[exporter/loki] Allow nested attribute to be promoted to label

[jpkrohling]

Adds the possibility of looking up nested attributes using dot notation, in case no attribute matching the name exists.

Fixes #16475

Signed-off-by: Juraci Paixão Kröhling juraci@kroehling.de

[runforesight]

Foresight Summary

    
Major Impacts

TestConsumeLogsUnexpectedExporterType ❌ failed 2 times in 4 runs (50% fail rate).

TestConsumeTracesUnexpectedExporterType ❌ failed 2 times in 4 runs (50% fail rate).

build-and-test-windows duration(5 seconds) has decreased 40 minutes 50 seconds compared to main branch avg(40 minutes 55 seconds).

View More Details

⭕  build-and-test-windows workflow has finished in 5 seconds (40 minutes 50 seconds less than main branch avg.) and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
windows-unittest-matrix	-     🔗	N/A	See Details
windows-unittest	-     🔗	N/A	See Details

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✅  check-links workflow has finished in 39 seconds (2 minutes 38 seconds less than main branch avg.) and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
changed files	-     🔗	N/A	See Details
check-links	-     🔗	N/A	See Details

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✅  tracegen workflow has finished in 1 minute 8 seconds (2 minutes 31 seconds less than main branch avg.) and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
build-dev	-     🔗	N/A	See Details
publish-latest	-     🔗	N/A	See Details
publish-stable	-     🔗	N/A	See Details

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✅  changelog workflow has finished in 2 minutes 15 seconds (5 minutes 11 seconds less than main branch avg.) and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
changelog	-     🔗	N/A	See Details

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❌  build-and-test workflow has finished in 28 minutes 48 seconds (31 minutes 26 seconds less than main branch avg.) and finished at 15th Dec, 2022. 1 job failed. There are 4 test failures.

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Job	Failed Steps	Tests
unittest-matrix (1.19, internal)	-     🔗	✅ 592  ❌ 0  ⏭ 0    🔗	See Details
correctness-metrics	-     🔗	✅ 2  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, internal)	-     🔗	✅ 592  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.19, processor)	-     🔗	✅ 1441  ❌ 0  ⏭ 0    🔗	See Details
correctness-traces	-     🔗	✅ 17  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.19, extension)	-     🔗	✅ 528  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, processor)	-     🔗	✅ 1441  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, extension)	-     🔗	✅ 528  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.19, receiver-0)	-     🔗	✅ 2535  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, receiver-0)	-     🔗	✅ 2535  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, other)	-     🔗	✅ 4365  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.19, exporter)	-     🔗	✅ 2237  ❌ 2  ⏭ 0    🔗	See Details
unittest-matrix (1.19, other)	-     🔗	✅ 4365  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, receiver-1)	-     🔗	✅ 1854  ❌ 0  ⏭ 0    🔗	See Details
unittest-matrix (1.18, exporter)	-     🔗	✅ 2237  ❌ 2  ⏭ 0    🔗	See Details
unittest-matrix (1.19, receiver-1)	-     🔗	✅ 1854  ❌ 0  ⏭ 0    🔗	See Details
integration-tests	-     🔗	✅ 53  ❌ 0  ⏭ 0    🔗	See Details
setup-environment	-     🔗	N/A	See Details
check-collector-module-version	-     🔗	N/A	See Details
lint-matrix (receiver-0)	-     🔗	N/A	See Details
lint-matrix (receiver-1)	-     🔗	N/A	See Details
lint-matrix (processor)	-     🔗	N/A	See Details
lint-matrix (exporter)	-     🔗	N/A	See Details
lint-matrix (extension)	-     🔗	N/A	See Details
lint-matrix (internal)	-     🔗	N/A	See Details
lint-matrix (other)	-     🔗	N/A	See Details
checks	-     🔗	N/A	See Details
check-codeowners	-     🔗	N/A	See Details
build-examples	-     🔗	N/A	See Details
unittest (1.19)	-     🔗	N/A	See Details
unittest (1.18)	-     🔗	N/A	See Details
lint	-     🔗	N/A	See Details
cross-compile (darwin, amd64)	-     🔗	N/A	See Details
cross-compile (darwin, arm64)	-     🔗	N/A	See Details
cross-compile (linux, 386)	-     🔗	N/A	See Details
cross-compile (linux, amd64)	-     🔗	N/A	See Details
cross-compile (linux, arm)	-     🔗	N/A	See Details
cross-compile (linux, arm64)	-     🔗	N/A	See Details
cross-compile (linux, ppc64le)	-     🔗	N/A	See Details
cross-compile (windows, 386)	Build Collector     🔗	N/A	See Details
cross-compile (windows, amd64)	-     🔗	N/A	See Details
windows-msi	-     🔗	N/A	See Details
build-package	-     🔗	N/A	See Details
publish-dev	-     🔗	N/A	See Details
publish-check	-     🔗	N/A	See Details
publish-stable	-     🔗	N/A	See Details

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✅  prometheus-compliance-tests workflow has finished in 9 minutes 58 seconds and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
prometheus-compliance-tests	-     🔗	✅ 21  ❌ 0  ⏭ 0    🔗	See Details

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✅  load-tests workflow has finished in 23 minutes 46 seconds (⚠️ 6 minutes 51 seconds more than main branch avg.) and finished at 15th Dec, 2022.

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Job	Failed Steps	Tests
loadtest (TestIdleMode)	-     🔗	✅ 1  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestTraceAttributesProcessor)	-     🔗	✅ 3  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestMetric10kDPS|TestMetricsFromFile)	-     🔗	✅ 6  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestTraceBallast1kSPSWithAttrs|TestTraceBallast1kSPSAddAttrs)	-     🔗	✅ 10  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestMetricResourceProcessor|TestTrace10kSPS)	-     🔗	✅ 12  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestBallastMemory|TestLog10kDPS)	-     🔗	✅ 19  ❌ 0  ⏭ 0    🔗	See Details
loadtest (TestTraceNoBackend10kSPS|TestTrace1kSPSWithAttrs)	-     🔗	✅ 8  ❌ 0  ⏭ 0    🔗	See Details
setup-environment	-     🔗	N/A	See Details

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[evan-bradley]

Looks good to me.

[evan-bradley]

Requesting review from code owners: @gramidt @gouthamve @kovrus @mar4uk.

[kovrus]

lgtm