Data Race in otelhttp instrumentation

[rosstimothy]

Description

After upgrading to otelhttp v0.48.0 we started seeing the following race in our tests:

WARNING: DATA RACE
Write at 0x00c003b26498 by goroutine 8036:
  go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.(*bodyWrapper).Read()
      /go/pkg/mod/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp@v0.48.0/wrap.go:40 +0x9c
  io.discard.ReadFrom()
      /opt/go/src/io/io.go:666 +0x91
  io.(*discard).ReadFrom()
      <autogenerated>:1 +0x4c
  io.copyBuffer()
      /opt/go/src/io/io.go:415 +0x22e
  io.CopyBuffer()
      /opt/go/src/io/io.go:402 +0x8f
  net/http.(*transferWriter).doBodyCopy()
      /opt/go/src/net/http/transfer.go:416 +0x144
  net/http.(*transferWriter).writeBody()
      /opt/go/src/net/http/transfer.go:376 +0x7ac
  net/http.(*Request).write()
      /opt/go/src/net/http/request.go:755 +0x1413
  net/http.(*persistConn).writeLoop()
      /opt/go/src/net/http/transport.go:2446 +0x379
  net/http.(*Transport).dialConn.gowrap3()
      /opt/go/src/net/http/transport.go:1799 +0x33

Previous read at 0x00c003b26498 by goroutine 8053:
  go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp.(*Transport).RoundTrip()
      /go/pkg/mod/go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp@v0.48.0/transport.go:185 +0xfa4
  github.com/gravitational/teleport/api/observability/tracing/http.(*roundTripWrapper).RoundTrip()
      <autogenerated>:1 +0x51
  net/http.send()
      /opt/go/src/net/http/client.go:259 +0x9a6
  net/http.(*Client).send()
      /opt/go/src/net/http/client.go:180 +0x14e
  net/http.(*Client).do()
      /opt/go/src/net/http/client.go:724 +0x11c8
  net/http.(*Client).Do()
      /opt/go/src/net/http/client.go:590 +0x31d
==================

Environment

• OS: [e.g. iOS] All
• Architecture: [e.g. x86, i386] All
• Go Version: [e.g. 1.15] All
• otelhttp version: v0.48.0

[rosstimothy]

This seems to originate from #5080

[MrAlias]

This seems to originate from #5080

Your description states you are testing against v0.48.0. #5080 has not been released yet, what makes you think that is causing your error?

[MrAlias]

Is this a duplicate of #4895?

[dmathieu]

Closing as duplicate of #4895.