main: daemonize more thoroughly

As described at http://software.clapper.org/daemonize/ ,
a daemon should chdir to / and close its FDs.
This commit is contained in:
Jakob Unterwurzacher 2016-10-07 22:44:28 +02:00
parent 53257f4ee5
commit 14fd5ce598
1 changed files with 20 additions and 10 deletions

30
main.go
View File

@ -271,20 +271,30 @@ func main() {
tlog.Debug.Printf("cli args: %v", args)
srv := initFuseFrontend(masterkey, args, confFile)
tlog.Info.Println(tlog.ColorGreen + "Filesystem mounted and ready." + tlog.ColorReset)
// We are ready - send USR1 signal to our parent
// We have been forked into the background, as evidenced by the set
// "notifypid".
if args.notifypid > 0 {
// Chdir to the root directory so we don't block unmounting the CWD
os.Chdir("/")
// Switch to syslog
if !args.nosyslog {
tlog.Info.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_INFO)
tlog.Debug.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_DEBUG)
tlog.Warn.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
tlog.SwitchLoggerToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
// Daemons should close all fds (and we don't want to get killed by
// SIGPIPE if any of those get closed on the other end)
os.Stderr.Close()
os.Stdout.Close()
os.Stdin.Close()
}
// Send SIGUSR1 to our parent
sendUsr1(args.notifypid)
}
// If we have been forked into the background, as evidenced by the set
// "notifypid", switch to syslog. Unless "nosyslog" is set.
if args.notifypid > 0 && !args.nosyslog {
tlog.Info.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_INFO)
tlog.Debug.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_DEBUG)
tlog.Warn.SwitchToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
tlog.SwitchLoggerToSyslog(syslog.LOG_USER | syslog.LOG_WARNING)
}
// Wait for SIGINT in the background and unmount ourselves if we get it.
// This prevents a dangling "Transport endpoint is not connected" mountpoint.
// This prevents a dangling "Transport endpoint is not connected"
// mountpoint if the user hits CTRL-C.
handleSigint(srv, args.mountpoint)
// Jump into server loop. Returns when it gets an umount request from the kernel.
srv.Serve()