tests: create every cluster with its own ip prefix

Sometimes test can fail to cleanup ccm cluster which will lead to
failure of next tests if their IP addresses clashes.
To avoid that let's spin every cluster on it's own prefix.

Author: dkropachev

test-infra/src/main/java/com/datastax/oss/driver/api/testinfra/ccm/CcmBridge.java

@@ -48,6 +48,7 @@
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicBoolean;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.Collectors;
 import org.apache.commons.exec.CommandLine;
 import org.apache.commons.exec.DefaultExecutor;
@@ -62,6 +63,7 @@
 public class CcmBridge implements AutoCloseable {
 
   private static final Logger LOG = LoggerFactory.getLogger(CcmBridge.class);
+  private static final AtomicInteger CLUSTER_ID = new AtomicInteger();
 
   public static BackendType DISTRIBUTION =
       BackendType.valueOf(
@@ -209,7 +211,14 @@ private CcmBridge(
     } else {
       this.nodes = nodes;
     }
-    this.ipPrefix = ipPrefix;
+
+    if (ipPrefix == null || ipPrefix.isEmpty()) {
+      Integer clusterId = CLUSTER_ID.addAndGet(1);
+      this.ipPrefix = String.format("127.%d.%d.", clusterId / 255, (clusterId % 255) + 1);
+    } else {
+      this.ipPrefix = ipPrefix;
+    }
+
     this.cassandraConfiguration = cassandraConfiguration;
     this.dseConfiguration = dseConfiguration;
     this.rawDseYaml = dseConfigurationRawYaml;
@@ -665,7 +674,7 @@ public static class Builder {
     private final Map<String, Object> dseConfiguration = new LinkedHashMap<>();
     private final List<String> dseRawYaml = new ArrayList<>();
     private final List<String> jvmArgs = new ArrayList<>();
-    private String ipPrefix = "127.0.0.";
+    private String ipPrefix;
     private final List<String> createOptions = new ArrayList<>();
     private final List<String> dseWorkloads = new ArrayList<>();