add cross cluster IT

Signed-off-by: Jialiang Liang <jiallian@amazon.com>

Author: RyanL1997

integ-test/src/test/java/org/opensearch/sql/security/CalciteCrossClusterSearchIT.java

@@ -8,8 +8,10 @@
 import static org.opensearch.sql.legacy.TestsConstants.TEST_INDEX_BANK;
 import static org.opensearch.sql.legacy.TestsConstants.TEST_INDEX_DOG;
 import static org.opensearch.sql.util.MatcherUtils.columnName;
+import static org.opensearch.sql.util.MatcherUtils.rows;
 import static org.opensearch.sql.util.MatcherUtils.schema;
 import static org.opensearch.sql.util.MatcherUtils.verifyColumn;
+import static org.opensearch.sql.util.MatcherUtils.verifyDataRows;
 import static org.opensearch.sql.util.MatcherUtils.verifySchema;
 
 import java.io.IOException;
@@ -146,4 +148,31 @@ public void testCrossClusterFieldsAndTableEquivalence() throws IOException {
     verifySchema(fieldsResult, schema("dog_name", "string"), schema("age", "bigint"));
     verifySchema(tableResult, schema("dog_name", "string"), schema("age", "bigint"));
   }
+
+  @Test
+  public void testCrossClusterRegexBasic() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "search source=%s | regex firstname='.*att.*' | fields firstname",
+                TEST_INDEX_BANK_REMOTE));
+    verifyDataRows(result, rows("Hattie"));
+  }
+
+  @Test
+  public void testCrossClusterRegexWithNegation() throws IOException {
+    JSONObject result =
+        executeQuery(
+            String.format(
+                "search source=%s | regex firstname!='.*att.*' | fields firstname",
+                TEST_INDEX_BANK_REMOTE));
+    verifyDataRows(
+        result,
+        rows("Virginia"),
+        rows("Elinor"),
+        rows("Dillard"),
+        rows("Dale"),
+        rows("Amber JOHnny"),
+        rows("Nanette"));
+  }
 }