server: remove reaper, let runc take care of reaping

Signed-off-by: Antonio Murdaca <runcom@redhat.com>

oci/oci.go

@@ -17,8 +17,8 @@ import (
 	specs "github.com/opencontainers/runtime-spec/specs-go"
 
 	"github.com/Sirupsen/logrus"
-	"github.com/kubernetes-incubator/cri-o/utils"
 	"github.com/containernetworking/cni/pkg/ns"
+	"github.com/kubernetes-incubator/cri-o/utils"
 	"golang.org/x/sys/unix"
 	"k8s.io/kubernetes/pkg/fields"
 	pb "k8s.io/kubernetes/pkg/kubelet/api/v1alpha1/runtime"
@@ -275,6 +275,7 @@ func (r *Runtime) StopContainer(c *Container) error {
 			if err != nil && err != syscall.ESRCH {
 				return fmt.Errorf("failed to kill process: %v", err)
 			}
+			break
 		}
 		// Check if the process is still around
 		err := unix.Kill(c.state.Pid, 0)

server/server.go

@@ -15,7 +15,6 @@ import (
 	"github.com/kubernetes-incubator/cri-o/oci"
 	"github.com/kubernetes-incubator/cri-o/server/apparmor"
 	"github.com/kubernetes-incubator/cri-o/server/seccomp"
-	"github.com/kubernetes-incubator/cri-o/utils"
 	"github.com/opencontainers/runc/libcontainer/label"
 	rspec "github.com/opencontainers/runtime-spec/specs-go"
 	"github.com/rajatchopra/ocicni"
@@ -297,14 +296,6 @@ func seccompEnabled() bool {
 
 // New creates a new Server with options provided
 func New(config *Config) (*Server, error) {
-	// TODO: This will go away later when we have wrapper process or systemd acting as
-	// subreaper.
-	if err := utils.SetSubreaper(1); err != nil {
-		return nil, fmt.Errorf("failed to set server as subreaper: %v", err)
-	}
-
-	utils.StartReaper()
-
 	if err := os.MkdirAll(config.ImageDir, 0755); err != nil {
 		return nil, err
 	}

utils/utils.go

@@ -6,7 +6,6 @@ import (
 	"io"
 	"os"
 	"os/exec"
-	"os/signal"
 	"path/filepath"
 	"strings"
 	"syscall"
@@ -14,9 +13,6 @@ import (
 	"github.com/Sirupsen/logrus"
 )
 
-// PRSetChildSubreaper is the value of PR_SET_CHILD_SUBREAPER in prctl(2)
-const PRSetChildSubreaper = 36
-
 // ExecCmd executes a command with args and returns its output as a string along
 // with an error, if any
 func ExecCmd(name string, args ...string) (string, error) {
@@ -49,11 +45,6 @@ func ExecCmdWithStdStreams(stdin io.Reader, stdout, stderr io.Writer, name strin
 	return nil
 }
 
-// SetSubreaper sets the value i as the subreaper setting for the calling process
-func SetSubreaper(i int) error {
-	return Prctl(PRSetChildSubreaper, uintptr(i), 0, 0, 0)
-}
-
 // Prctl is a way to make the prctl linux syscall
 func Prctl(option int, arg2, arg3, arg4, arg5 uintptr) (err error) {
 	_, _, e1 := syscall.Syscall6(syscall.SYS_PRCTL, uintptr(option), arg2, arg3, arg4, arg5, 0)
@@ -135,40 +126,6 @@ func dockerRemove(container string) error {
 	return err
 }
 
-// StartReaper starts a goroutine to reap processes
-func StartReaper() {
-	logrus.Infof("Starting reaper")
-	go func() {
-		sigs := make(chan os.Signal, 10)
-		signal.Notify(sigs, syscall.SIGCHLD)
-		for {
-			// Wait for a child to terminate
-			sig := <-sigs
-			for {
-				// Reap processes
-				var status syscall.WaitStatus
-				cpid, err := syscall.Wait4(-1, &status, syscall.WNOHANG, nil)
-				if err != nil {
-					if err != syscall.ECHILD {
-						logrus.Debugf("wait4 after %v: %v", sig, err)
-					}
-					break
-				}
-				if cpid < 1 {
-					break
-				}
-				if status.Exited() {
-					logrus.Debugf("Reaped process with pid %d, exited with status %d", cpid, status.ExitStatus())
-				} else if status.Signaled() {
-					logrus.Debugf("Reaped process with pid %d, exited on %s", cpid, status.Signal())
-				} else {
-					logrus.Debugf("Reaped process with pid %d", cpid)
-				}
-			}
-		}
-	}()
-}
-
 // StatusToExitCode converts wait status code to an exit code
 func StatusToExitCode(status int) int {
 	return ((status) & 0xff00) >> 8