caddy/sigtrap.go

71 lines
2.0 KiB
Go

// Copyright 2015 Matthew Holt and The Caddy 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 caddy
import (
"context"
"os"
"os/signal"
"go.uber.org/zap"
)
// TrapSignals create signal/interrupt handlers as best it can for the
// current OS. This is a rather invasive function to call in a Go program
// that captures signals already, so in that case it would be better to
// implement these handlers yourself.
func TrapSignals() {
trapSignalsCrossPlatform()
trapSignalsPosix()
}
// trapSignalsCrossPlatform captures SIGINT or interrupt (depending
// on the OS), which initiates a graceful shutdown. A second SIGINT
// or interrupt will forcefully exit the process immediately.
func trapSignalsCrossPlatform() {
go func() {
shutdown := make(chan os.Signal, 1)
signal.Notify(shutdown, os.Interrupt)
for i := 0; true; i++ {
<-shutdown
if i > 0 {
Log().Warn("force quit", zap.String("signal", "SIGINT"))
os.Exit(ExitCodeForceQuit)
}
Log().Info("shutting down", zap.String("signal", "SIGINT"))
go exitProcessFromSignal("SIGINT")
}
}()
}
// exitProcessFromSignal exits the process from a system signal.
func exitProcessFromSignal(sigName string) {
logger := Log().With(zap.String("signal", sigName))
exitProcess(context.TODO(), logger)
}
// Exit codes. Generally, you should NOT
// automatically restart the process if the
// exit code is ExitCodeFailedStartup (1).
const (
ExitCodeSuccess = iota
ExitCodeFailedStartup
ExitCodeForceQuit
ExitCodeFailedQuit
)