fix: fix RandomName's dash when no prefix provided

pkg/envconf/config.go

@@ -17,11 +17,10 @@ limitations under the License.
 package envconf
 
 import (
+	"crypto/rand"
 	"encoding/hex"
 	"fmt"
-	"math/rand"
 	"regexp"
-	"time"
 
 	log "k8s.io/klog/v2"
 
@@ -300,8 +299,10 @@ func RandomName(prefix string, n int) string {
 	if len(prefix) >= n {
 		return prefix
 	}
-	rand.Seed(time.Now().UnixNano())
 	p := make([]byte, n)
 	rand.Read(p)
+	if len(prefix) == 0 {
+		return hex.EncodeToString(p)[:n]
+	}
 	return fmt.Sprintf("%s-%s", prefix, hex.EncodeToString(p))[:n]
 }

pkg/envconf/config_test.go

@@ -18,7 +18,9 @@ package envconf
 
 import (
 	"flag"
+	"math/rand"
 	"os"
+	"strings"
 	"testing"
 )
 
@@ -85,3 +87,21 @@ func TestConfig_New_WithIgnorePanicRecovery(t *testing.T) {
 		t.Error("expected ignore-panic-recovery mode to be enabled when -disable-graceful-teardown argument is passed")
 	}
 }
+
+func TestRandomName(t *testing.T) {
+	const maxLen = 64
+
+	t.Run("no prefix yields random name without dash", func(t *testing.T) {
+		out := RandomName("", int(rand.Int31n(maxLen)))
+		if strings.Contains(out, "-") {
+			t.Errorf("random name %q shouldn't contain a dash when no prefix provided", out)
+		}
+	})
+
+	t.Run("non empty prefix yields random name with dash", func(t *testing.T) {
+		out := RandomName("abc", int(rand.Int31n(maxLen)))
+		if !strings.Contains(out, "-") {
+			t.Errorf("random name %q should contain a dash when prefix provided", out)
+		}
+	})
+}