Werk #18557: HPE StoreOnce via REST API 4.x: fix crash while collecting monitoring data

Component

Checks & agents

Title

HPE StoreOnce via REST API 4.x: fix crash while collecting monitoring data

Date

May 31, 2026

Level

Trivial Change

Class

Bug Fix

Compatibility

Compatible - no manual interaction needed

Checkmk versions & editions

3.0.0b1 Not yet released	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p6	Checkmk Community, Checkmk Pro, Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

After upgrading from 2.4.0 to 2.5.0, the special agent configured via the rule HPE StoreOnce via REST API 4.x crashed and produced no monitoring data, reporting:

TypeError: Object of type generator is not JSON serializable

The data fetched from the StoreOnce REST API was no longer serialized correctly before being written to the agent output.

The agent now writes one JSON object per line again, as the StoreOnce check plugins expect, and the check works again after the upgrade.

To the list of all Werks