Automatically set GOMAXPROCS

[cmacknz]

Describe the enhancement:
Automatically set GOMAXPROCS when beats are run in containers with a CFS quota set to minimize CPU throttling.

See elastic/apm-server#7967 and elastic/apm-server#8278 for more context. https://github.com/uber-go/automaxprocs can be used to easily add this feature.

Describe a specific use case for the enhancement or feature:
Setting GOMAXPROCS based on the configured CPU quota makes performance more predictable in containerized environments. Kubernetes deployments are particularly likely to experience problems from unoptimized GOMAXPROCS configurations.

[elasticmachine]

Pinging @elastic/elastic-agent-data-plane (Team:Elastic-Agent-Data-Plane)

[cmacknz]

Increasing the priority of this issue as I have been running into more cases of Beats and Elastic Agent performing poorly because of improperly tuned Kubernetes CPU quota configurations.

[joshdover]

@cmacknz In those SDHs that you mention, have customers been successful with setting GOMAXPROCS manually to solve their problem?

[cmacknz]

I haven't had this come up in a while, this is still a well known performance optimization though.