Make hostmetricsreceiver available in otel mode

[ycombinator]

Describe the enhancement:

Include the hostmetricsreceiver in the OTel Collector components we bundle with Elastic Agent.

Describe a specific use case for the enhancement or feature:

Users of Elastic Agent in OTel mode (elastic-agent otel ...) would like to be able to use the hostmetricsreceiver in their OTel Collector pipeline configurations.

What is the definition of done?

• A test that runs Elastic Agent in OTel mode (elastic-agent otel ...) includes the hostmetricsreceiver in it's test OTel Collector configuration and the test passes.

[ycombinator]

Note that an attempt was already made to try and bundle the hostmetricsreceiver with Elastic Agent in #4706 but CI failed Serverless tests 🤷 on the following error:

>>> (windows-amd64-2022-fleet) Test output (sudo) (stdout): Error: error starting service: failed to start service (Elastic Agent): The service did not respond to the start or control request in a timely fashion.

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[ycombinator]

Please remember to backport this issue's PR to the 8.14 branch.

[jlind23]

Please remember to backport this issue's PR to the 8.14 branch.

@ycombinator @andrzej-stencel this is because it has to be available for 8.14.2 right?

[ycombinator]

@ycombinator @andrzej-stencel this is because it has to be available for 8.14.2 right?

That's correct. We want the Elasticsearch exporter to be able to export metrics produced by the hostmetricsreceiver in ECS format for 8.14.2. So, as a dependency, we will also want the hostmetricsreceiver itself to be in 8.14.2 as well.

[ycombinator]

@cmacknz This issue came up for discussion in today's OTel Weekly sync meeting, specifically the Windows failures we were seeing the last time we tried to include the hostmetricsreceiver in Elastic Agent. @strawgate mentioned you suggested some way to exclude this receiver only on Windows. I was curious how we'd go about this, considering we'd still need the require in go.mod and the import in https://github.com/elastic/elastic-agent/blob/main/internal/pkg/otel/components.go. Were you thinking something as simple as adding a if runtime.GOOS == "windows" conditional around

elastic-agent/internal/pkg/otel/components.go

Lines 41 to 44 in d2d88ca

	factories.Receivers, err = receiver.MakeFactoryMap(
	otlpreceiver.NewFactory(),
	filelogreceiver.NewFactory(),
	)

or something else?

[cmacknz]

I didn't have any specific way of doing this in mind, but a conditional on runtime.GOOS would work.

I don't think we've spent much time actually investigating why it fails, so I'd prefer we put a day into that first, and only make it conditional if we can't figure out what is wrong.