Island: Allow RepositoryErrors to be reraised

Previously, FileAgentLogRepository.get_agent_log() wrapped all errors as
RetrievalError, which is not necessarily correct. This commit allows all
repository errors raised by IFileRepository to be reraised, and all
other, unexpected errors to be reraised as RetrievalError.

monkey/monkey_island/cc/repository/file_agent_log_repository.py

@@ -2,7 +2,12 @@ import io
 import re
 
 from monkey_island.cc.models import AgentID
-from monkey_island.cc.repository import IAgentLogRepository, IFileRepository, RetrievalError
+from monkey_island.cc.repository import (
+    IAgentLogRepository,
+    IFileRepository,
+    RepositoryError,
+    RetrievalError,
+)
 
 AGENT_LOG_FILE_NAME_PATTERN = "agent-*.log"
 AGENT_LOG_FILE_NAME_REGEX = re.compile(r"^agent-[\w-]+.log$")
@@ -22,6 +27,8 @@ class FileAgentLogRepository(IAgentLogRepository):
             with self._file_repository.open_file(self._get_agent_log_file_name(agent_id)) as f:
                 log_contents = f.read().decode()
                 return log_contents
+        except RepositoryError as err:
+            raise err
         except Exception as err:
             raise RetrievalError(f"Error retrieving the agent logs: {err}")
 

monkey/tests/unit_tests/monkey_island/cc/repository/test_file_agent_log_repository.py

@@ -1,9 +1,16 @@
+import io
+from unittest.mock import MagicMock
 from uuid import UUID
 
 import pytest
 from tests.monkey_island import OpenErrorFileRepository, SingleFileRepository
 
-from monkey_island.cc.repository import FileAgentLogRepository, RetrievalError
+from monkey_island.cc.repository import (
+    FileAgentLogRepository,
+    IFileRepository,
+    RetrievalError,
+    UnknownRecordError,
+)
 
 LOG_CONTENTS = "lots of useful information"
 AGENT_ID = UUID("6bfd8b64-43d8-4449-8c70-d898aca74ad8")
@@ -22,7 +29,7 @@ def test_store_agent_log(repository):
 
 
 def test_get_agent_log__unknown_record_error(repository):
-    with pytest.raises(RetrievalError):
+    with pytest.raises(UnknownRecordError):
         repository.get_agent_log(AGENT_ID)
 
 
@@ -32,8 +39,17 @@ def test_get_agent_log__retrieval_error():
         repository.get_agent_log(AGENT_ID)
 
 
+def test_get_agent_log__corrupt_data():
+    file_repository = MagicMock(spec=IFileRepository)
+    file_repository.open_file = MagicMock(return_value=io.BytesIO(b"\xff\xfe"))
+    repository = FileAgentLogRepository(file_repository)
+
+    with pytest.raises(RetrievalError):
+        repository.get_agent_log(AGENT_ID)
+
+
 def test_reset_agent_logs(repository):
     repository.upsert_agent_log(AGENT_ID, LOG_CONTENTS)
     repository.reset()
-    with pytest.raises(RetrievalError):
+    with pytest.raises(UnknownRecordError):
         repository.get_agent_log(AGENT_ID)