Werk #19327: systemd unit: emit one host label per discovered unit
| Component | Checks & agents | ||||
| Title | systemd unit: emit one host label per discovered unit | ||||
| Date | Jul 1, 2026 | ||||
| Level | Trivial Change | ||||
| Class | Bug Fix | ||||
| Compatibility | Incompatible - Manual interaction might be required | ||||
| Checkmk versions & editions |
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When the Systemd Service Summary discovery rule is configured to create host
labels for discovered units, Checkmk previously created a single host label of the
form cmk/systemd/unit:<name> for each unit.
Since a host label key can only carry one value, hosts running more than one discovered systemd unit could not hold a distinct label per unit — the units overwrote each other and could not be addressed individually in label conditions.
With this werk, each discovered unit now gets its own boolean host label in the
form cmk/systemd/unit/<name>:yes. For example, a host running the apache and
nginx units now carries both cmk/systemd/unit/apache:yes and
cmk/systemd/unit/nginx:yes, so each unit can be targeted independently.
This change is incompatible: existing rules, host and service conditions, views and
filters that reference the old cmk/systemd/unit:<name> label will no longer match.
Update them to the new cmk/systemd/unit/<name>:yes form. The affected labels are
re-created automatically on the next service discovery / host label update.