Add test for network failover

Signed-off-by: a.y.volkov <a.y.volkov@yadro.com>

pytest_tests/helpers/iptables_helper.py

@@ -0,0 +1,16 @@
+from ssh_helper import HostClient
+
+
+class IpTablesHelper:
+
+    @staticmethod
+    def drop_input_traffic_to_port(client: HostClient, ports: list[str]):
+        for port in ports:
+            cmd_output = client.exec(cmd=f'iptables -A INPUT -p tcp --dport {port} -j DROP')
+            assert cmd_output.rc == 0
+
+    @staticmethod
+    def restore_input_traffic_to_port(client: HostClient, ports: list[str]):
+        for port in ports:
+            cmd_output = client.exec(cmd=f'iptables -D INPUT -p tcp --dport {port} -j DROP')
+            assert cmd_output.rc == 0