text: import pytest
  from helpers.cluster import ClickHouseCluster
  
  cluster = ClickHouseCluster(__file__)
  instance = cluster.add_instance('instance')
  
  
  @pytest.fixture(scope="module", autouse=True)
  def setup_nodes():
      try:
          cluster.start()
          yield cluster
  
      finally:
          cluster.shutdown()
  
  
  def test_http_get_is_readonly():
      assert "Cannot execute query in readonly mode" in instance.http_query_and_get_error(
          "CREATE TABLE xxx (a Date) ENGINE = MergeTree(a, a, 256)")
      assert "Cannot modify 'readonly' setting in readonly mode" in instance.http_query_and_get_error(
          "CREATE TABLE xxx (a Date) ENGINE = MergeTree(a, a, 256)", params={"readonly": 0})
  