Implementation overview: https://gist.github.com/klauspost/1801c858d5e0df391114436fdad6987b
74 lines
2.3 KiB
Go
74 lines
2.3 KiB
Go
/*
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* MinIO Cloud Storage, (C) 2016 MinIO, Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package cmd
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import (
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"context"
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"os"
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"os/exec"
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"syscall"
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)
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// Type of service signals currently supported.
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type serviceSignal int
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const (
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serviceRestart serviceSignal = iota // Restarts the server.
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serviceStop // Stops the server.
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// Add new service requests here.
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)
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// Global service signal channel.
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var globalServiceSignalCh chan serviceSignal
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// GlobalServiceDoneCh - Global service done channel.
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var GlobalServiceDoneCh <-chan struct{}
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// GlobalContext context that is canceled when server is requested to shut down.
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var GlobalContext context.Context
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// cancelGlobalContext can be used to indicate server shutdown.
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var cancelGlobalContext context.CancelFunc
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// Initialize service mutex once.
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func init() {
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initGlobalContext()
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}
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func initGlobalContext() {
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GlobalContext, cancelGlobalContext = context.WithCancel(context.Background())
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GlobalServiceDoneCh = GlobalContext.Done()
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globalServiceSignalCh = make(chan serviceSignal)
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}
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// restartProcess starts a new process passing it the active fd's. It
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// doesn't fork, but starts a new process using the same environment and
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// arguments as when it was originally started. This allows for a newly
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// deployed binary to be started. It returns the pid of the newly started
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// process when successful.
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func restartProcess() error {
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// Use the original binary location. This works with symlinks such that if
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// the file it points to has been changed we will use the updated symlink.
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argv0, err := exec.LookPath(os.Args[0])
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if err != nil {
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return err
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}
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// Invokes the execve system call.
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// Re-uses the same pid. This preserves the pid over multiple server-respawns.
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return syscall.Exec(argv0, os.Args, os.Environ())
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}
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