Werk #19432: Fix "Monitor specific TCP/UDP connections and listeners" rule editor
| Component | Checks & agents | ||||
| Title | Fix "Monitor specific TCP/UDP connections and listeners" rule editor | ||||
| Date | Apr 29, 2026 | ||||
| Level | Trivial Change | ||||
| Class | Bug Fix | ||||
| Compatibility | Incompatible - Manual interaction might be required | ||||
| Checkmk versions & editions |
|
Editing, saving, or creating a rule under Monitor specific TCP/UDP connections and listeners on Checkmk 2.5 versions was broken in two ways:
- Existing rules carried over from 2.4 displayed an unselectable hash placeholder in the State dropdown instead of the previously chosen value.
- Saving a rule (whether modified or freshly created) wrote an invalid rule configuration to disk. Subsequent configuration activations, HW/SW inventory, and the rule editor itself all failed, often surfacing as Error running automation call update-passwords-merged-file during activation.
This has been fixed: the rule editor now stores the connection state correctly, and existing 2.4 rules render correctly again.
If you already saved a rule on a 2.5 version and activation now
fails, manually edit the affected etc/check_mk/conf.d/wato/...mk
file and replace each <ConnectionState.X: 'X'> with 'X', or
delete and re-create the rule.
Technical background
The chosen state was persisted as a ConnectionState enum member,
which serialised as <ConnectionState.ESTABLISHED: 'ESTABLISHED'>
instead of the plain string 'ESTABLISHED'. The resulting file was
no longer valid Python and could not be loaded.