ss: support concurrent execution

When using goroutines, the behavior of CreateComDetailsFromNode resulted
in the deletion of the debug namespace, causing failure.

Here, we relocate the creation and deletion of the debug namespace
outside of the function to support running this function in parallel threads.

cmd/main.go

@@ -9,12 +9,15 @@ import (
 	"path/filepath"
 	"sync"
 
+	"golang.org/x/sync/errgroup"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+
 	clientutil "github.com/openshift-kni/commatrix/client"
 	"github.com/openshift-kni/commatrix/commatrix"
+	"github.com/openshift-kni/commatrix/consts"
+	"github.com/openshift-kni/commatrix/debug"
 	"github.com/openshift-kni/commatrix/ss"
 	"github.com/openshift-kni/commatrix/types"
-	"golang.org/x/sync/errgroup"
-	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 )
 
 func main() {
@@ -110,12 +113,37 @@ func main() {
 	}
 
 	nodesComDetails := []types.ComDetails{}
+
+	err = debug.CreateNamespace(cs, consts.DefaultDebugNamespace)
+	if err != nil {
+		panic(err)
+	}
+	defer func() {
+		err := debug.DeleteNamespace(cs, consts.DefaultDebugNamespace)
+		if err != nil {
+			panic(err)
+		}
+	}()
+
 	nLock := &sync.Mutex{}
 	g := new(errgroup.Group)
 	for _, n := range nodesList.Items {
 		node := n
 		g.Go(func() error {
-			cds, err := ss.CreateComDetailsFromNode(cs, &node, tcpFile, udpFile)
+			nLock.Lock()
+			debugPod, err := debug.New(cs, node.Name, consts.DefaultDebugNamespace, consts.DefaultDebugPodImage)
+			if err != nil {
+				return err
+			}
+			nLock.Unlock()
+			defer func() {
+				err := debugPod.Clean()
+				if err != nil {
+					fmt.Printf("failed cleaning debug pod %s: %v", debugPod, err)
+				}
+			}()
+
+			cds, err := ss.CreateComDetailsFromNode(debugPod, &node, tcpFile, udpFile)
 			if err != nil {
 				return err
 			}

debug/debug.go

@@ -35,11 +35,6 @@ func New(cs *client.ClientSet, node string, namespace string, image string) (*De
 		return nil, errors.New("failed creating new debug pod: got empty namespace")
 	}
 
-	err := createNamespace(cs, namespace)
-	if err != nil {
-		return nil, err
-	}
-
 	pod, err := createPodAndWait(cs, interval, timeout, node, namespace, image)
 	if err != nil {
 		return nil, err
@@ -86,11 +81,6 @@ func (dp *DebugPod) Clean() error {
 		return fmt.Errorf("failed deleting debug pod %s/%s: %v\n%s", dp.Namespace, dp.Name, err, string(output))
 	}
 
-	output, err = exec.Command("oc", "delete", "ns", dp.Namespace).CombinedOutput()
-	if err != nil {
-		return fmt.Errorf("failed deleting debug namespace %s: %v\n%s", dp.Namespace, err, string(output))
-	}
-
 	return nil
 }
 
@@ -290,7 +280,7 @@ func getPodDefinition(node string, namespace string, image string) *corev1.Pod {
 	}
 }
 
-func createNamespace(cs *client.ClientSet, namespace string) error {
+func CreateNamespace(cs *client.ClientSet, namespace string) error {
 	ns := getNamespaceDefinition(namespace)
 	_, err := cs.Namespaces().Create(context.TODO(), ns, metav1.CreateOptions{})
 	if err != nil && !k8serrors.IsAlreadyExists(err) {
@@ -300,6 +290,15 @@ func createNamespace(cs *client.ClientSet, namespace string) error {
 	return nil
 }
 
+func DeleteNamespace(cs *client.ClientSet, namespace string) error {
+	err := cs.Namespaces().Delete(context.TODO(), namespace, metav1.DeleteOptions{})
+	if err != nil {
+		return fmt.Errorf("failed deleting namespace %s: %v", namespace, err)
+	}
+
+	return nil
+}
+
 func getNamespaceDefinition(namespace string) *corev1.Namespace {
 	return &corev1.Namespace{
 		ObjectMeta: metav1.ObjectMeta{

ss/ss.go

@@ -11,7 +11,6 @@ import (
 	log "github.com/sirupsen/logrus"
 	corev1 "k8s.io/api/core/v1"
 
-	"github.com/openshift-kni/commatrix/client"
 	"github.com/openshift-kni/commatrix/consts"
 	"github.com/openshift-kni/commatrix/debug"
 	"github.com/openshift-kni/commatrix/nodes"
@@ -24,18 +23,7 @@ const (
 	duration              = time.Second * 5
 )
 
-func CreateComDetailsFromNode(cs *client.ClientSet, node *corev1.Node, tcpFile, udpFile *os.File) ([]types.ComDetails, error) {
-	debugPod, err := debug.New(cs, node.Name, consts.DefaultDebugNamespace, consts.DefaultDebugPodImage)
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		err := debugPod.Clean()
-		if err != nil {
-			fmt.Printf("failed cleaning debug pod %s: %v", debugPod, err)
-		}
-	}()
-
+func CreateComDetailsFromNode(debugPod *debug.DebugPod, node *corev1.Node, tcpFile, udpFile *os.File) ([]types.ComDetails, error) {
 	ssOutTCP, err := debugPod.ExecWithRetry("ss -anpltH", interval, duration)
 	if err != nil {
 		return nil, err