Use properties.

samples/hello/README.md

@@ -1,5 +1,13 @@
+- [Hello World](#hello-world)
+    - [Start OpenSearch](#start-opensearch)
+    - [Start the Extension](#start-the-extension)
+    - [Register the Extension](#register-the-extension)
+    - [Call an Extension API](#call-an-extension-api)
+
 # Hello World
 
+This sample implements an extension that exposes a REST API.
+
 ### Start OpenSearch
 
 Enable the `opensearch.experimental.feature.extensions.enabled` experimental feature in either way described in [the developer guide](https://github.com/opensearch-project/opensearch-sdk-java/blob/main/DEVELOPER_GUIDE.md#enable-the-extensions-feature-flag).
@@ -80,4 +88,18 @@ INFO:root:< prefix=b'ES', version=2.10.0.99, type=['request'], message=50 byte(s
 INFO:root:> prefix=b'ES', version=2.10.0.99, type=['response'], message=179 byte(s), id=9, ctx=req={}, res={}, id=hello-world, version=3.0.0.99, name=hello-world, host=127.0.0.1, addr=127.0.0.1, attr={}, roles={('data', 'd', True), ('ingest', 'i', False), ('remote_cluster_client', 'r', False), ('cluster_manager', 'm', False)}, cluster name=, version=3.0.0.99, features=[], size=185 byte(s)
 INFO:root:< prefix=b'ES', version=2.10.0.99, type=['request'], message=469 byte(s), id=10, ctx=req={'_system_index_access_allowed': 'false'}, res={}, None, features=[], action=internal:discovery/extensions
 INFO:root:> prefix=b'ES', version=2.10.0.99, type=['response'], message=167 byte(s), id=6, ctx=req={'_system_index_access_allowed': 'false', 'extension_unique_id': 'hello-world'}, res={}, node=, id=None, features=[], action=internal:discovery/registerrestactions, size=173 byte(s)
-```
+```
+
+### Call an Extension API
+
+```bash
+curl -XGET "localhost:9200/_extensions/_hello-world/hello"
+Hello from Python! 👋
+```
+
+OpenSearch invokes an extension endpoint, and you should see some output there.
+
+```
+INFO:root:< prefix=b'ES', version=2.10.0.99, type=['request'], message=161 byte(s), id=15, ctx=req={'_system_index_access_allowed': 'false'}, res={}, None, features=[], action=internal:extensions/restexecuteonextensiontaction
+INFO:root:> prefix=b'ES', version=2.10.0.99, type=['response'], message=108 byte(s), id=15, ctx=req={'_system_index_access_allowed': 'false'}, res={}, <opensearch_sdk_py.rest.rest_execute_on_extension_response.RestExecuteOnExtensionResponse object at 0x1048cb450>, features=[], size=114 byte(s)
+```

samples/hello/hello.py

@@ -98,13 +98,13 @@ async def run_server() -> None:
 # TODO Move this code to SDK "runner" class
 # Map interface name to instance
 interfaces = dict()
-for interface in extension.get_implemented_interfaces():
+for interface in extension.implemented_interfaces:
     interfaces[interface[0]] = interface[1]
     logging.info(f"Registering {interface[0]} to point to {interface[1]}")
 # If it's an ActionExtension it has this extension point
 # TODO This could perhaps be better with isinstance()
 if "ActionExtension" in interfaces.keys():
-    for handler in getattr(interfaces["ActionExtension"], "get_extension_rest_handlers")():
+    for handler in getattr(interfaces["ActionExtension"], "extension_rest_handlers"):
         ExtensionRestHandlers().register(handler)
         logging.info(f"Registering {handler}")
 

samples/hello/hello_extension.py

@@ -16,13 +16,15 @@
 
 
 class HelloExtension(Extension, ActionExtension):
-    def get_implemented_interfaces(self) -> list[tuple]:
+    @property
+    def implemented_interfaces(self) -> list[tuple]:
         # TODO: This is lazy and temporary.
         # Really we should be using this class to call some SDK class run(),
         # passing an instance of ourself to the SDK and letting it parse out
         # the superclass names with class.__mro__ and calling the appropriate
         # implemented functions from the interfaces.
         return [("Extension", self), ("ActionExtension", self)]
 
-    def get_extension_rest_handlers(self) -> list[ExtensionRestHandler]:
+    @property
+    def extension_rest_handlers(self) -> list[ExtensionRestHandler]:
         return [HelloRestHandler()]

samples/hello/hello_rest_handler.py

@@ -25,5 +25,6 @@ def handle_request(self, rest_request: ExtensionRestRequest) -> ExtensionRestRes
         response_bytes = bytes("Hello from Python!", "utf-8") + b"\x20\xf0\x9f\x91\x8b"
         return ExtensionRestResponse(RestStatus.OK, response_bytes, ExtensionRestResponse.TEXT_CONTENT_TYPE)
 
+    @property
     def routes(self) -> list[NamedRoute]:
         return [NamedRoute(method=RestMethod.GET, path="/hello", unique_name="greeting")]

src/opensearch_sdk_py/actions/internal/discovery_extensions_request_handler.py

@@ -40,7 +40,7 @@ def handle(self, request: OutboundMessageRequest, input: StreamInput) -> StreamO
             OutboundMessageRequest(
                 thread_context=request.thread_context_struct,
                 features=request.features,
-                message=RegisterRestActionsRequest("hello-world", ExtensionRestHandlers().named_routes()),
+                message=RegisterRestActionsRequest("hello-world", ExtensionRestHandlers().named_routes),
                 version=request.version,
                 action="internal:discovery/registerrestactions",
                 is_handshake=False,

src/opensearch_sdk_py/api/action_extension.py

@@ -15,8 +15,9 @@
 
 
 class ActionExtension(ABC):
+    @property
     @abstractmethod
-    def get_extension_rest_handlers(self) -> list[ExtensionRestHandler]:
+    def extension_rest_handlers(self) -> list[ExtensionRestHandler]:
         """
         Implementer should return a list of classes implementing ExtensionRestHandler
         """

src/opensearch_sdk_py/api/extension.py

@@ -13,8 +13,9 @@
 
 
 class Extension(ABC):
+    @property
     @abstractmethod
-    def get_implemented_interfaces(self) -> list[tuple]:
+    def implemented_interfaces(self) -> list[tuple]:
         """
         Implementer should return a list of tuples containing the implemented interface (such as
         Extension, ActionExtension, etc.) and the implementing class.

src/opensearch_sdk_py/rest/extension_rest_handler.py

@@ -19,7 +19,8 @@
 class ExtensionRestHandler(ABC):
     @abstractmethod
     def handle_request(rest_request: ExtensionRestRequest) -> ExtensionRestResponse:
         pass
 
+    @property
     def routes(self) -> list[NamedRoute]:
         return []

src/opensearch_sdk_py/rest/extension_rest_handlers.py

@@ -24,12 +24,13 @@ def __new__(cls):  # type:ignore
         return cls._singleton
 
     def register(self, klass: ExtensionRestHandler) -> None:
-        for route in getattr(klass, "routes")():
+        for route in klass.routes:
             # for matching the handler on the extension side only method and path matter
             self[route.key] = klass
             # but we have to send the full named route to OpenSearch
             self._named_routes.append(str(route))
 
+    @property
     def named_routes(self) -> list[str]:
         return self._named_routes
 

tests/rest/test_extension_rest_handlers.py

@@ -25,7 +25,7 @@ def test_registers_handler(self) -> None:
         self.assertEqual(len(ExtensionRestHandlers()), 2)
         self.assertIsInstance(ExtensionRestHandlers()["GET /foo"], FakeRestHandler)
         self.assertIsInstance(ExtensionRestHandlers()["GET /bar"], FakeRestHandler)
-        self.assertListEqual(ExtensionRestHandlers().named_routes(), ["GET /foo get_foo", "GET /bar get_bar"])
+        self.assertListEqual(ExtensionRestHandlers().named_routes, ["GET /foo get_foo", "GET /bar get_bar"])
 
         response = handlers.handle("GET /foo", ExtensionRestRequest())
         self.assertEqual(response.status, RestStatus.NOT_IMPLEMENTED)
@@ -38,5 +38,6 @@ def __init__(self) -> None:
     def handle_request(self, rest_request: ExtensionRestRequest) -> ExtensionRestResponse:
         return ExtensionRestResponse(status=RestStatus.NOT_IMPLEMENTED)
 
+    @property
     def routes(self) -> list[NamedRoute]:
         return [NamedRoute(RestMethod.GET, "/foo", "get_foo"), NamedRoute(RestMethod.GET, "/bar", "get_bar")]