What does this PR do?

This PR adds support for macOS VMs in the KMT framework:

Use vmconfig templates to account for differences in OSs and paths
Fix configuration paths for macOS
Reorganization of certain files in tasks/kernel_matrix_testing to avoid import loops
Use libvirt socket path provided by OS configuration
Adapt some libvirt calls to macOS requirements
Provide initialisation code for VMs in macOS
Update KMT Readme
Fix kmt.ssh-config tasks for local VMs

Motivation

https://datadoghq.atlassian.net/browse/EBPF-421

Additional Notes

See additional developer documentation: https://datadoghq.atlassian.net/wiki/spaces/EBPFTEAM/pages/3478291163/Local+VM+support+for+KMT

Possible Drawbacks / Trade-offs

Describe how to test/QA your changes

Tested locally with different agent developers using macOS

Feb 16 '24 13:02 gjulianm

Bloop Bleep... Dogbot Here

Regression Detector Results

Run ID: 40a1a3ce-e469-40f9-b334-5b680e776fd8 Baseline: b4f0a172d309dc5b7689bc9674e0487e4fd0cf1b Comparison: ab3690a4ed796e279a125864edb7a939c99e2633

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.

Experiments ignored for regressions

Regressions in experiments with settings containing erratic: true are ignored.

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	file_to_blackhole	% cpu utilization	-0.74	[-7.06, +5.58]

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI
➖	basic_py_check	% cpu utilization	+1.33	[-1.21, +3.88]
➖	file_tree	memory utilization	+0.08	[-0.01, +0.18]
➖	process_agent_real_time_mode	memory utilization	+0.03	[-0.01, +0.06]
➖	uds_dogstatsd_to_api	ingress throughput	+0.00	[-0.00, +0.00]
➖	trace_agent_msgpack	ingress throughput	-0.00	[-0.00, +0.00]
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.00, +0.00]
➖	trace_agent_json	ingress throughput	-0.00	[-0.01, +0.01]
➖	idle	memory utilization	-0.02	[-0.05, +0.01]
➖	process_agent_standard_check_with_stats	memory utilization	-0.29	[-0.32, -0.26]
➖	process_agent_standard_check	memory utilization	-0.30	[-0.33, -0.27]
➖	tcp_syslog_to_blackhole	ingress throughput	-0.31	[-0.37, -0.26]
➖	otel_to_otel_logs	ingress throughput	-0.42	[-1.12, +0.28]
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-0.62	[-2.15, +0.90]
➖	file_to_blackhole	% cpu utilization	-0.74	[-7.06, +5.58]

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:

Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.
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.
Its configuration does not mark it "erratic".

Feb 16 '24 17:02 pr-commenter[bot]

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=30378511 --os-family=ubuntu

Mar 15 '24 14:03 pr-commenter[bot]