#2064: add handling of offline service to dns, ftp and database

tests/integration_tests/system/test_dns_client_server.py

@@ -1,3 +1,4 @@
+from primaite.simulator.network.hardware.node_operating_state import NodeOperatingState
 from primaite.simulator.network.hardware.nodes.computer import Computer
 from primaite.simulator.network.hardware.nodes.server import Server
 from primaite.simulator.system.services.dns.dns_client import DNSClient
@@ -24,3 +25,39 @@ def test_dns_client_server(uc2_network):
     # arcd.com is registered in dns server and should be saved to cache
     assert dns_client.check_domain_exists(target_domain="arcd.com")
     assert dns_client.dns_cache.get("arcd.com", None) is not None
+
+    assert len(dns_client.dns_cache) == 1
+
+
+def test_dns_client_requests_offline_dns_server(uc2_network):
+    client_1: Computer = uc2_network.get_node_by_hostname("client_1")
+    domain_controller: Server = uc2_network.get_node_by_hostname("domain_controller")
+
+    dns_client: DNSClient = client_1.software_manager.software["DNSClient"]
+    dns_server: DNSServer = domain_controller.software_manager.software["DNSServer"]
+
+    assert dns_client.operating_state == ServiceOperatingState.RUNNING
+    assert dns_server.operating_state == ServiceOperatingState.RUNNING
+
+    dns_server.show()
+
+    # arcd.com is registered in dns server
+    assert dns_client.check_domain_exists(target_domain="arcd.com")
+    assert dns_client.dns_cache.get("arcd.com", None) is not None
+
+    assert len(dns_client.dns_cache) == 1
+    dns_client.dns_cache = {}
+
+    domain_controller.power_off()
+
+    for i in range(domain_controller.shut_down_duration + 1):
+        uc2_network.apply_timestep(timestep=i)
+
+    assert domain_controller.operating_state == NodeOperatingState.OFF
+    assert dns_server.operating_state == ServiceOperatingState.STOPPED
+
+    # this time it should not cache because dns server is not online
+    assert dns_client.check_domain_exists(target_domain="arcd.com") is False
+    assert dns_client.dns_cache.get("arcd.com", None) is None
+
+    assert len(dns_client.dns_cache) == 0