auto_instrumentation: disable DOTNET_PROFILER by default

[stanistan]

What does this PR do?

This PR disables injection of the DOTNET profiler by default with the auto instrumentation webhook by gating it by a config flag.

https://datadoghq.atlassian.net/browse/APMON-626

Motivation

While we wait for updates to the dotnet library package to address some issues, we are disabling profiling by default.

This ensures consistent features across host and kubernets auto instrumentation (host does not do profiling by default).

This also adds a config flag for users who want to enable the option.

Describe how to test/QA your changes

Tests were added to the injection code to verify that the profiling env vars would not be injected by default, and old tests updated to reflect that this config needs to be enabled for those environment variables to be injected.

[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=38470197 --os-family=ubuntu

Note: This applies to commit 9ee43505

[pr-commenter[bot]]

Regression Detector

Regression Detector Results

Run ID: 65bc9868-8fa6-4147-8c8f-dc5701b68501 Metrics dashboard Target profiles

Baseline: f747174e7d4a547277a046aedb161cc1651a915e Comparison: 9ee4350531458ea0799ddb6f9348047b650713db

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	links
➖	basic_py_check	% cpu utilization	+1.94	[-0.73, +4.60]	Logs
➖	idle	memory utilization	+0.62	[+0.58, +0.65]	Logs
➖	otel_to_otel_logs	ingress throughput	+0.41	[-0.40, +1.22]	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.00, +0.00]	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	Logs
➖	pycheck_1000_100byte_tags	% cpu utilization	-0.14	[-4.89, +4.61]	Logs
➖	file_tree	memory utilization	-0.45	[-0.50, -0.39]	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	-0.54	[-1.43, +0.34]	Logs
➖	tcp_syslog_to_blackhole	ingress throughput	-5.48	[-18.01, +7.05]	Logs

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[bot]]

[Fast Unit Tests Report]

On pipeline 38470197 (CI Visibility). The following jobs did not run any unit tests:

Jobs:

• tests_flavor_dogstatsd_deb-x64
• tests_flavor_heroku_deb-x64
• tests_flavor_iot_deb-x64

If you modified Go files and expected unit tests to run in these jobs, please double check the job logs. If you think tests should have been executed reach out to #agent-devx-help

[stanistan]

/merge

[stanistan]

/merge -c

[dd-devflow[bot]]

:steam_locomotive: MergeQueue: waiting for PR to be ready

This merge request is not mergeable yet, because of pending checks/missing approvals. It will be added to the queue as soon as checks pass and/or get approvals. Note: if you pushed new commits since the last approval, you may need additional approval. You can remove it from the waiting list with /remove command.

Use /merge -c to cancel this operation!

[dd-devflow[bot]]

:steam_locomotive: MergeQueue: waiting for PR to be ready

This merge request is not mergeable yet, because of pending checks/missing approvals. It will be added to the queue as soon as checks pass and/or get approvals. Note: if you pushed new commits since the last approval, you may need additional approval. You can remove it from the waiting list with /remove command.

Use /merge -c to cancel this operation!

[dd-devflow[bot]]

:warning: MergeQueue: This merge request was unqueued

This merge request was unqueued

If you need support, contact us on Slack #devflow!

[stanistan]

/merge

[dd-devflow[bot]]

:steam_locomotive: MergeQueue: pull request added to the queue

The median merge time in main is 26m.

Use /merge -c to cancel this operation!