fix(gateway): catch JSONDecodeError Requests<2.27

Catch JSONDecodeError from simpleson external library and json
standard library module, with the logic required with Requests < 2.27.

CHANGELOG.md

@@ -76,9 +76,12 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
   - Fix compatibility issue with Requests >= 2.32.2 (#350).
   - Return HTTP/404 not found with meaningful error message when requesting
     unexisting node.
-- gateway: catch generic `requests.exceptions.RequestException` when retrieving
-  information from agents to avoid `AttributeError` with more specific
-  exceptions on old versions on _Requests_ library (#391).
+- gateway:
+  - Catch generic `requests.exceptions.RequestException` when retrieving
+    information from agents to avoid `AttributeError` with more specific
+    exceptions on old versions on _Requests_ library (#391).
+  - Catch `JSONDecodeError` from _simpleson_ external library and _json_
+    standard library module not managed by Requests < 2.27.
 - frontend: Update dependencies to fix CVE-2024-45812 and CVE-2024-45811 (vite),
   CVE-2024-47068 (rollup).
 

slurmweb/apps/gateway.py

@@ -14,7 +14,11 @@
 from . import SlurmwebWebApp
 from ..views import SlurmwebAppRoute
 from ..views import gateway as views
-from ..errors import SlurmwebConfigurationError, SlurmwebAgentError
+from ..errors import (
+    SlurmwebConfigurationError,
+    SlurmwebCompatJSONDecodeError,
+    SlurmwebAgentError,
+)
 
 logger = logging.getLogger(__name__)
 
@@ -86,6 +90,7 @@ def agents(self):
                 agent = self._agent_info(url.geturl())
             except (
                 requests.exceptions.RequestException,
+                SlurmwebCompatJSONDecodeError,
                 SlurmwebAgentError,
             ) as err:
                 logger.error(

slurmweb/errors.py

@@ -27,3 +27,19 @@ class SlurmwebCacheError(Exception):
 
 class SlurmwebMetricsDBError(Exception):
     pass
+
+
+# Alias JSONDecodeError from simplejson external library and json standard library
+# module to catch generically the error raised with Requests < 2.27 on old systems in
+# presence of unexepected non-JSON responses.
+#
+# This is not needed with Requests >= 2.27 where the same logic is implemented with
+# requests.exceptions.JSONDecodeError wildcard exception. For reference, see:
+# https://github.com/psf/requests/pull/5856
+
+try:
+    from simplejson import JSONDecodeError
+except ImportError:
+    from json import JSONDecodeError
+
+SlurmwebCompatJSONDecodeError = JSONDecodeError