Stop the agent from attempting to reach a Kubelet when running as a cluster checks runner

[mrdoggopat]

What does this PR do?

Stops the Agent from attempting to reach a local Kubelet when running as a Cluster Checks Runner (CCR).

Cluster Checks Runners are Deployment replicas, not DaemonSets so they aren't scheduled per-node, so a CCR pod never has a locally-reachable Kubelet. Despite that, several independent code paths unconditionally called into kubelet.GetKubeUtil() / GetKubeUtilWithRetrier(), each of which restarts the same HTTPS→HTTP fallback probe and keeps its exponential-backoff retrier alive. This PR adds a helper.IsCLCRunner(...) guard to each of the six call sites found to trigger this:

1. pkg/util/kubernetes/cloudprovider/cloudprovider.go - GetName(), used to populate the kube_distribution host tag (host-tags refresh cycle, ~30 min).
2. pkg/util/kubernetes/clustername/clustername.go - getClusterName()'s unconditional node-label lookup via hostinfo.NewNodeInfo() (same ~30 min cycle). Config-provided or cloud-provider-discovered cluster names are unaffected; only the node-label auto-discovery/override step is skipped on CCR.
3. comp/core/workloadmeta/collectors/internal/kubelet/kubelet.go and .../kubemetadata/kubemetadata.go — Start() now returns errors.NewDisabled(...) on CCR instead of letting workloadmeta's own candidate-retry loop (1s → 30s exponential backoff, no max elapsed time) retry it forever.
4. comp/metadata/host/impl/hosttags/tags.go - the "kubernetes" host-tags provider is no longer registered at all on CCR (same ~30 min refresh cycle).
5. pkg/util/containers/metrics/kubelet/collector.go - the kubelet container-metrics collector's constructor now returns provider.ErrPermaFail on CCR, instead of getting retried forever by the metrics-provider registry's independent 2-second discovery ticker.
6. pkg/util/cloudproviders/cloudproviders.go - GetHostAliases()'s kubelet and kubernetes host-alias detectors, which route through the shared kubelet client singleton (host-metadata refresh cycle, ~30 min, plus agent startup). Both detectors are now skipped entirely on CCR instead of hitting the kubelet retrier's exponential backoff on every refresh.

Each of the six guards is independent as they sit on genuinely separate callers of the shared Kubelet retrier singleton, triggered by different subsystems and cadences (host-tags refresh, workloadmeta collector startup, and the metrics registry's ticker). Removing any single one reintroduces the warning from exactly that call path.

There is no change in behavior for the node Agent or Cluster Agent. All guards are scoped to helper.IsCLCRunner(...).

Motivation

CONS-8502

Historically, the Cluster Checks Runner has always tried to reach a local Kubelet on startup and on periodic refreshes, even though it's fundamentally incapable of reaching one (it's a Deployment replica, not a per-node DaemonSet). This was previously a Debug-level log, so it went unnoticed. PR #51447 raised the Kubelet HTTPS-fallback log from Debug to Warn (first released in 7.81.0), which turned this long-standing, harmless-but-pointless probing into a recurring WARN.

Describe how you validated your changes

• Built a test image and deployed it as a real CCR pod in a cluster to reproduce and validate.
• Added unit tests for the CLC-runner-guarded behavior in each touched package.

[datadog-prod-us1-6]

🎯 Code Coverage (details)
• Patch Coverage: 66.67%
• Overall Coverage: 52.40% (+0.04%)

_{This comment will be updated automatically if new data arrives.
🔗 Commit SHA: 4cb48ce | Docs | Datadog PR Page | Give us feedback!}

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor afcc03c4:

Results for datadog-agent_7.84.0~devel.git.205.4cb48ce.pipeline.131078063-1_amd64.deb:

No change detected

Results for datadog-iot-agent_7.84.0~devel.git.205.4cb48ce.pipeline.131078063-1_amd64.deb:

No change detected

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Job ID: 5639d466-dbcc-40c4-8b2f-f0b5cfb5457f

Baseline: afcc03c
Comparison: 4cb48ce
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_logs	% cpu utilization	+3.18	[+2.28, +4.09]	1	Logs bounds checks dashboard
➖	quality_gate_metrics_logs	memory utilization	+1.08	[+0.83, +1.33]	1	Logs bounds checks dashboard
➖	quality_gate_idle	memory utilization	+0.41	[+0.29, +0.53]	1	Logs bounds checks dashboard
➖	quality_gate_idle_all_features	memory utilization	+0.07	[+0.02, +0.11]	1	Logs bounds checks dashboard
➖	quality_gate_security_mean_fs_load	memory utilization	-0.27	[-0.35, -0.20]	1	Logs bounds checks dashboard
➖	quality_gate_security_idle	memory utilization	-0.30	[-0.40, -0.19]	1	Logs bounds checks dashboard
➖	quality_gate_private_action_runner	memory utilization	-0.30	[-0.42, -0.19]	1	Logs bounds checks dashboard
➖	quality_gate_security_no_fs_load	memory utilization	-0.42	[-0.57, -0.28]	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 = 4	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	172.59MiB ≤ 178MiB	bounds checks dashboard
✅	quality_gate_idle	total_bytes_received	10/10	741.94KiB ≤ 819.20KiB	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	4 = 4	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	528.13MiB ≤ 538MiB	bounds checks dashboard
✅	quality_gate_idle_all_features	total_bytes_received	10/10	1.13MiB ≤ 1.25MiB	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	17 ≤ 40	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	205.62MiB ≤ 229MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_logs	total_bytes_received	10/10	264.22MiB ≤ 292MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	366.49 ≤ 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	426.05MiB ≤ 439MiB	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	71.91MiB ≤ 76MiB	bounds checks dashboard
✅	quality_gate_security_idle	cpu_usage	10/10	27.17 ≤ 100	bounds checks dashboard
✅	quality_gate_security_idle	memory_usage	10/10	326.71MiB ≤ 335MiB	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	cpu_usage	10/10	62.15 ≤ 200	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	memory_usage	10/10	301.43MiB ≤ 314MiB	bounds checks dashboard
✅	quality_gate_security_no_fs_load	cpu_usage	10/10	20.47 ≤ 100	bounds checks dashboard
✅	quality_gate_security_no_fs_load	memory_usage	10/10	309.54MiB ≤ 343MiB	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_idle, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle, bounds check intake_connections: 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 memory_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 total_bytes_received: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_security_mean_fs_load, 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_no_fs_load, bounds check cpu_usage: 10/10 replicas passed. Gate passed.
• quality_gate_security_no_fs_load, bounds check memory_usage: 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 intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check missed_bytes: 10/10 replicas passed. Gate passed.

[chatgpt-codex-connector]

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[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor afcc03c
📊 Static Quality Gates Dashboard
🔗 SQG Job

Successful checks

Info

	Quality gate	Change	Size (prev → curr → max)
✅	agent_deb_amd64	+12.5 KiB (0.00% increase, -0.25% of buffer)	759.616 → 759.628 → 764.500
✅	agent_deb_amd64_fips	+12.44 KiB (0.00% increase, -0.37% of buffer)	712.473 → 712.485 → 715.740
✅	agent_msi	+15.0 KiB (0.00% increase, -0.08% of buffer)	643.578 → 643.592 → 660.960
✅	agent_rpm_amd64	+12.5 KiB (0.00% increase, -0.25% of buffer)	759.600 → 759.612 → 764.470
✅	agent_rpm_amd64_fips	+12.44 KiB (0.00% increase, -0.37% of buffer)	712.457 → 712.469 → 715.740
✅	agent_rpm_arm64	+8.5 KiB (0.00% increase, -0.70% of buffer)	735.359 → 735.368 → 736.540
✅	agent_rpm_arm64_fips	+4.44 KiB (0.00% increase, -0.20% of buffer)	691.546 → 691.550 → 693.690
✅	agent_suse_amd64	+12.5 KiB (0.00% increase, -0.25% of buffer)	759.600 → 759.612 → 764.470
✅	agent_suse_amd64_fips	+12.44 KiB (0.00% increase, -0.37% of buffer)	712.457 → 712.469 → 715.740
✅	agent_suse_arm64	+8.5 KiB (0.00% increase, -0.70% of buffer)	735.359 → 735.368 → 736.540
✅	agent_suse_arm64_fips	+4.44 KiB (0.00% increase, -0.20% of buffer)	691.546 → 691.550 → 693.690
✅	docker_agent_amd64	+8.44 KiB (0.00% increase, -0.46% of buffer)	818.232 → 818.240 → 820.040
✅	docker_agent_arm64	+8.44 KiB (0.00% increase, -0.48% of buffer)	819.035 → 819.043 → 820.740
✅	docker_agent_jmx_amd64	+8.43 KiB (0.00% increase, -0.49% of buffer)	1009.129 → 1009.137 → 1010.800
✅	docker_agent_jmx_arm64	+8.44 KiB (0.00% increase, -0.45% of buffer)	998.585 → 998.593 → 1000.420
✅	docker_dogstatsd_amd64	+8.16 KiB (0.02% increase, -1.67% of buffer)	39.482 → 39.490 → 39.960
✅	docker_dogstatsd_arm64	+64.16 KiB (0.17% increase, -8.82% of buffer)	37.560 → 37.623 → 38.270
✅	docker_host_profiler_amd64	+2.72 KiB (0.00% increase, -0.02% of buffer)	305.814 → 305.817 → 317.690
✅	dogstatsd_deb_amd64	+8.16 KiB (0.03% increase, -0.82% of buffer)	30.224 → 30.231 → 31.200
✅	dogstatsd_deb_arm64	+8.16 KiB (0.03% increase, -0.60% of buffer)	28.247 → 28.255 → 29.580
✅	dogstatsd_rpm_amd64	+8.16 KiB (0.03% increase, -0.82% of buffer)	30.224 → 30.231 → 31.200
✅	dogstatsd_suse_amd64	+8.16 KiB (0.03% increase, -0.82% of buffer)	30.224 → 30.231 → 31.200
✅	iot_agent_deb_amd64	+4.09 KiB (0.01% increase, -0.38% of buffer)	46.467 → 46.471 → 47.530
✅	iot_agent_rpm_amd64	+4.09 KiB (0.01% increase, -0.38% of buffer)	46.468 → 46.472 → 47.530
✅	iot_agent_suse_amd64	+4.09 KiB (0.01% increase, -0.38% of buffer)	46.467 → 46.471 → 47.530

8 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_heroku_amd64	311.955 MiB
✅	docker_cluster_agent_amd64	210.475 MiB
✅	docker_cluster_agent_arm64	223.456 MiB
✅	docker_cws_instrumentation_amd64	7.439 MiB
✅	docker_cws_instrumentation_arm64	6.877 MiB
✅	docker_host_profiler_arm64	317.125 MiB
✅	iot_agent_deb_arm64	43.124 MiB
✅	iot_agent_deb_armhf	43.907 MiB

[jeremy-hanna]

👍 for agent-runtime owned files