28f561297c
Add handler for SIGUSR1 based on feedback regarding when to dump goroutine stacks. This will also dump goroutine stack traces on SIGQUIT followed by a hard-exit from the daemon. Docker-DCO-1.1-Signed-off-by: Phil Estes <estesp@linux.vnet.ibm.com> (github: estesp)
64 lines
2.1 KiB
Go
64 lines
2.1 KiB
Go
package signal
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import (
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"os"
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gosignal "os/signal"
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"runtime"
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"sync/atomic"
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"syscall"
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"github.com/Sirupsen/logrus"
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)
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// Trap sets up a simplified signal "trap", appropriate for common
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// behavior expected from a vanilla unix command-line tool in general
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// (and the Docker engine in particular).
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//
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// * If SIGINT or SIGTERM are received, `cleanup` is called, then the process is terminated.
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// * If SIGINT or SIGTERM are received 3 times before cleanup is complete, then cleanup is
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// skipped and the process is terminated immediately (allows force quit of stuck daemon)
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// * A SIGQUIT always causes an exit without cleanup, with a goroutine dump preceding exit.
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//
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func Trap(cleanup func()) {
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c := make(chan os.Signal, 1)
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// we will handle INT, TERM, QUIT here
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signals := []os.Signal{os.Interrupt, syscall.SIGTERM, syscall.SIGQUIT}
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gosignal.Notify(c, signals...)
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go func() {
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interruptCount := uint32(0)
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for sig := range c {
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go func(sig os.Signal) {
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logrus.Infof("Processing signal '%v'", sig)
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switch sig {
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case os.Interrupt, syscall.SIGTERM:
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if atomic.LoadUint32(&interruptCount) < 3 {
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// Initiate the cleanup only once
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if atomic.AddUint32(&interruptCount, 1) == 1 {
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// Call the provided cleanup handler
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cleanup()
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os.Exit(0)
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} else {
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return
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}
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} else {
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// 3 SIGTERM/INT signals received; force exit without cleanup
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logrus.Infof("Forcing docker daemon shutdown without cleanup; 3 interrupts received")
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}
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case syscall.SIGQUIT:
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DumpStacks()
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logrus.Infof("Forcing docker daemon shutdown without cleanup on SIGQUIT")
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}
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//for the SIGINT/TERM, and SIGQUIT non-clean shutdown case, exit with 128 + signal #
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os.Exit(128 + int(sig.(syscall.Signal)))
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}(sig)
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}
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}()
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}
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func DumpStacks() {
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buf := make([]byte, 16384)
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buf = buf[:runtime.Stack(buf, true)]
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// Note that if the daemon is started with a less-verbose log-level than "info" (the default), the goroutine
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// traces won't show up in the log.
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logrus.Infof("=== BEGIN goroutine stack dump ===\n%s\n=== END goroutine stack dump ===", buf)
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}
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