Issue-35: Add save and restore capabilities to Settings

src/common/schema.py

@@ -213,6 +213,22 @@ class Settings(BaseModel):
     rag: Optional[RagSettings] = Field(default_factory=RagSettings, description="RAG Settings")
     oci: Optional[OciSettings] = Field(default_factory=OciSettings, description="OCI Settings")
 
+    @classmethod
+    def from_json(cls, client: str, json: str):
+        """Create instance from JSON or defaults, if JSON fails to validate"""
+        try:
+            tmp_settings = cls.model_validate_json(json)
+            tmp_settings.client = client
+            return tmp_settings
+        except ValueError as e:
+            return cls(client=client)
+
+
+    def json_to_file(self, settings_file: str):
+        """Store settings to file at given path."""
+        with open(settings_file, 'w') as file:
+            settings_json = file.write(self.model_dump_json())
+
 
 #####################################################
 # Completions

src/server/bootstrap/settings_def.py

@@ -5,14 +5,45 @@
 
 from common.schema import Settings
 import common.logging_config as logging_config
+import os
 
 logger = logging_config.logging.getLogger("server.bootstrap.settings_def")
 
+def _settings_path() -> str:
+    """Return the path where settings should be stored.
+
+    It assumes that this module is in src/server/bootsrap and removes
+    "server/bootstrap/settings_def.py" from the path.
+    """
+    src_dir_comps = __file__.split(os.sep)[:-3]
+    src_dir_comps.extend(["etc", "settings.json"])
+
+    return os.sep.join(src_dir_comps)
+
+
+# SETTIGS_PATH is computed once the first time this module is loaded
+SETTINGS_PATH = _settings_path()
+
+def restore_or_default_settings(client: str, settings_file: str = SETTINGS_PATH) -> Settings:
+    """Return a Settings instance restoring from JSON file or with default values.
+
+    Arguments
+    ---------
+    client -- Client unique identifier
+    settings_file -- Path to the settings file with default value, but can be injected for testing
+    """
+    if os.path.isfile(settings_file) and os.access(settings_file, os.R_OK):
+        with open(settings_file, 'r') as file:
+            settings_json = file.read()
+    else:
+        settings_json = ""
+    return Settings.from_json(client, settings_json)
+
 
 def main() -> list[Settings]:
     """Define example Settings Support"""
     clients = ["default", "server"]
-    settings_objects = [Settings(client=client) for client in clients]
+    settings_objects = [restore_or_default_settings(client=client) for client in clients]
     return settings_objects
 
 

tests/common/schema_test.py

@@ -0,0 +1,62 @@
+"""
+Copyright (c) 2024, 2025, Oracle and/or its affiliates.
+Licensed under the Universal Permissive License v1.0 as shown at http://oss.oracle.com/licenses/upl.
+"""
+
+from common.schema import Settings, LanguageModelParameters
+import pytest
+import unittest.mock as mock
+
+def test_create_settings_from_json_returns_right_settings():
+    json = """
+    { "client": "default",
+      "ll_model": { "context_length": null,
+                    "frequency_penalty": 0.0,
+                    "max_completion_tokens": 256,
+                    "presence_penalty": 0.0,
+                    "temperature": 1.2,
+                    "top_p": 1.0,
+                    "streaming": false,
+                    "model": null,
+                    "chat_history": true },
+      "prompts": { "ctx": "Basic Example",
+                   "sys": "Basic Example" },
+      "rag": { "database": "DEFAULT",
+               "vector_store": null,
+               "alias": null,
+               "model": null,
+               "chunk_size": null,
+               "chunk_overlap": null,
+               "distance_metric": null,
+               "index_type": null,
+               "rag_enabled": false,
+               "grading": true,
+               "search_type": "Similarity",
+               "top_k": 4,
+               "score_threshold": 0.0,
+               "fetch_k": 20,
+               "lambda_mult": 0.5 },
+      "oci": { "auth_profile" :"DEFAULT" }
+    }
+    """
+    client = "default"
+    settings_from_json = Settings.from_json(client, json)
+    some_settings = Settings(client=client)
+    some_settings.ll_model.temperature = 1.2
+    print(f"LEFT:  {settings_from_json}")
+    print(f"RIGHT: {some_settings}")
+    assert settings_from_json == some_settings
+
+
+def test_json_to_file_writes_settings_json():
+    client = "default"
+    path = 'some_path/some_file.json'
+    default_settings = Settings(client=client)
+    default_settings.ll_model.top_p = 0.5
+
+    mocked_open = mock.mock_open()
+    with mock.patch('builtins.open', mocked_open) as mock_open:
+        default_settings.json_to_file(path)
+        mock_open.assert_called_with(path, 'w')
+        mock_open().write.assert_called_once_with(default_settings.model_dump_json())
+

tests/server/bootstrap/settings_def_test.py

@@ -0,0 +1,119 @@
+"""
+Copyright (c) 2024, 2025, Oracle and/or its affiliates.
+Licensed under the Universal Permissive License v1.0 as shown at http://oss.oracle.com/licenses/upl.
+"""
+
+from server.bootstrap.settings_def import restore_or_default_settings
+from common.schema import Settings, LanguageModelParameters
+import pytest
+import os
+import unittest.mock as mock
+
+
+def test_restore_returns_default_settings_on_invalid_settings_file():
+    client = "default"
+    settings_from_json = restore_or_default_settings(client, "invalid_file.json")
+    default_settings = Settings(client=client)
+    assert settings_from_json == default_settings
+
+
+@pytest.mark.parametrize(('is_file', 'has_access', 'file_read'),
+    [
+        (True, True, True),
+        (False, True, False),
+        (True, False, False),
+        (False, False, False),
+     ])
+@mock.patch('os.access')
+@mock.patch('os.path.isfile')
+def test_restore_reads_file_if_isfile_and_has_access(mock_isfile, mock_access, is_file, has_access, file_read):
+    client = "default"
+    path = 'some_path/some_file.json'
+    mock_isfile.return_value = is_file
+    mock_access.return_value = has_access
+    mocked_open = mock.mock_open(read_data="")
+    with mock.patch('builtins.open', mocked_open) as mock_open:
+        settings_from_file = restore_or_default_settings(client, path)
+        if file_read:
+            mock_open.assert_called_with(path, 'r')
+
+    mock_isfile.assert_called_with(path)
+    if is_file:
+        mock_access.assert_called_with(path, os.R_OK)
+
+
+@mock.patch('os.access')
+@mock.patch('os.path.isfile')
+def test_restore_returns_default_settings_from_bad_json(mock_isfile, mock_access):
+    client = "default"
+    path = 'some_path/some_file.json'
+    json = """
+    { "client": "default",
+      "prompts": { "ctx": "Another Example",
+                   "sys": "Yet another Example" },
+      "nothing_else_here" }
+    """
+    mock_isfile.return_value = True
+    mock_access.return_value = True
+    mocked_open = mock.mock_open(read_data=json)
+    with mock.patch('builtins.open', mocked_open) as mock_open:
+        settings_from_file = restore_or_default_settings(client, path)
+        mock_open.assert_called_with(path, 'r')
+
+    default_settings = Settings(client=client)
+
+    mock_isfile.assert_called_once_with(path)
+    mock_access.assert_called_once_with(path, os.R_OK)
+    assert settings_from_file == default_settings
+
+
+@mock.patch('os.access')
+@mock.patch('os.path.isfile')
+def test_restore_returns_settings_from_json(mock_isfile, mock_access):
+    client = "default"
+    path = 'some_path/some_file.json'
+    json = """
+    { "client": "default",
+      "ll_model": { "context_length": null,
+                    "frequency_penalty": 0.0,
+                    "max_completion_tokens": 256,
+                    "presence_penalty": 0.0,
+                    "temperature": 1.2,
+                    "top_p": 1.0,
+                    "streaming": false,
+                    "model": null,
+                    "chat_history": true },
+      "prompts": { "ctx": "Basic Example",
+                   "sys": "Basic Example" },
+      "rag": { "database": "DEFAULT",
+               "vector_store": null,
+               "alias": null,
+               "model": null,
+               "chunk_size": null,
+               "chunk_overlap": null,
+               "distance_metric": null,
+               "index_type": null,
+               "rag_enabled": false,
+               "grading": true,
+               "search_type": "Similarity",
+               "top_k": 4,
+               "score_threshold": 0.0,
+               "fetch_k": 20,
+               "lambda_mult": 0.5 },
+      "oci": { "auth_profile" :"DEFAULT" }
+    }
+    """
+    mock_isfile.return_value = True
+    mock_access.return_value = True
+    mocked_open = mock.mock_open(read_data=json)
+    with mock.patch('builtins.open', mocked_open) as mock_open:
+        settings_from_file = restore_or_default_settings(client, path)
+        mock_open.assert_called_with(path, 'r')
+
+    default_settings = Settings(client=client)
+    default_settings.ll_model.temperature = 1.2
+
+    mock_isfile.assert_called_once_with(path)
+    mock_access.assert_called_once_with(path, os.R_OK)
+    assert settings_from_file == default_settings
+