Add check output to history

[ultrotter]

This can be useful for example to have a perspective on a flapping check. In term of storage history is only kept for 20 runs, so the extra space is not meaningful. Alternatives could be a configuration per-sensu or per-check to store this field or not, or simply if one has too verbose checks trim them or silence the output for them and just rely on status.

Just adding the output is a very small change (per #24) with most code changes being the result of compiling the proto.

Could we please discuss pros and cons, and see if we can get to include this functionality? Thanks!

Guido

[ultrotter]

Hi! Is there any chance to discuss this issue, and its associated one liner fix, please?

[sourabhpatel-sumo]

Answered in detail on #24. Short version: accepted, but as the per-check opt-in you proposed rather than unconditionally — unconditional output-in-history defeats max_output_size and can push events past etcd's request ceiling, which is a hard reject that drops the event instead of truncating it.

The corev2 half lands here: CheckHistory.output, store_output_history on CheckConfig + Check, and the gate inside MergeWith. The truncation-ordering fix and the etcd budget land in sensu-go.

Tracking in sensu/sensu-go#5103. Leaving this open until the PR merges.