add linux compatibility for diagnose port-conflict

[mwdd146980]

What does this PR do?

Add linux compatibility for the diagnose port conflict suite. This builds on PR#25209.

Motivation

Making this feature available for Linux is make it much more useful since our customers are much more likely to be on Linux compared to MacOS.

Possible Drawbacks / Trade-offs

This PR will make this feature available for MacOS and Linux. Windows will come after.

Describe how to test/QA your changes

Check that the diagnose suite works properly for Linux and Darwin:

• when the agent isn't running and there is no port issue
• when the agent is running and there is no port issue (the agent is detected as being the agent, so no issue is raised)
• when some port is used by another process, it is reported
  You can use netcat to bind to a port:

netcat -nvlp 6062

Reviewer's Checklist

• If known, an appropriate milestone has been selected; otherwise the Triage milestone is set.
• Use the major_change label if your change either has a major impact on the code base, is impacting multiple teams or is changing important well-established internals of the Agent. This label will be use during QA to make sure each team pay extra attention to the changed behavior. For any customer facing change use a releasenote.
• A release note has been added or the changelog/no-changelog label has been applied.
• Changed code has automated tests for its functionality.
• Adequate QA/testing plan information is provided if the qa/skip-qa label is not applied.
• At least one team/.. label has been applied, indicating the team(s) that should QA this change.
• If applicable, docs team has been notified or an issue has been opened on the documentation repo.
• If applicable, the need-change/operator and need-change/helm labels have been applied.
• If applicable, the k8s/<min-version> label, indicating the lowest Kubernetes version compatible with this feature.
• If applicable, the config template has been updated.

[bits-bot]

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[cit-pr-commenter]

Go Package Import Differences

Baseline: ae0274b
Comparison: ec72950

binary	os	arch	change
agent	linux	amd64	+1, -0 +go4.org/mem
agent	linux	arm64	+1, -0 +go4.org/mem
iot-agent	linux	amd64	+2, -0 +go4.org/mem +hash/maphash
iot-agent	linux	arm64	+2, -0 +go4.org/mem +hash/maphash
heroku-agent	linux	amd64	+2, -0 +go4.org/mem +hash/maphash
cluster-agent	linux	amd64	+1, -0 +go4.org/mem
cluster-agent	linux	arm64	+1, -0 +go4.org/mem
cluster-agent-cloudfoundry	linux	amd64	+2, -0 +go4.org/mem +hash/maphash
cluster-agent-cloudfoundry	linux	arm64	+2, -0 +go4.org/mem +hash/maphash
security-agent	linux	amd64	+2, -0 +go4.org/mem +hash/maphash
security-agent	linux	arm64	+2, -0 +go4.org/mem +hash/maphash

[pr-commenter]

Test changes on VM

Use this command from test-infra-definitions to manually test this PR changes on a VM:

inv create-vm --pipeline-id=34399987 --os-family=ubuntu

[pr-commenter]

Regression Detector

Regression Detector Results

Run ID: 9d48eb8f-caf8-40fb-9e2e-f1718eb96d65
Baseline: ae0274b
Comparison: ec72950

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

No significant changes in experiment optimization goals

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

There were no significant changes in experiment optimization goals at this confidence level and effect size tolerance.

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+3.36	[+0.53, +6.19]
➖	file_tree	memory utilization	+1.58	[+1.49, +1.67]
➖	pycheck_1000_100byte_tags	% cpu utilization	+0.80	[-3.75, +5.34]
➖	idle	memory utilization	+0.18	[+0.15, +0.21]
➖	basic_py_check	% cpu utilization	+0.18	[-2.37, +2.73]
➖	otel_to_otel_logs	ingress throughput	+0.17	[-0.21, +0.54]
➖	uds_dogstatsd_to_api	ingress throughput	+0.01	[-0.19, +0.21]
➖	trace_agent_json	ingress throughput	+0.00	[-0.01, +0.01]
➖	trace_agent_msgpack	ingress throughput	-0.00	[-0.00, +0.00]
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.03	[-0.07, +0.01]
➖	tcp_syslog_to_blackhole	ingress throughput	-10.53	[-30.27, +9.20]

Explanation

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".