MB-58691: Overwrite passed cluster with result from testset

This allow us to change the cluster variable of a testset and have the
modification manifest for the testrunner to correctly tear down the
correct cluster. This will be used in a future change to test node
remapping which tears down and recreates the original cluster at the
start and end of the test respectively.

Change-Id: I1ce5b15f03ff3ad9542fb76db4ed57705de97480
Reviewed-on: https://review.couchbase.org/c/ns_server/+/209394
Well-Formed: Build Bot <build@couchbase.com>
Well-Formed: Restriction Checker
Tested-by: Ben Huddleston <ben.huddleston@couchbase.com>
Reviewed-by: Peter Searby <peter.searby@couchbase.com>

cluster_tests/run.py

@@ -326,7 +326,8 @@ def main():
                                                       start_index)
         testset_start_ts = time.time_ns()
         # Run the testsets on the cluster
-        tests_executed, testset_errors, testset_not_ran, log_collection_time = \
+        tests_executed, testset_errors, testset_not_ran, log_collection_time,\
+            cluster = \
             run_testsets(cluster, testsets, total_num,
                          seed=seed,
                          stop_after_first_error=stop_after_first_error,
@@ -611,6 +612,7 @@ def skip_this_testset(error):
             executed += res[0]
             testset_errors = res[1]
             not_ran += res[2]
+            cluster = res[3]
         # We use a catch-all here because if we hit any errors while running
         # a testset, but not in a test, then it is likely an issue with the
         # cluster, so we should keep running more tests
@@ -668,7 +670,7 @@ def skip_this_testset(error):
                 print(f"Collected logs for {node.url}: {path}")
 
         log_collection_time += (time.time_ns() - collect_start_time)
-    return executed, errors, not_ran, log_collection_time
+    return executed, errors, not_ran, log_collection_time, cluster
 
 
 if __name__ == '__main__':

cluster_tests/testlib/testlib.py

@@ -123,6 +123,9 @@ def run_testset(testset, cluster, total_testsets_num, seed=None,
             _, err = safe_test_function_call(testset_instance, test,
                                              [], testiter, verbose=True,
                                              seed=test_seed)
+
+            cluster = testset_instance.cluster
+
             if err is not None:
                 errors.append(err)
 
@@ -154,7 +157,7 @@ def run_testset(testset, cluster, total_testsets_num, seed=None,
         if err is not None:
             errors.append(err)
 
-    return executed, errors, not_ran
+    return executed, errors, not_ran, cluster
 
 
 def test_name(testset, testname, testiter):