Merge pull request #29380 from bboreham/kill-setpgid

Automatic merge from submit-queue

Fix killing child sudo process in e2e_node tests

Fixes #29211.

The context is we are trying to kill a process started as `sudo kube-apiserver`, but `sudo` ignores signals from the same process group. Applying `Setpgid` means the `sudo kill` process won't be in the same process group, so will not fall foul of this nifty feature.

I also took the liberty of removing some code setting `Pdeathsig` because it claims to be doing something  in the same area, but actually it doesn't do that at all.  The setting is applied to the forked process, i.e. `sudo`, and it means the `sudo` will get killed if we (`e2e_node.test`) die.  This (a) isn't what the comment says and (b) doesn't help because sending SIGKILL to the sudo process leaves sudo's child alive.

I didn't use the "hack for linux-only" approach because I think `Setpgid` is available on all platforms that `e2e_node` builds on.
This commit is contained in:
k8s-merge-robot 2016-07-27 03:18:15 -07:00 committed by GitHub
commit 03fe6b962c

View File

@ -26,7 +26,6 @@ import (
"os/exec"
"path"
"path/filepath"
"reflect"
"strconv"
"strings"
"syscall"
@ -295,18 +294,6 @@ func (es *e2eService) startServer(cmd *healthCheckCommand) error {
cmd.Cmd.Stdout = outfile
cmd.Cmd.Stderr = outfile
// Killing the sudo command should kill the server as well.
attrs := &syscall.SysProcAttr{}
// Hack to set linux-only field without build tags.
deathSigField := reflect.ValueOf(attrs).Elem().FieldByName("Pdeathsig")
if deathSigField.IsValid() {
deathSigField.Set(reflect.ValueOf(syscall.SIGKILL))
} else {
cmdErrorChan <- fmt.Errorf("Failed to set Pdeathsig field (non-linux build)")
return
}
cmd.Cmd.SysProcAttr = attrs
// Run the command
err = cmd.Run()
if err != nil {
@ -372,7 +359,10 @@ func (k *killCmd) Kill() error {
const timeout = 10 * time.Second
for _, signal := range []string{"-TERM", "-KILL"} {
glog.V(2).Infof("Killing process %d (%s) with %s", pid, name, signal)
_, err := exec.Command("sudo", "kill", signal, strconv.Itoa(pid)).Output()
cmd := exec.Command("sudo", "kill", signal, strconv.Itoa(pid))
// Run the 'kill' command in a separate process group so sudo doesn't ignore it
cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
_, err := cmd.Output()
if err != nil {
glog.Errorf("Error signaling process %d (%s) with %s: %v", pid, name, signal, err)
continue