Werk #18758: REST API: fix 500 error when reading a folder with OpenTelemetry data enabled
| Component | REST API | ||||
| Title | REST API: fix 500 error when reading a folder with OpenTelemetry data enabled | ||||
| Date | Jul 21, 2026 | ||||
| Level | Trivial Change | ||||
| Class | Bug Fix | ||||
| Compatibility | Compatible - no manual interaction needed | ||||
| Checkmk versions & editions |
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Enabling "OpenTelemetry data" on a folder sets its metrics_association
attribute. Afterwards, requesting that folder via the REST API
(GET /objects/folder_config/{folder}, as well as the folder collection)
returned a 500 Internal Server Error with the message
"Mismatch between endpoint and internal data format." / "Not a valid string.".
The folder attribute schema did not declare a field for metrics_association,
so its value (a structured tuple) was routed through the generic custom-attribute
handling, which expects plain strings, and serialization failed.
The folder schemas now expose metrics_association in the same way the host
schemas already do. Reading, creating and updating folders with
metrics_association set (both "enabled" and "disabled") now works and round-trips
correctly.