feat: ✨ Discover registered links when available (#112)

- add links map to the discovery model
- load links when the discover is called

As Links are new addtion to the API, we do not fail when server returns 404 and only have no links available. All this to have backward compatibility.

RESOLVES h2oai/cloud-discovery#694

src/h2o_discovery/_internal/load.py

@@ -2,6 +2,7 @@
 import os
 import types
 from typing import Iterable
+from typing import List
 from typing import Mapping
 from typing import Optional
 
@@ -18,11 +19,13 @@ def load_discovery(cl: client.Client) -> model.Discovery:
         environment = cl.get_environment()
         services = _get_service_map(cl.list_services())
         clients = _get_client_map(cl.list_clients())
+        links = _get_link_map(_list_links(cl))
     except Exception as e:
         _handle_specific_client_exceptions(e)
         raise
-
-    return model.Discovery(environment=environment, services=services, clients=clients)
+    return model.Discovery(
+        environment=environment, services=services, clients=clients, links=links
+    )
 
 
 async def load_discovery_async(cl: client.AsyncClient) -> model.Discovery:
@@ -31,11 +34,36 @@ async def load_discovery_async(cl: client.AsyncClient) -> model.Discovery:
         environment = await cl.get_environment()
         services = _get_service_map(await cl.list_services())
         clients = _get_client_map(await cl.list_clients())
+        links = _get_link_map(await _list_links_async(cl))
     except Exception as e:
         _handle_specific_client_exceptions(e)
         raise
 
-    return model.Discovery(environment=environment, services=services, clients=clients)
+    return model.Discovery(
+        environment=environment, services=services, clients=clients, links=links
+    )
+
+
+def _list_links(cl: client.Client) -> List[model.Link]:
+    try:
+        return cl.list_links()
+    except Exception as e:
+        # Links are added in the server version 2.5.0. In order to have client that
+        # is backwards compatible, we won't fail if the links are not available.
+        if isinstance(e, httpx.HTTPStatusError) and e.response.status_code == 404:
+            return []
+        raise
+
+
+async def _list_links_async(cl: client.AsyncClient) -> List[model.Link]:
+    try:
+        return await cl.list_links()
+    except Exception as e:
+        # Links are added in the server version 2.5.0. In order to have client that
+        # is backwards compatible, we won't fail if the links are not available.
+        if isinstance(e, httpx.HTTPStatusError) and e.response.status_code == 404:
+            return []
+        raise
 
 
 def load_credentials(
@@ -71,6 +99,13 @@ def _get_client_map(clients: Iterable[model.Client]) -> Mapping[str, model.Clien
     return types.MappingProxyType(out)
 
 
+def _get_link_map(links: Iterable[model.Link]) -> Mapping[str, model.Link]:
+    out = {}
+    for ln in links:
+        out[_link_key(ln.name)] = ln
+    return types.MappingProxyType(out)
+
+
 _SERVICES_COLLECTION_PREFIX = "services/"
 
 
@@ -89,6 +124,15 @@ def _client_key(name: str) -> str:
     raise ValueError(f"invalid client name: {name}")
 
 
+_LINKS_COLLECTION_PREFIX = "links/"
+
+
+def _link_key(name: str) -> str:
+    if name.startswith(_LINKS_COLLECTION_PREFIX):
+        return name[len(_LINKS_COLLECTION_PREFIX) :]
+    raise ValueError(f"invalid link name: {name}")
+
+
 _ENV_ERROR = error.H2OCloudEnvironmentError(
     "Received an unexpected response from the server."
     " Please make sure that the environment you are trying to connect to is"

src/h2o_discovery/model.py

@@ -167,6 +167,9 @@ class Discovery:
     #: Map of registered clients in the `{"client-identifier": Client(...)}` format.
     clients: Mapping[str, Client]
 
+    #: Map of registered links in the `{"link-identifier": Link(...)}` format.
+    links: Mapping[str, Link]
+
     #: Map of credentials in the `{"client-identifier": Credentials(...)}` format.
     credentials: Mapping[str, Credentials] = dataclasses.field(
         default_factory=_empty_credentials_factory

tests/_internal/load/test_load_discovery.py

@@ -1,6 +1,7 @@
 import asyncio
 from unittest import mock
 
+import httpx
 import pytest
 
 from h2o_discovery import model
@@ -15,6 +16,8 @@ def mock_async_client():
     client.list_services.return_value.set_result({})
     client.list_clients.return_value = asyncio.Future()
     client.list_clients.return_value.set_result({})
+    client.list_links.return_value = asyncio.Future()
+    client.list_links.return_value.set_result({})
 
     return client
 
@@ -25,6 +28,7 @@ def mock_sync_client():
     client.list_services.return_value = {}
     client.list_clients.return_value = {}
     client.list_clients.return_value = {}
+    client.list_links.return_value = {}
 
     return client
 
@@ -130,3 +134,65 @@ async def test_load_clients_async():
 
     # Then
     assert discovery.clients["test-client"] == CLIENT_RECORD
+
+
+LINK_RECORD = model.Link(
+    name="links/test-link", uri="http://test-link.domain:1234", text="Test Link"
+)
+
+
+def test_load_links():
+    # Given
+    mock_client = mock_sync_client()
+    mock_client.list_links.return_value = [LINK_RECORD]
+
+    # When
+    discovery = load.load_discovery(mock_client)
+
+    # Then
+    assert discovery.links["test-link"] == LINK_RECORD
+
+
+@pytest.mark.asyncio
+async def test_load_links_async():
+    # Given
+    mock_client = mock_async_client()
+    mock_client.list_links.return_value = asyncio.Future()
+    mock_client.list_links.return_value.set_result([LINK_RECORD])
+
+    # When
+    discovery = await load.load_discovery_async(mock_client)
+
+    # Then
+    assert discovery.links["test-link"] == LINK_RECORD
+
+
+def test_load_links_not_found_returns_empty_map():
+    # Given
+    not_found_exception = httpx.HTTPStatusError(
+        "Test Error", request=mock.Mock(), response=mock.Mock(status_code=404)
+    )
+    mock_client = mock_sync_client()
+    mock_client.list_links.side_effect = not_found_exception
+
+    # When
+    discovery = load.load_discovery(mock_client)
+
+    # Then
+    assert discovery.links == {}
+
+
+@pytest.mark.asyncio
+async def test_load_links_async_not_found_returns_empty_map():
+    # Given
+    not_found_exception = httpx.HTTPStatusError(
+        "Test Error", request=mock.Mock(), response=mock.Mock(status_code=404)
+    )
+    mock_client = mock_async_client()
+    mock_client.list_links.side_effect = not_found_exception
+
+    # When
+    discovery = await load.load_discovery_async(mock_client)
+
+    # Then
+    assert discovery.links == {}