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Werk #19541: Relay installer: refresh systemd units without re-registering

Component Relay
Title Relay installer: refresh systemd units without re-registering
Date Jul 7, 2026
Level Prominent Change
Class New Feature
Compatibility Compatible - no manual interaction needed
Checkmk versions & editions
3.0.0b1
Not yet released
Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT
2.5.0p9
Not yet released
Checkmk Ultimate, Checkmk Cloud, Checkmk Ultimate MT

The relay installer (install_relay.sh) is the only component that writes a relay's host-side systemd units and its update-manager script. Until now, the only way to refresh those files was a full re-install - which re-registers the relay. As a result, fixes to the units or to the update logic could not reach relays already deployed in the field without disrupting their registration.

You can now refresh a relay's systemd units and update-manager script in place. Download the current installer from your site and run it with the new --update-systemd option:

sudo ./install_relay.sh --update-systemd

This rewrites the host-side files and restarts the relay container, while leaving the relay's registration and internal configuration untouched. The relay's current network mode is preserved automatically; pass --use-host-network to force host networking. The container image version is not touched - image updates keep using the existing mechanism.

Note: install, uninstall, and --update-systemd are now mutually exclusive modes. Combining them, or mixing registration arguments with uninstall or update, is rejected.

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