Consider enforcing https://github.com/uber-go/goleak in all tests

[dmitryax]

This will require fixing all existing leaks first.

Suggested in #9100 (comment)

[crobert-1]

I've submitted a PR that adds goleak for all packages in which it's currently passing. Here's the complete list (that I'm aware of) of failing packages:

cmd/otelcorecol/ - Fixed in #9210
config/configgrpc/ - Fixed in #9217
config/configtls/ - Fixed in #9220
exporter/debugexporter/ - Fixed in #9210
exporter/exporterhelper/ - Fixed in #9215
exporter/exportertest/ - Fixed in #9210
exporter/internal/common/ - Fixed in #9210
exporter/loggingexporter/ - Fixed in #9210
exporter/otlpexporter/ - Fixed in #9210
exporter/otlphttpexporter/ - Fixed in #9222
internal/e2e/ - Fixed in #9223
internal/obsreportconfig/ - Fixed in #9210
obsreport/obsreporttest/ - Fixed in #9210
otelcol/ - Fixed in #9210
otelcol/otelcoltest/ - Fixed in #9210
processor/batchprocessor/ - Fixed in #9224
processor/memorylimiterprocessor/ - Fixed in #9210
processor/processorhelper/ - Fixed in #9210
receiver/otlpreceiver/internal/logs/ - Fixed in #9210
receiver/otlpreceiver/internal/metrics/ - Fixed in #9210
receiver/otlpreceiver/internal/trace/ - Fixed in #9210
receiver/otlpreceiver/ - Fixed in #9225
receiver/receiverhelper/ - Fixed in #9210
receiver/scraperhelper/ - Fixed in #9226
service/internal/proctelemetry/ - Fixed in #9227 - Reopened in #9230
service/ - Fixed in #9241

If it's helpful, I have a branch in my own fork that includes goleak for all packages, including the failures. It can be used to view failures if anyone is interested.

I'll update this comment to keep track of which packages still need goleak added.

[crobert-1]

It looks like a pretty common cause of goleak failures is the go.opencensus.io/stats/views package, specifically the start method. This is called by init(), so it's running in the background for any collector package that's importing the go.opencensus.io package, even indirectly.

goleak: Errors on successful test run: found unexpected goroutines:
[Goroutine 21 in state select, with go.opencensus.io/stats/view.(*worker).start on top of the stack:
go.opencensus.io/stats/view.(*worker).start(0xc0001a7b80)
	/Users/crobert/go/pkg/mod/go.opencensus.io@v0.24.0/stats/view/worker.go:292 +0x9f
created by go.opencensus.io/stats/view.init.0 in goroutine 1
	/Users/crobert/go/pkg/mod/go.opencensus.io@v0.24.0/stats/view/worker.go:34 +0x8d

I'm still investigating to better understand the impact and possible solution for this one cause of failures.

[yurishkuro]

We disabled check for opencensus worker in Jaeger because it starts via init() and not under control of the tests or any other code. Cf https://github.com/jaegertracing/jaeger/pull/5055/files#diff-13b40ba61afb4ff3b34affd949b1e9751f855f8c7f974e1896dc984aac2c212cR26

[yurishkuro]

There is a similar issue with glog, which we also ignored in goleak.