azuremonitor: mark spanToEnvelope err as permanent (#500)

The conversion from span to envelope is deterministic. It will always
result in the same error for the same input span. This type of error
should be marked as permanent, so that processors don't attempt to
retry it.

exporter/azuremonitorexporter/traceexporter.go

@@ -18,6 +18,7 @@ import (
  "context"
 
  "go.opentelemetry.io/collector/component"
+ "go.opentelemetry.io/collector/consumer/consumererror"
  "go.opentelemetry.io/collector/consumer/pdata"
  "go.opentelemetry.io/collector/exporter/exporterhelper"
  "go.uber.org/zap"
@@ -43,7 +44,7 @@ func (v *traceVisitor) visit(
  envelope, err := spanToEnvelope(resource, instrumentationLibrary, span, v.exporter.logger)
  if err != nil {
  // record the error and short-circuit
- v.err = err
+ v.err = consumererror.Permanent(err)
  return false
  }
 

exporter/azuremonitorexporter/traceexporter_test.go

@@ -19,6 +19,7 @@ import (
 
  "github.com/stretchr/testify/assert"
  mock "github.com/stretchr/testify/mock"
+ "go.opentelemetry.io/collector/consumer/consumererror"
  "go.opentelemetry.io/collector/consumer/pdata"
  "go.uber.org/zap"
  "golang.org/x/net/context"
@@ -99,6 +100,7 @@ func TestExporterTraceDataCallbackSingleSpanNoEnvelope(t *testing.T) {
 
  droppedSpans, err := exporter.onTraceData(context.Background(), traces)
  assert.NotNil(t, err)
+ assert.True(t, consumererror.IsPermanent(err), "error should be permanent")
  assert.Equal(t, 1, droppedSpans)
 
  mockTransportChannel.AssertNumberOfCalls(t, "Send", 0)