Rules HTTP API weirdness: nulls, different values for "same" field, lastEvaluation set to 0000

[GiedriusS]

On top of:

b2f1485 from #2865

With:

TZ=UTC PROMETHEUS_EXECUTABLE=~/dev/prometheus/prometheus ./scripts/quickstart.sh

Going to localhost:19999/api/v1/rules?type=alert gives:

{"status":"success","data":{"groups":[{"name":"example","file":"data/rules.yml","rules":null,"interval":30,"evaluationTime":0,"lastEvaluation":"0001-01-01T00:00:00Z","partial_response_strategy":"WARN","partialResponseStrategy":"ABORT"}]}}

Three things seem off to me:

• rules is null even though the branch contains pkg/rules/rulespb: fix JSON marshaling for nil slices #2888 which supposedly fixes this problem
• Two fields partial_response_strategy and partialResponseStrategy that should show the same value but they are different in this case 🤔
• lastEvaluation is always set to 0001-01-01T00:00:00Z

[yeya24]

@GiedriusS Is this fixed by #2925 already? 😄

Updated: please ignore me, #2925 only fixes lastEvaluation is always set to 0001-01-01T00:00:00Z