Replace custom golangci-lint build with depguard rule

[rdesgroppes]

What does this PR do?

Migrate the custom pkgconfigusage plugin for golangci-lint to an equivalent depguard rule, eliminating the need for rebuilding golangci-lint from downloaded sources.

Changes:

• migration of pkgconfigusage itself, from a golangci-lint plugin ([ASCII-2155] add custom go linter to check usage of pkgconfig inside component folder #28382, [AGENTRUN-600] update pkgconfigusage linter to use pkg/config/setup package #39367) to a rule for the depguard (v2) plugin, while preserving its name for traceability,
• move file exclusions to that rule configuration, while removing those that no longer exist or are no longer violating the rule:
  • comp/aggregator/demultiplexer/demultiplexerimpl/test_agent_demultiplexer.go,
  • comp/core/agenttelemetry/impl/config.go,
  • comp/core/config/config_mock.go,
  • comp/core/workloadfilter/def/utils.go,
  • comp/core/workloadmeta/collectors/internal/process/process_collector.go,
  • comp/core/workloadmeta/collectors/util/process_util_linux.go,
  • comp/dogstatsd/listeners/udp.go,
  • comp/remote-config/rcservice/rcserviceimpl/rcservice.go,
  • comp/remote-config/rcservicemrf/rcservicemrfimpl/rcservicemrf.go,
• conversely move locally inhibited // nolint:pkgconfigusage to file exclusions:
  • comp/core/config/params.go,
  • comp/core/workloadfilter/baseimpl/filter_utils.go,
  • comp/core/workloadfilter/catalog/filter_config.go,
• update pkgconfigusage_test to validate the effectiveness of the rule configuration defined in .golangci.yml,
• remove custom golangci-lint build infrastructure.

Motivation

This change kills several birds with one stone:

1. preparation step for the Go build migration to Bazel (ABLD-317): while looking for an isolated component with minimal dependencies to introduce the first Go toolchain as part of the ongoing Bazel migration, the custom golangci-lint build initially seemed to be a good candidate, but it turns out we can spare time by removing the said build at all,
2. standardization: the golangci-lint v2 upgrade (Upgrade golangci-lint from v1.60.3 to v2.6.2 #43501) introduced depguard v2 support with file-based import restrictions using glob patterns, enabling the same architectural enforcement without a custom plugin,
3. reliability: the custom plugin build process obviously takes time and occasionally failed in CI and locally with:

   Error: build process: clone golangci-lint: git clone --branch v2.7.0 --single-branch --depth 1 -c advice.detachedHead=false -q https://github.com/golangci/golangci-lint.git: exit status 128
   

   (example CI log)

Describe how you validated your changes

First commit had pkgconfigusage_test validating the actual rule configuration defined in .golangci.yml by parsing it and running the depguard analyzer based on the existing analysistest.Run() tool with // want comments in sample files:

datadog-agent/pkg/linters/testdata/src/comp/a.go

Line 9 in ed57377

import _ "github.com/DataDog/datadog-agent/pkg/config/setup" // want `pkg/config/setup should not be used inside comp folder`

The second commit removed this test as per review comments. It however remains possible to verify the pkgconfigusage rule works as expected by simply removing a file from the exclusions and the linter will spot it.

[pgimalac]

Nice !

[agent-platform-auto-pr]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor 8766844
📊 Static Quality Gates Dashboard

31 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64	752.511 MiB
✅	agent_deb_amd64_fips	701.180 MiB
✅	agent_heroku_amd64	326.974 MiB
✅	agent_msi	663.055 MiB
✅	agent_rpm_amd64	752.495 MiB
✅	agent_rpm_amd64_fips	701.164 MiB
✅	agent_rpm_arm64	731.268 MiB
✅	agent_rpm_arm64_fips	683.256 MiB
✅	agent_suse_amd64	752.495 MiB
✅	agent_suse_amd64_fips	701.164 MiB
✅	agent_suse_arm64	731.268 MiB
✅	agent_suse_arm64_fips	683.256 MiB
✅	docker_agent_amd64	814.612 MiB
✅	docker_agent_arm64	817.976 MiB
✅	docker_agent_jmx_amd64	1005.491 MiB
✅	docker_agent_jmx_arm64	997.574 MiB
✅	docker_cluster_agent_amd64	181.112 MiB
✅	docker_cluster_agent_arm64	196.918 MiB
✅	docker_cws_instrumentation_amd64	7.135 MiB
✅	docker_cws_instrumentation_arm64	6.689 MiB
✅	docker_dogstatsd_amd64	38.840 MiB
✅	docker_dogstatsd_arm64	37.128 MiB
✅	dogstatsd_deb_amd64	30.059 MiB
✅	dogstatsd_deb_arm64	28.204 MiB
✅	dogstatsd_rpm_amd64	30.059 MiB
✅	dogstatsd_suse_amd64	30.059 MiB
✅	iot_agent_deb_amd64	43.037 MiB
✅	iot_agent_deb_arm64	40.135 MiB
✅	iot_agent_deb_armhf	40.705 MiB
✅	iot_agent_rpm_amd64	43.038 MiB
✅	iot_agent_suse_amd64	43.038 MiB

On-wire sizes (compressed)

	Quality gate	Change	Size (prev → curr → max)
✅	agent_deb_amd64	-6.89 KiB (0.00% reduction)	183.949 → 183.943 → 184.810
✅	agent_deb_amd64_fips	+44.23 KiB (0.03% increase)	172.616 → 172.659 → 173.790
✅	agent_heroku_amd64	+10.16 KiB (0.01% increase)	87.157 → 87.167 → 88.450
✅	agent_msi	-16.0 KiB (0.01% reduction)	143.152 → 143.137 → 143.300
✅	agent_rpm_amd64	+3.75 KiB (0.00% increase)	186.830 → 186.833 → 188.160
✅	agent_rpm_amd64_fips	-19.55 KiB (0.01% reduction)	175.731 → 175.712 → 176.600
✅	agent_rpm_arm64	-40.35 KiB (0.02% reduction)	168.625 → 168.586 → 169.930
✅	agent_rpm_arm64_fips	+19.47 KiB (0.01% increase)	159.172 → 159.191 → 160.550
✅	agent_suse_amd64	+3.75 KiB (0.00% increase)	186.830 → 186.833 → 188.160
✅	agent_suse_amd64_fips	-19.55 KiB (0.01% reduction)	175.731 → 175.712 → 176.600
✅	agent_suse_arm64	-40.35 KiB (0.02% reduction)	168.625 → 168.586 → 169.930
✅	agent_suse_arm64_fips	+19.47 KiB (0.01% increase)	159.172 → 159.191 → 160.550
✅	docker_agent_amd64	neutral	276.622 MiB → 277.400
✅	docker_agent_arm64	neutral	264.051 MiB → 266.040
✅	docker_agent_jmx_amd64	neutral	345.260 MiB → 346.020
✅	docker_agent_jmx_arm64	neutral	328.667 MiB → 330.660
✅	docker_cluster_agent_amd64	neutral	63.994 MiB → 64.490
✅	docker_cluster_agent_arm64	neutral	60.256 MiB → 61.170
✅	docker_cws_instrumentation_amd64	neutral	2.994 MiB → 3.330
✅	docker_cws_instrumentation_arm64	neutral	2.726 MiB → 3.090
✅	docker_dogstatsd_amd64	neutral	15.031 MiB → 15.820
✅	docker_dogstatsd_arm64	neutral	14.356 MiB → 14.830
✅	dogstatsd_deb_amd64	neutral	7.946 MiB → 8.790
✅	dogstatsd_deb_arm64	neutral	6.825 MiB → 7.710
✅	dogstatsd_rpm_amd64	neutral	7.958 MiB → 8.800
✅	dogstatsd_suse_amd64	neutral	7.958 MiB → 8.800
✅	iot_agent_deb_amd64	+2.25 KiB (0.02% increase)	11.290 → 11.292 → 12.040
✅	iot_agent_deb_arm64	+2.41 KiB (0.02% increase)	9.651 → 9.653 → 10.450
✅	iot_agent_deb_armhf	+2.64 KiB (0.03% increase)	9.844 → 9.847 → 10.620
✅	iot_agent_rpm_amd64	+2.09 KiB (0.02% increase)	11.308 → 11.310 → 12.060
✅	iot_agent_suse_amd64	+2.09 KiB (0.02% increase)	11.308 → 11.310 → 12.060

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: f711be68-9c26-4599-9dc7-5216ca2cef4a

Baseline: 8766844
Comparison: 4978078
Diff

Optimization Goals: ✅ No significant changes detected

Experiments ignored for regressions

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

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	docker_containers_cpu	% cpu utilization	+1.64	[-1.47, +4.75]	1	Logs

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	tcp_syslog_to_blackhole	ingress throughput	+2.21	[+2.12, +2.30]	1	Logs
➖	docker_containers_cpu	% cpu utilization	+1.64	[-1.47, +4.75]	1	Logs
➖	quality_gate_metrics_logs	memory utilization	+1.47	[+1.24, +1.70]	1	Logs bounds checks dashboard
➖	uds_dogstatsd_20mb_12k_contexts_20_senders	memory utilization	+0.41	[+0.35, +0.46]	1	Logs
➖	file_tree	memory utilization	+0.28	[+0.23, +0.33]	1	Logs
➖	ddot_metrics_sum_delta	memory utilization	+0.25	[+0.05, +0.44]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	+0.06	[-0.37, +0.48]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	+0.03	[-0.45, +0.51]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	+0.01	[-0.04, +0.06]	1	Logs
➖	uds_dogstatsd_to_api_v3	ingress throughput	+0.01	[-0.11, +0.13]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	+0.01	[-0.09, +0.10]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.13, +0.13]	1	Logs
➖	otlp_ingest_metrics	memory utilization	-0.02	[-0.17, +0.13]	1	Logs
➖	quality_gate_idle	memory utilization	-0.05	[-0.10, +0.00]	1	Logs bounds checks dashboard
➖	docker_containers_memory	memory utilization	-0.05	[-0.12, +0.03]	1	Logs
➖	ddot_logs	memory utilization	-0.06	[-0.12, -0.01]	1	Logs
➖	ddot_metrics_sum_cumulativetodelta_exporter	memory utilization	-0.12	[-0.35, +0.11]	1	Logs
➖	ddot_metrics	memory utilization	-0.14	[-0.35, +0.08]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.14	[-0.52, +0.24]	1	Logs
➖	ddot_metrics_sum_cumulative	memory utilization	-0.19	[-0.35, -0.03]	1	Logs
➖	otlp_ingest_logs	memory utilization	-0.21	[-0.31, -0.11]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-0.41	[-0.44, -0.37]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.41	[-1.89, +1.07]	1	Logs bounds checks dashboard

Bounds Checks: ✅ Passed

perf	experiment	bounds_check_name	replicates_passed	links
✅	docker_containers_cpu	simple_check_run	10/10
✅	docker_containers_memory	memory_usage	10/10
✅	docker_containers_memory	simple_check_run	10/10
✅	file_to_blackhole_0ms_latency	lost_bytes	10/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	lost_bytes	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	lost_bytes	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_logs	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	lost_bytes	10/10	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	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_metrics_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_metrics_logs, bounds check lost_bytes: 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 intake_connections: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check lost_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 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 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.

[Ishirui]

Woot !

[rdesgroppes]

/merge

[gh-worker-devflow-routing-ef8351]

View all feedbacks in Devflow UI.

2026-01-27 10:53:17 UTC ℹ️ Start processing command /merge

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2026-01-27 10:53:23 UTC ℹ️ MergeQueue: pull request added to the queue

The expected merge time in main is approximately 59m (p90).

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2026-01-27 11:37:47 UTC ℹ️ MergeQueue: This merge request was merged