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// 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 (
"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 gracefulStop("SIGINT")
}
}()
}
// gracefulStop exits the process as gracefully as possible.
// It always exits, even if there are errors shutting down.
func gracefulStop(sigName string) {
exitCode := ExitCodeSuccess
defer func() {
Log().Info("shutdown done", zap.String("signal", sigName))
os.Exit(exitCode)
}()
err := stopAndCleanup()
if err != nil {
Log().Error("stopping config",
zap.String("signal", sigName),
zap.Error(err))
exitCode = ExitCodeFailedQuit
}
if adminServer != nil {
err = stopAdminServer(adminServer)
if err != nil {
Log().Error("stopping admin endpoint",
zap.String("signal", sigName),
zap.Error(err))
exitCode = ExitCodeFailedQuit
}
}
}
// Exit codes. Generally, you should NOT
// automatically restart the process if the
// exit code is ExitCodeFailedStartup (1).
const (
ExitCodeSuccess = iota
ExitCodeFailedStartup
ExitCodeForceQuit
ExitCodeFailedQuit
)
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