Handle errors in exporters

[jpkrohling]

This PR changes the batch processor to not ignore the errors returned by the exporters. It also adds more context to the messages, to make it clear which exporter failed.

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

[codecov]

Codecov Report

Merging #1259 into master will decrease coverage by 0.03%.
The diff coverage is 27.77%.

@@            Coverage Diff             @@
##           master    #1259      +/-   ##
==========================================
- Coverage   88.54%   88.50%   -0.04%     
==========================================
  Files         207      207              
  Lines       14945    14946       +1     
==========================================
- Hits        13233    13228       -5     
- Misses       1283     1286       +3     
- Partials      429      432       +3     

Impacted Files	Coverage Δ
exporter/opencensusexporter/opencensus.go	45.05% <0.00%> (ø)
exporter/otlpexporter/otlp.go	72.15% <33.33%> (ø)
exporter/zipkinexporter/zipkin.go	69.56% <33.33%> (ø)
processor/batchprocessor/batch_processor.go	95.77% <33.33%> (-1.39%)	⬇️
exporter/jaegerexporter/exporter.go	86.20% <50.00%> (ø)
translator/internaldata/resource_to_oc.go	86.04% <0.00%> (-4.66%)	⬇️

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[vikrambe]

@jpkrohling @bogdandrutu I tried updating PR 1251 with these changes, PR builds are failing with the below. On local this test passes but on Build pipeline this test fails. https://app.circleci.com/pipelines/github/open-telemetry/opentelemetry-
collector/1614/workflows/5dc38e8b-5092-4a1a-88ba-448a4aff1887/jobs/10923/steps. Can you take a look ?

TestApplication_GetExporters: testing.go:906: race detected during execution of test
--- FAIL: TestApplication_GetExporters (0.01s)
: testing.go:906: race detected during execution of test
FAIL
FAIL go.opentelemetry.io/collector/service 0.366s
FAIL

[jpkrohling]

@vikrambe are you sure it's caused by this PR here? This PR is basically just properly returning error objects to the callers. The batch processor is then logging them, but that doesn't seem to be the cause of the race condition (service/telemetry.go:110 vs. service/telemetry.go:116).

[vikrambe]

@jpkrohling My bad, it was due to a failing test in PR. Please ignore above comment. Thanks