blob: 62cbfaf1ca2b78a98fb11f05fd604161dad0f037 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
|
package trap // import "github.com/docker/docker/cmd/dockerd/trap"
import (
"fmt"
"os"
"os/signal"
"sync/atomic"
"syscall"
)
// Trap sets up a simplified signal "trap", appropriate for common
// behavior expected from a vanilla unix command-line tool in general
// (and the Docker engine in particular).
//
// - If SIGINT or SIGTERM are received, `cleanup` is called, then the process is terminated.
// - If SIGINT or SIGTERM are received 3 times before cleanup is complete, then cleanup is
// skipped and the process is terminated immediately (allows force quit of stuck daemon)
func Trap(cleanup func(), logger interface {
Info(args ...interface{})
}) {
c := make(chan os.Signal, 1)
// we will handle INT, TERM here
signal.Notify(c, os.Interrupt, syscall.SIGTERM)
go func() {
interruptCount := uint32(0)
for sig := range c {
go func(sig os.Signal) {
logger.Info(fmt.Sprintf("Processing signal '%v'", sig))
switch sig {
case os.Interrupt, syscall.SIGTERM:
if atomic.LoadUint32(&interruptCount) < 3 {
// Initiate the cleanup only once
if atomic.AddUint32(&interruptCount, 1) == 1 {
// Call the provided cleanup handler
cleanup()
os.Exit(0)
} else {
return
}
} else {
// 3 SIGTERM/INT signals received; force exit without cleanup
logger.Info("Forcing docker daemon shutdown without cleanup; 3 interrupts received")
}
}
// for the SIGINT/TERM non-clean shutdown case, exit with 128 + signal #
os.Exit(128 + int(sig.(syscall.Signal)))
}(sig)
}
}()
}
|
