fix(OPENFRAM-002-9): CU-86akdyq05 MachineHostnameListener leaves the message unacked on any parse or extraction error, risking infinite redelivery

[flamingo]

Closes findings from rule OPENFRAM-002-9 — MachineHostnameListener leaves the message unacked on any parse or extraction error, risking infinite redelivery.

Draft — this is a starting point, not a finished change. The fix required judgment, so read it before trusting it.

#	Fix confidence	Finding	Location
1	🔴 55 low — review closely	MachineHostnameListener leaves the message unacked on any parse or extraction error, risking infinite redelivery	openframe-client-core/src/main/java/com/openframe/client/listener/MachineHostnameListener.java:84

What changed — and what was deliberately left — is explained per finding as inline review comments on the lines each finding touched.

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Run: https://product-hub.flamingo.so/admin/code-review
Run id: 4f0d6344-55d4-49de-bc86-cac2510f432f

Merging this PR is recorded as acceptance of the rule that produced it;
closing it unmerged is recorded as rejection. Both feed rule health, so
closing a wrong suggestion is useful rather than merely tidy.

ClickUp task: CU-86akdyq05 OpenFrame message ack and IAM pattern fixes (4 PRs)

[flamingo]

🦩 What this fix changed, finding by finding

1 finding(s) fixed in this draft — 1 explained inline on the diff; 1 low-confidence hunk(s) need close review before merging.

[flamingo]

🦩 🟠 MachineHostnameListener leaves the message unacked on any parse or extraction error, risking infinite redelivery

In handleMessage, added a new catch (JsonProcessingException | IllegalArgumentException e) block (before the generic catch (Exception e)) that logs and calls message.ack() instead of leaving the message unacked. This targets the specific permanent-failure cases called out in the finding: malformed JSON (JsonProcessingException from objectMapper.readValue) and malformed subject (assuming machineIdExtractor.extract throws IllegalArgumentException on an unparseable subject, which is a common convention but not verified against that class's actual implementation in this file). Also added the com.fasterxml.jackson.core.JsonProcessingException import. The remaining generic Exception catch still leaves messages unacked for genuinely transient errors (e.g. machineHostnameService.updateHostname failures), preserving existing redelivery behavior for those. A complete fix would require confirming the actual exception type(s) thrown by NatsTopicMachineIdExtractor.extract for malformed subjects and verifying updateHostname's failure modes to ensure no permanent-failure exceptions leak into the unbounded-retry path.

🤖 Prompt for AI agents

In openframe-client-core/src/main/java/com/openframe/client/listener/MachineHostnameListener.java around line 84, review and complete this code-review fix: MachineHostnameListener leaves the message unacked on any parse or extraction error, risking infinite redelivery.
What the draft fix changed: In `handleMessage`, added a new `catch (JsonProcessingException | IllegalArgumentException e)` block (before the generic `catch (Exception e)`) that logs and calls `message.ack()` instead of leaving the message unacked. This targets the specific permanent-failure cases called out in the finding: malformed JSON (`JsonProcessingException` from `objectMapper.readValue`) and malformed subject (assuming `machineIdExtractor.extract` throws `IllegalArgumentException` on an unparseable subject, which is a common convention but not verified against that class's actual implementation in this file). Also added the `com.fasterxml.jackson.core.JsonProcessingException` import. The remaining generic `Exception` catch still leaves messages unacked for genuinely transient errors (e.g. `machineHostnameService.updateHostname` failures), preserving existing redelivery behavior for those. A complete fix would require confirming the actual exception type(s) thrown by `NatsTopicMachineIdExtractor.extract` for malformed subjects and verifying `updateHostname`'s failure modes to ensure no permanent-failure exceptions leak into the unbounded-retry path.
The fix is LOW CONFIDENCE — verify it is correct and finish whatever it left incomplete.

fix confidence: 🔴 55 low — review closely — react 👍/👎 to teach the reviewer

[michaelassraf]

Task linked: CU-86akdyq05 OpenFrame message ack and IAM pattern fixes (4 PRs)