fix fluent-bit output plugin generating invalid JSON #3240
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created an issue that further explains this problem at #3245 |
cyriltovena
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Jan 27, 2021
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Do you need any input from me here? |
cyriltovena
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Feb 15, 2021
* fix fluent-bit output plugin generating invalid JSON * fix golint error
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What this PR does / why we need it:
The fluent-bit output plugin incorrectly unescapes nested strings when generating JSON records. This leads to records with invalid JSON being sent to Loki, which are then no longer easily parsable with the json pipeline step as they lead to a JSON parser error in Loki's logql processor.
I added a unit-test for one of the, slightly modified, log lines that yielded the error on my fluent-bit/loki deployment, asserting a properly escaped JSON record.
An easy reproducer would be:
kuberneteskey by removing it from this list: https://github.com/grafana/helm-charts/blob/main/charts/fluent-bit/values.yaml#L20jsonstepWhich issue(s) this PR fixes:
None that i'm aware of
Special notes for your reviewer:
I'm honestly not sure whether the lineReplacer invocation has valid cases for JSON records. As of now, i can't think of a reason why it would be necessary/valid to un-escape any data in a JSON record, and the records generated with this fix are actually parse-able in Loki afterwards.
TBD:
I'll verify whether this changes the records generated by the default values.yaml of the FLB chart in any way. (which only pass thelogfield to Loki)-> From my tests with and without this change with the default config, the records remain the same, so it only has any effect when wrapping extra labels in a record. Therefore this change has no unwanted side-effects IMO.
Checklist
closes #3245