
}
|
|
|
|
if err = s.SendMsg(&healthpb.HealthCheckRequest{Service: service}); err != nil && err != io.EOF {
|
|
// Stream should have been closed, so we can safely continue to create a new stream.
|
|
continue retryConnection
|
|
}
|
|
s.CloseSend()
|
|
|
|
resp := new(healthpb.HealthCheckResponse)
|
|
for {
|
|
err = s.RecvMsg(resp)
|
|
|
|
// Reports healthy for the LBing purposes if health check is not implemented in the server.
|
|
if status.Code(err) == codes.Unimplemented {
|
|
reportHealth(true)
|
|
return err
|
|
}
|
|
|
|
// Reports unhealthy if server's Watch method gives an error other than UNIMPLEMENTED.
|
|
if err != nil {
|
|
reportHealth(false)
|
|
continue retryConnection
|
|
}
|
|
|
|
// As a message has been received, removes the need for backoff for the next retry by reseting the try count.
|
|
tryCnt = 0
|
|
reportHealth(resp.Status == healthpb.HealthCheckResponse_SERVING)
|
|
}
|
|
}
|
|
}
|