move reaper from origin to here as it was deleted in source repository

main.go

@@ -13,13 +13,13 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/openshift/origin/pkg/util/proc"
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"k8s.io/klog/v2"
 
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 
+	"github.com/openshift/openshift-state-metrics/pkg/proc"
 	"github.com/openshift/openshift-state-metrics/pkg/version"
 	kcollectors "k8s.io/kube-state-metrics/pkg/collector"
 	koptions "k8s.io/kube-state-metrics/pkg/options"

pkg/proc/reaper.go

@@ -0,0 +1,37 @@
+// +build linux
+
+package proc
+
+import (
+	"os"
+	"os/signal"
+	"syscall"
+
+	"k8s.io/klog/v2"
+)
+
+// StartReaper starts a goroutine to reap processes if called from a process
+// that has pid 1.
+func StartReaper() {
+	if os.Getpid() == 1 {
+		klog.V(4).Infof("Launching reaper")
+		go func() {
+			sigs := make(chan os.Signal, 1)
+			signal.Notify(sigs, syscall.SIGCHLD)
+			for {
+				// Wait for a child to terminate
+				sig := <-sigs
+				klog.V(4).Infof("Signal received: %v", sig)
+				for {
+					// Reap processes
+					cpid, _ := syscall.Wait4(-1, nil, syscall.WNOHANG, nil)
+					if cpid < 1 {
+						break
+					}
+
+					klog.V(4).Infof("Reaped process with pid %d", cpid)
+				}
+			}
+		}()
+	}
+}

pkg/proc/reaper_unsupported.go

@@ -0,0 +1,8 @@
+// +build !linux
+
+package proc
+
+// StartReaper has no effect on non-linux platforms.
+// Support for other unices will be added.
+func StartReaper() {
+}