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

src/primaite/simulator/system/services/database/database_service.py

@@ -173,6 +173,9 @@ class DatabaseService(Service):
         :param session_id: The session identifier.
         :return: True if the Status Code is 200, otherwise False.
         """
+        if not super().receive(payload=payload, session_id=session_id, **kwargs):
+            return False
+
         result = {"status_code": 500, "data": []}
         if isinstance(payload, dict) and payload.get("type"):
             if payload["type"] == "connect_request":

src/primaite/simulator/system/services/dns/dns_server.py

@@ -88,10 +88,14 @@ class DNSServer(Service):
 
         :return: True if DNS request returns a valid IP, otherwise, False
         """
+        if not super().receive(payload=payload, session_id=session_id, **kwargs):
+            return False
+
         # The payload should be a DNS packet
         if not isinstance(payload, DNSPacket):
             _LOGGER.debug(f"{payload} is not a DNSPacket")
             return False
+
         # cast payload into a DNS packet
         payload: DNSPacket = payload
         if payload.dns_request is not None:

src/primaite/simulator/system/services/ftp/ftp_server.py

@@ -86,10 +86,10 @@ class FTPServer(FTPServiceABC):
         prevents an FTP request loop - FTP client and servers can exist on
         the same node.
         """
-        if payload.status_code is not None:
+        if not super().receive(payload=payload, session_id=session_id, **kwargs):
             return False
 
-        if not super().receive(payload=payload, session_id=session_id, **kwargs):
+        if payload.status_code is not None:
             return False
 
         self.send(self._process_ftp_command(payload=payload, session_id=session_id), session_id)

src/primaite/simulator/system/services/web_server/web_server.py

@@ -155,12 +155,12 @@ class WebServer(Service):
         :param: payload: The payload to send.
         :param: session_id: The id of the session. Optional.
         """
+        if not super().receive(payload=payload, session_id=session_id, **kwargs):
+            return False
+
         # check if the payload is an HTTPPacket
         if not isinstance(payload, HttpRequestPacket):
             self.sys_log.error("Payload is not an HTTPPacket")
             return False
 
-        if not super().receive(payload=payload, session_id=session_id, **kwargs):
-            return False
-
         return self._process_http_request(payload=payload, session_id=session_id)

src/primaite/simulator/system/software.py

@@ -3,7 +3,7 @@ from enum import Enum
 from ipaddress import IPv4Address
 from typing import Any, Dict, Optional
 
-from primaite.simulator.core import RequestManager, RequestType, SimComponent
+from primaite.simulator.core import _LOGGER, RequestManager, RequestType, SimComponent
 from primaite.simulator.file_system.file_system import FileSystem, Folder
 from primaite.simulator.network.hardware.node_operating_state import NodeOperatingState
 from primaite.simulator.network.transmission.transport_layer import Port
@@ -264,5 +264,6 @@ class IOSoftware(Software):
         """
         # return false if node that software is on is off
         if self.software_manager and self.software_manager.node.operating_state is NodeOperatingState.OFF:
+            _LOGGER.debug(f"{self.name} Error: {self.software_manager.node.hostname} is not online.")
             return False
         return True

tests/integration_tests/system/test_database_on_node.py

@@ -1,9 +1,11 @@
 from ipaddress import IPv4Address
 
+from primaite.simulator.network.hardware.node_operating_state import NodeOperatingState
 from primaite.simulator.network.hardware.nodes.server import Server
 from primaite.simulator.system.applications.database_client import DatabaseClient
 from primaite.simulator.system.services.database.database_service import DatabaseService
 from primaite.simulator.system.services.ftp.ftp_server import FTPServer
+from primaite.simulator.system.services.service import ServiceOperatingState
 
 
 def test_database_client_server_connection(uc2_network):
@@ -55,7 +57,8 @@ def test_database_client_query(uc2_network):
     """Tests DB query across the network returns HTTP status 200 and date."""
     web_server: Server = uc2_network.get_node_by_hostname("web_server")
     db_client: DatabaseClient = web_server.software_manager.software["DatabaseClient"]
-    db_client.connect()
+
+    assert db_client.connected
 
     assert db_client.query("SELECT")
 
@@ -92,3 +95,28 @@ def test_restore_backup(uc2_network):
     assert db_service.restore_backup() is True
 
     assert db_service.file_system.get_file(folder_name="database", file_name="database.db") is not None
+
+
+def test_database_client_cannot_query_offline_database_server(uc2_network):
+    """Tests DB query across the network returns HTTP status 404 when db server is offline."""
+    db_server: Server = uc2_network.get_node_by_hostname("database_server")
+    db_service: DatabaseService = db_server.software_manager.software["DatabaseService"]
+
+    assert db_server.operating_state is NodeOperatingState.ON
+    assert db_service.operating_state is ServiceOperatingState.RUNNING
+
+    web_server: Server = uc2_network.get_node_by_hostname("web_server")
+    db_client: DatabaseClient = web_server.software_manager.software["DatabaseClient"]
+    assert db_client.connected
+
+    assert db_client.query("SELECT") is True
+
+    db_server.power_off()
+
+    for i in range(db_server.shut_down_duration + 1):
+        uc2_network.apply_timestep(timestep=i)
+
+    assert db_server.operating_state is NodeOperatingState.OFF
+    assert db_service.operating_state is ServiceOperatingState.STOPPED
+
+    assert db_client.query("SELECT") is False

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

tests/unit_tests/_primaite/_simulator/_system/_services/test_dns.py

@@ -3,6 +3,7 @@ from ipaddress import IPv4Address
 import pytest
 
 from primaite.simulator.network.hardware.base import Node
+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.network.protocols.dns import DNSPacket, DNSReply, DNSRequest
@@ -15,10 +16,13 @@ from primaite.simulator.system.services.dns.dns_server import DNSServer
 @pytest.fixture(scope="function")
 def dns_server() -> Node:
     node = Server(
-        hostname="dns_server", ip_address="192.168.1.10", subnet_mask="255.255.255.0", default_gateway="192.168.1.1"
+        hostname="dns_server",
+        ip_address="192.168.1.10",
+        subnet_mask="255.255.255.0",
+        default_gateway="192.168.1.1",
+        operating_state=NodeOperatingState.ON,
     )
     node.software_manager.install(software_class=DNSServer)
-    node.software_manager.software["DNSServer"].start()
     return node