[NPM-3663] Include BTF availability in agent flare

[pimlu]

What does this PR do?

This PR adds information about where we are loading BTF information from to the agent flare.

Motivation

This can tell us why CO-RE is running into issues, and particularly with our bundled BTF files, if we are correctly identifying the distro + kernel.

Describe how to test/QA your changes

Install the agent from the CI build packages, configure the system-probe to run and run an agent flare. Expect to see system-probe/ebpf_btf_loader.log with this information. Example when cilium loads the BTF data:

loader: kernel
source file: <unknown, internal to cilium ebpf>

If the data comes from a user configured BTF file or our bundled BTF files, the source file: field will contain the path to that BTF file.

Possible Drawbacks / Trade-offs

Additional Notes

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Run ID: 0e175603-bcfa-4103-a8fc-6504b6886feb Metrics dashboard Target profiles

Baseline: 2f80c77
Comparison: cf5c3b3

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	trials	links
➖	idle	memory utilization	+0.13	[+0.08, +0.17]	1	Logs bounds checks dashboard
➖	file_to_blackhole_500ms_latency	egress throughput	+0.11	[-0.14, +0.35]	1	Logs
➖	quality_gate_idle	memory utilization	+0.06	[+0.02, +0.11]	1	Logs bounds checks dashboard
➖	quality_gate_idle_all_features	memory utilization	+0.06	[-0.07, +0.18]	1	Logs bounds checks dashboard
➖	otel_to_otel_logs	ingress throughput	+0.03	[-0.77, +0.84]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	+0.02	[-0.21, +0.24]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.02	[-0.33, +0.36]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	+0.00	[-0.18, +0.18]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.09, +0.09]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-0.04	[-0.53, +0.44]	1	Logs
➖	basic_py_check	% cpu utilization	-0.09	[-2.82, +2.65]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-0.11	[-0.83, +0.61]	1	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-0.45	[-0.50, -0.40]	1	Logs
➖	pycheck_lots_of_tags	% cpu utilization	-0.47	[-2.98, +2.04]	1	Logs
➖	idle_all_features	memory utilization	-1.37	[-1.50, -1.25]	1	Logs bounds checks dashboard
➖	file_tree	memory utilization	-2.56	[-2.70, -2.41]	1	Logs

Bounds Checks

perf	experiment	bounds_check_name	replicates_passed
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_300ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	idle	memory_usage	10/10
✅	idle_all_features	memory_usage	10/10
✅	quality_gate_idle	memory_usage	10/10
✅	quality_gate_idle_all_features	memory_usage	10/10

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".

[agent-platform-auto-pr]

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=47989284 --os-family=ubuntu

Note: This applies to commit cf5c3b3

[akarpz]

needs a release note (I think this is a good example of a time to include one)

[pimlu]

/merge

[dd-devflow]

🚂 MergeQueue: pull request added to the queue

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Use /merge -c to cancel this operation!

[pimlu]

/remove

[dd-devflow]

🚂 Devflow: /remove

[dd-devflow]

⚠️ MergeQueue: This merge request build was cancelled

This merge request build was cancelled

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[pimlu]

/merge

[dd-devflow]

🚂 MergeQueue: pull request added to the queue

The median merge time in main is 23m.

Use /merge -c to cancel this operation!