Merged PR 439: #2641: Added a check for software health state in db service + tests

## Summary
Added a check in the database service process_sql method that checks if the Database Service is in a GOOD state (mainly so that the database service being in a fixed state returns an error)

## Test process
https://dev.azure.com/ma-dev-uk/PrimAITE/_git/PrimAITE/pullrequest/439?_a=files&path=/tests/integration_tests/system/test_database_on_node.py

https://dev.azure.com/ma-dev-uk/PrimAITE/_git/PrimAITE/pullrequest/439?_a=files&path=/tests/integration_tests/system/test_web_client_server_and_database.py

## Checklist
- [X] PR is linked to a **work item**
- [X] **acceptance criteria** of linked ticket are met
- [X] performed **self-review** of the code
- [X] written **tests** for any new functionality added with this PR
- [ ] updated the **documentation** if this PR changes or adds functionality
- [ ] written/updated **design docs** if this PR implements new functionality
- [ ] updated the **change log**
- [X] ran **pre-commit** checks for code style
- [ ] attended to any **TO-DOs** left in the code

#2641: Added a check for software health state in db service + tests

Related work items: #2641

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

@@ -197,7 +197,11 @@ class DatabaseService(Service):
             status_code = 503  # service unavailable
             if self.health_state_actual == SoftwareHealthState.OVERWHELMED:
                 self.sys_log.error(f"{self.name}: Connect request for {src_ip=} declined. Service is at capacity.")
-            if self.health_state_actual == SoftwareHealthState.GOOD:
+            if self.health_state_actual in [
+                SoftwareHealthState.GOOD,
+                SoftwareHealthState.FIXING,
+                SoftwareHealthState.COMPROMISED,
+            ]:
                 if self.password == password:
                     status_code = 200  # ok
                     connection_id = self._generate_connection_id()
@@ -244,6 +248,10 @@ class DatabaseService(Service):
             self.sys_log.error(f"{self.name}: Failed to run {query} because the database file is missing.")
             return {"status_code": 404, "type": "sql", "data": False}
 
+        if self.health_state_actual is not SoftwareHealthState.GOOD:
+            self.sys_log.error(f"{self.name}: Failed to run {query} because the database service is unavailable.")
+            return {"status_code": 500, "type": "sql", "data": False}
+
         if query == "SELECT":
             if self.db_file.health_status == FileSystemItemHealthStatus.CORRUPT:
                 return {

tests/integration_tests/system/test_database_on_node.py

@@ -14,6 +14,7 @@ from primaite.simulator.system.applications.database_client import DatabaseClien
 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
+from primaite.simulator.system.software import SoftwareHealthState
 
 
 @pytest.fixture(scope="function")
@@ -213,6 +214,110 @@ def test_restore_backup_after_deleting_file_without_updating_scan(uc2_network):
     assert db_service.db_file.visible_health_status == FileSystemItemHealthStatus.GOOD  # now looks good
 
 
+def test_database_service_fix(uc2_network):
+    """Test that the software fix applies to database service."""
+    db_server: Server = uc2_network.get_node_by_hostname("database_server")
+    db_service: DatabaseService = db_server.software_manager.software["DatabaseService"]
+
+    assert db_service.backup_database() is True
+
+    # delete database locally
+    db_service.file_system.delete_file(folder_name="database", file_name="database.db")
+
+    # db file is gone, reduced to atoms
+    assert db_service.db_file is None
+
+    db_service.fix()  # fix the database service
+
+    assert db_service.health_state_actual == SoftwareHealthState.FIXING
+
+    # apply timestep until the fix is applied
+    for i in range(db_service.fixing_duration + 1):
+        uc2_network.apply_timestep(i)
+
+    assert db_service.db_file.health_status == FileSystemItemHealthStatus.GOOD
+    assert db_service.health_state_actual == SoftwareHealthState.GOOD
+
+
+def test_database_cannot_be_queried_while_fixing(uc2_network):
+    """Tests that the database service cannot be queried if the service is being fixed."""
+    db_server: Server = uc2_network.get_node_by_hostname("database_server")
+    db_service: DatabaseService = db_server.software_manager.software["DatabaseService"]
+
+    web_server: Server = uc2_network.get_node_by_hostname("web_server")
+    db_client: DatabaseClient = web_server.software_manager.software["DatabaseClient"]
+
+    db_connection: DatabaseClientConnection = db_client.get_new_connection()
+
+    assert db_connection.query(sql="SELECT")
+
+    assert db_service.backup_database() is True
+
+    # delete database locally
+    db_service.file_system.delete_file(folder_name="database", file_name="database.db")
+
+    # db file is gone, reduced to atoms
+    assert db_service.db_file is None
+
+    db_service.fix()  # fix the database service
+    assert db_service.health_state_actual == SoftwareHealthState.FIXING
+
+    # fails to query because database is in FIXING state
+    assert db_connection.query(sql="SELECT") is False
+
+    # apply timestep until the fix is applied
+    for i in range(db_service.fixing_duration + 1):
+        uc2_network.apply_timestep(i)
+
+    assert db_service.health_state_actual == SoftwareHealthState.GOOD
+
+    assert db_service.db_file.health_status == FileSystemItemHealthStatus.GOOD
+
+    assert db_connection.query(sql="SELECT")
+
+
+def test_database_can_create_connection_while_fixing(uc2_network):
+    """Tests that connections cannot be created while the database is being fixed."""
+    db_server: Server = uc2_network.get_node_by_hostname("database_server")
+    db_service: DatabaseService = db_server.software_manager.software["DatabaseService"]
+
+    client_2: Server = uc2_network.get_node_by_hostname("client_2")
+    db_client: DatabaseClient = client_2.software_manager.software["DatabaseClient"]
+
+    db_connection: DatabaseClientConnection = db_client.get_new_connection()
+
+    assert db_connection.query(sql="SELECT")
+
+    assert db_service.backup_database() is True
+
+    # delete database locally
+    db_service.file_system.delete_file(folder_name="database", file_name="database.db")
+
+    # db file is gone, reduced to atoms
+    assert db_service.db_file is None
+
+    db_service.fix()  # fix the database service
+    assert db_service.health_state_actual == SoftwareHealthState.FIXING
+
+    # fails to query because database is in FIXING state
+    assert db_connection.query(sql="SELECT") is False
+
+    # should be able to create a new connection
+    new_db_connection: DatabaseClientConnection = db_client.get_new_connection()
+    assert new_db_connection is not None
+    assert new_db_connection.query(sql="SELECT") is False  # still should fail to query because FIXING
+
+    # apply timestep until the fix is applied
+    for i in range(db_service.fixing_duration + 1):
+        uc2_network.apply_timestep(i)
+
+    assert db_service.health_state_actual == SoftwareHealthState.GOOD
+    assert db_service.db_file.health_status == FileSystemItemHealthStatus.GOOD
+
+    assert db_connection.query(sql="SELECT")
+    assert new_db_connection.query(sql="SELECT")
+
+
 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")

tests/integration_tests/system/test_web_client_server_and_database.py

@@ -16,6 +16,7 @@ from primaite.simulator.system.services.database.database_service import Databas
 from primaite.simulator.system.services.dns.dns_client import DNSClient
 from primaite.simulator.system.services.dns.dns_server import DNSServer
 from primaite.simulator.system.services.web_server.web_server import WebServer
+from primaite.simulator.system.software import SoftwareHealthState
 
 
 @pytest.fixture(scope="function")
@@ -110,6 +111,29 @@ def test_web_client_requests_users(web_client_web_server_database):
     assert web_browser.get_webpage()
 
 
+def test_database_fix_disrupts_web_client(uc2_network):
+    """Tests that the database service being in fixed state disrupts the web client."""
+    computer: Computer = uc2_network.get_node_by_hostname("client_1")
+    db_server: Server = uc2_network.get_node_by_hostname("database_server")
+
+    web_browser: WebBrowser = computer.software_manager.software.get("WebBrowser")
+    database_service: DatabaseService = db_server.software_manager.software.get("DatabaseService")
+
+    # fix the database service
+    database_service.fix()
+
+    assert database_service.health_state_actual == SoftwareHealthState.FIXING
+
+    assert web_browser.get_webpage() is False
+
+    for i in range(database_service.fixing_duration + 1):
+        uc2_network.apply_timestep(i)
+
+    assert database_service.health_state_actual == SoftwareHealthState.GOOD
+
+    assert web_browser.get_webpage()
+
+
 class TestWebBrowserHistory:
     def test_populating_history(self, web_client_web_server_database):
         network, computer, _, _ = web_client_web_server_database