test(usm): fix flakiness in resolver periodic-update tests

[chouquette]

What does this PR do?

Waits for the resolver's background periodic update to actually complete before asserting on it in pkg/process/net/resolver tests, instead of relying on a fixed 1ms sleep.

Motivation

TestLocalResolverPeriodicUpdates and two other tests with the same pattern raced against the background goroutine processing the mock clock tick, causing intermittent failures under CPU contention. See https://gitlab.ddbuild.io/DataDog/datadog-agent/-/jobs/2015504947

Describe how you validated your changes

• dda inv -- -e test --targets=./pkg/process/net/resolver/..., with and without --race: all tests pass.

Additional Notes

[github-actions]

AI review by Codex (OpenAI) - workflow run

The patch is incorrect because it replaces one timing-dependent wait with another, leaving the tests vulnerable to CI contention.

[github-actions]

Eventually still depends on wall-clock polling and an arbitrary 2-second deadline, so these tests can remain flaky under sufficient contention. Synchronize with the mocked GetContainers call (for example, signal a channel from DoAndReturn) and wait for that completion instead. The same issue applies to the other added Eventually calls.

[chouquette]

My understanding is that relying on a channel here would need to also change the code being tested, which I don't want to do.

I'll let the reviewers comment further since I don't know this code enough to make the call IMHO

[datadog-datadog-us1-prod]

🎯 Code Coverage (details)
• Patch Coverage: 100.00%
• Overall Coverage: 56.99% (+1.72%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: f7e489c | Docs | View more details | Give us feedback!}

[github-actions]

AI review by Codex (OpenAI) - workflow run

Patch is incorrect: it replaces one timing-dependent wait with another, so the tests can still flake under sufficiently slow CI scheduling.

[github-actions]

The wall-clock-based Eventually polling remains timing-dependent and can still fail when the resolver goroutine is delayed beyond two seconds; the same pattern is added in four places. Please synchronize deterministically with the mocked GetContainers call/update completion (and use a fatal assertion if later checks depend on it) instead of imposing a real-time deadline.

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor 7941fa9a:

Results for datadog-agent_7.85.0~devel.git.10.f7e489c.pipeline.135467376-1_amd64.deb:

No change detected

Results for datadog-iot-agent_7.85.0~devel.git.10.f7e489c.pipeline.135467376-1_amd64.deb:

No change detected

[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor 7941fa9
📊 Static Quality Gates Dashboard
🔗 SQG Job

32 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64	768.464 MiB
✅	agent_deb_amd64_fips	715.052 MiB
✅	agent_heroku_amd64	316.124 MiB
✅	agent_rpm_amd64	768.448 MiB
✅	agent_rpm_amd64_fips	715.036 MiB
✅	agent_rpm_arm64	740.392 MiB
✅	agent_rpm_arm64_fips	691.525 MiB
✅	agent_suse_amd64	768.448 MiB
✅	agent_suse_amd64_fips	715.036 MiB
✅	agent_suse_arm64	740.392 MiB
✅	agent_suse_arm64_fips	691.525 MiB
✅	docker_agent_amd64	827.427 MiB
✅	docker_agent_arm64	824.427 MiB
✅	docker_agent_jmx_amd64	1018.340 MiB
✅	docker_agent_jmx_arm64	1004.120 MiB
✅	docker_cluster_agent_amd64	212.687 MiB
✅	docker_cluster_agent_arm64	225.718 MiB
✅	docker_cws_instrumentation_amd64	7.439 MiB
✅	docker_cws_instrumentation_arm64	6.877 MiB
✅	docker_dogstatsd_amd64	39.557 MiB
✅	docker_dogstatsd_arm64	37.686 MiB
✅	docker_host_profiler_amd64	307.574 MiB
✅	docker_host_profiler_arm64	318.791 MiB
✅	dogstatsd_deb_amd64	30.303 MiB
✅	dogstatsd_deb_arm64	28.315 MiB
✅	dogstatsd_rpm_amd64	30.303 MiB
✅	dogstatsd_suse_amd64	30.303 MiB
✅	iot_agent_deb_amd64	46.651 MiB
✅	iot_agent_deb_arm64	43.280 MiB
✅	iot_agent_deb_armhf	44.097 MiB
✅	iot_agent_rpm_amd64	46.651 MiB
✅	iot_agent_suse_amd64	46.650 MiB

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Job ID: c560e429-8aa0-44cb-bcd0-603b135662cc

Baseline: 7941fa9
Comparison: f7e489c
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	quality_gate_metrics_logs	memory utilization	+0.94	[+0.71, +1.17]	1	Logs bounds checks dashboard
➖	quality_gate_private_action_runner	memory utilization	+0.35	[+0.22, +0.47]	1	Logs bounds checks dashboard
➖	dsd_uds_10mb_3k_timestamped_contexts_memory	memory utilization	+0.29	[+0.07, +0.51]	1	Logs
➖	quality_gate_security_idle	memory utilization	+0.27	[+0.24, +0.31]	1	Logs bounds checks dashboard
➖	quality_gate_idle	memory utilization	+0.18	[+0.14, +0.23]	1	Logs bounds checks dashboard
➖	quality_gate_security_no_fs_load	memory utilization	+0.12	[+0.05, +0.20]	1	Logs bounds checks dashboard
➖	dsd_uds_10mb_3k_timestamped_contexts_cpu	% cpu utilization	+0.07	[-0.21, +0.36]	1	Logs
➖	quality_gate_security_mean_fs_load	memory utilization	-0.04	[-0.08, -0.01]	1	Logs bounds checks dashboard
➖	quality_gate_idle_all_features	memory utilization	-0.11	[-0.16, -0.05]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.71	[-1.58, +0.15]	1	Logs bounds checks dashboard

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	observed_value	links
✅	quality_gate_idle	intake_connections	10/10	4 ≤ 5	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	176.38MiB ≤ 179MiB	bounds checks dashboard
✅	quality_gate_idle	total_bytes_received	10/10	748.39KiB ≤ 819.20KiB	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	2 ≤ 5	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	470.74MiB ≤ 537MiB	bounds checks dashboard
✅	quality_gate_idle_all_features	total_bytes_received	10/10	1.12MiB ≤ 1.25MiB	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	19 ≤ 40	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	212.98MiB ≤ 228MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_logs	total_bytes_received	10/10	263.52MiB ≤ 292MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	377.42 ≤ 2000	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	19 ≤ 40	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	430.02MiB ≤ 455MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_metrics_logs	total_bytes_received	10/10	0.94GiB ≤ 1.04GiB	bounds checks dashboard
✅	quality_gate_private_action_runner	memory_usage	10/10	72MiB ≤ 75MiB	bounds checks dashboard
✅	quality_gate_security_idle	cpu_usage	10/10	30.19 ≤ 100	bounds checks dashboard
✅	quality_gate_security_idle	memory_usage	10/10	328.53MiB ≤ 355MiB	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	cpu_usage	10/10	66.18 ≤ 200	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	memory_usage	10/10	307.94MiB ≤ 335MiB	bounds checks dashboard
✅	quality_gate_security_no_fs_load	cpu_usage	10/10	23.97 ≤ 100	bounds checks dashboard
✅	quality_gate_security_no_fs_load	memory_usage	10/10	314.91MiB ≤ 345MiB	bounds checks dashboard

Explanation

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

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

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".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_security_no_fs_load, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_no_fs_load, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_private_action_runner, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_security_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_idle, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_mean_fs_load, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_mean_fs_load, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 10/10 replicas passed. Gate passed.