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
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
|
// Copyright 2015 Light Code Labs, LLC
//
// 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 (
"log"
"os"
"os/signal"
"sync"
"github.com/mholt/caddy/telemetry"
"github.com/mholt/certmagic"
)
// TrapSignals create signal handlers for all applicable signals for this
// system. If your Go program uses signals, this is a rather invasive
// function; best to implement them yourself in that case. Signals are not
// required for the caddy package to function properly, but this is a
// convenient way to allow the user to control this part of your program.
func TrapSignals() {
trapSignalsCrossPlatform()
trapSignalsPosix()
}
// trapSignalsCrossPlatform captures SIGINT, which triggers forceful
// shutdown that executes shutdown callbacks first. A second interrupt
// signal will 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.Println("[INFO] SIGINT: Force quit")
for _, f := range OnProcessExit {
f() // important cleanup actions only
}
certmagic.CleanUpOwnLocks()
os.Exit(2)
}
log.Println("[INFO] SIGINT: Shutting down")
telemetry.AppendUnique("sigtrap", "SIGINT")
go telemetry.StopEmitting() // not guaranteed to finish in time; that's OK (just don't block!)
// important cleanup actions before shutdown callbacks
for _, f := range OnProcessExit {
f()
}
go func() {
certmagic.CleanUpOwnLocks()
os.Exit(executeShutdownCallbacks("SIGINT"))
}()
}
}()
}
// executeShutdownCallbacks executes the shutdown callbacks as initiated
// by signame. It logs any errors and returns the recommended exit status.
// This function is idempotent; subsequent invocations always return 0.
func executeShutdownCallbacks(signame string) (exitCode int) {
shutdownCallbacksOnce.Do(func() {
// execute third-party shutdown hooks
EmitEvent(ShutdownEvent, signame)
errs := allShutdownCallbacks()
if len(errs) > 0 {
for _, err := range errs {
log.Printf("[ERROR] %s shutdown: %v", signame, err)
}
exitCode = 4
}
})
return
}
// allShutdownCallbacks executes all the shutdown callbacks
// for all the instances, and returns all the errors generated
// during their execution. An error executing one shutdown
// callback does not stop execution of others. Only one shutdown
// callback is executed at a time.
func allShutdownCallbacks() []error {
var errs []error
instancesMu.Lock()
for _, inst := range instances {
errs = append(errs, inst.ShutdownCallbacks()...)
}
instancesMu.Unlock()
return errs
}
// shutdownCallbacksOnce ensures that shutdown callbacks
// for all instances are only executed once.
var shutdownCallbacksOnce sync.Once
|
