use listen to ensure the port is free (#6990)

kubernetes · Jul 17, 2021 · f152efe · f152efe
1 parent bfc5a8a
commit f152efe
Showing 1 changed file with 4 additions and 4 deletions.
diff --git a/internal/net/net.go b/internal/net/net.go
@@ -29,12 +29,12 @@ func IsIPV6(ip _net.IP) bool {
 
 // IsPortAvailable checks if a TCP port is available or not
 func IsPortAvailable(p int) bool {
-	conn, err := _net.Dial("tcp", fmt.Sprintf(":%v", p))
+	ln, err := _net.Listen("tcp", fmt.Sprintf(":%v", p))
 	if err != nil {
-		return true
+		return false
 	}
-	defer conn.Close()
-	return false
+	defer ln.Close()
+	return true
 }
 
 // IsIPv6Enabled checks if IPV6 is enabled or not and we have