fix(kea driver): fix broken retry logic in _make_request

The success return was outside the try/except but inside the attempt
loop, so it always returned (or raised IndexError) after the first
attempt regardless of success. Retries never actually ran, silently
dropping reservations for ports that hit a transient request failure.

Author: skrobul

python/ironic-understack/ironic_understack/dhcp/kea.py

@@ -43,6 +43,7 @@ def _make_request(self, command, arguments, services=None):
             "arguments": arguments,
         }
 
+        last_exception = None
         for attempt in range(self.max_retries):
             results = []
             try:
@@ -58,26 +59,33 @@ def _make_request(self, command, arguments, services=None):
                     )
                     response.raise_for_status()
                     results.append(response)
-            except requests.exceptions.Timeout:
+                return results[0].json()
+            except requests.exceptions.Timeout as e:
+                last_exception = e
                 LOG.warning(
                     "Timeout on attempt %d/%d for command %s",
                     attempt + 1,
                     self.max_retries,
                     command,
                 )
             except requests.exceptions.RequestException as e:
-                if attempt == self.max_retries - 1:
-                    LOG.error("Failed to execute command %s: %s", command, e)
-                    raise DHCPConfigurationError(
-                        f"Failed to execute {command}: {e}"
-                    ) from e
+                last_exception = e
                 LOG.warning(
                     "Request failed on attempt %d/%d: %s",
                     attempt + 1,
                     self.max_retries,
                     e,
                 )
-            return results[0].json()
+
+        LOG.error(
+            "Failed to execute command %s after %d attempts: %s",
+            command,
+            self.max_retries,
+            last_exception,
+        )
+        raise DHCPConfigurationError(
+            f"Failed to execute {command}: {last_exception}"
+        ) from last_exception
 
     def get_config(self):
         """Retrieve current Kea configuration."""

python/ironic-understack/ironic_understack/tests/test_dhcp_kea.py

@@ -0,0 +1,70 @@
+from unittest.mock import Mock
+
+import pytest
+import requests
+
+from ironic_understack.dhcp.kea import DHCPConfigurationError
+from ironic_understack.dhcp.kea import KeaDHCPApi
+
+
+@pytest.fixture
+def kea(mocker):
+    api = KeaDHCPApi()
+    api.max_retries = 3
+    mocker.patch.object(api, "_lookup_api_urls", return_value=["http://kea"])
+    return api
+
+
+def _response(payload):
+    response = Mock()
+    response.raise_for_status.return_value = None
+    response.json.return_value = payload
+    return response
+
+
+def test_make_request_retries_after_transient_timeout(kea, mocker):
+    post = mocker.patch(
+        "ironic_understack.dhcp.kea.requests.post",
+        side_effect=[requests.exceptions.Timeout(), _response({"result": 0})],
+    )
+
+    result = kea._make_request("config-get", {})
+
+    assert result == {"result": 0}
+    assert post.call_count == 2
+
+
+def test_make_request_raises_after_exhausting_retries(kea, mocker):
+    post = mocker.patch(
+        "ironic_understack.dhcp.kea.requests.post",
+        side_effect=requests.exceptions.ConnectionError("boom"),
+    )
+
+    with pytest.raises(DHCPConfigurationError):
+        kea._make_request("config-get", {})
+
+    assert post.call_count == kea.max_retries
+
+
+def test_make_request_raises_after_exhausting_timeouts(kea, mocker):
+    post = mocker.patch(
+        "ironic_understack.dhcp.kea.requests.post",
+        side_effect=requests.exceptions.Timeout(),
+    )
+
+    with pytest.raises(DHCPConfigurationError):
+        kea._make_request("config-get", {})
+
+    assert post.call_count == kea.max_retries
+
+
+def test_make_request_succeeds_on_first_attempt(kea, mocker):
+    post = mocker.patch(
+        "ironic_understack.dhcp.kea.requests.post",
+        return_value=_response({"result": 0}),
+    )
+
+    result = kea._make_request("config-get", {})
+
+    assert result == {"result": 0}
+    assert post.call_count == 1