Reland go_shim, replacing go runner by SDK's raw go

[rdesgroppes]

What does this PR do?

Reland #54887, which #54925 reverted after it broke E2E jobs on main.

To prevent that from happening again, changes to bazel/rules/go_shim/**/* and internal/tools/** now trigger E2E tests unconditionally.

Recalling that PR: go_shim wraps a tool so that PATH lookups of go reach Bazel's hermetic SDK, and so that the tool runs from the current working directory rather than the runfiles tree, superseding rules_multitool's cwd().
It wraps gotestsum and go_mod_tidy_all, the latter dropping the $(rlocationpath @rules_go//go) resolution it had grown for itself and moving to its own package, where the shim taking over //:go_mod_tidy_all leaves its py_binary the plain name.

Changed on top of it:

• PATH now holds the Go SDK's raw go (unwrapped), resolved through @rules_go//go:toolchain, in place of @rules_go//go (the runner),
• the wrapper exports GOROOT and sets GOTOOLCHAIN=local itself rather than leaning on .bazelrc, and RUNFILES_DIR goes away with the runner that needed it.

Motivation

Unbreak dda inv test on hosts whose ambient go differs from the one go.work requires,
reported by @vitkyrka and followed up by @pgimalac and @hush-hush. #54107 routed it through bazel run //internal/tools:gotestsum, bringing gotestsum under .bazelrc's --run_env=GOTOOLCHAIN=local while it still resolved go through PATH, so every invocation failed with go.work requires go >= 1.26.5 and exporting GOTOOLCHAIN=auto did not help.

That fix then broke main, because @rules_go//go is a runner rather than a go: it assigns cmd.Dir from $BUILD_WORKING_DIRECTORY on every exec, discarding the directory its caller chose. gotest-custom chooses one per test package, so each prebuilt E2E test binary ran at the repository root and no longer found its fixtures, failing on compose/data, usmtest/test_tags.ps1, testdataprovision and checks/shared-library/files.

The SDK's go honors its caller, which is the whole of the difference.

Describe how you validated your changes

On Linux, a child go invoked from test/new-e2e under the shim reports that module's go.mod, where #54887 reported the repository root's.
Building a program importing net/http through the shim links, confirming the SDK's sources and tools are reachable.

The reported reproducer still holds: with a stub announcing itself as go 1.24.0 first in PATH, tools reach go1.26.5 and never the stub, and bazel run //:go_mod_tidy_all -- -diff exits 0 across every module.

Additional Notes

Prepending to PATH has no declarative spelling: RunEnvironmentInfo carries static strings only, a key given in both environment and inherited_environment resolves to the inherited value, and replacing PATH outright would hide sh, cc, git and whatever else the toolchain reaches for.
Hence a (thin) wrapper reading the environment at runtime.

The runfiles mirror go_bin_for_host, rules_go's own definition of a runnable go: the SDK binary plus its headers, libs, sources and tools.

install_gotestsum and its per-platform variants keep extracting the raw binary, the shim being runfiles-bound and those tools driving pre-built test binaries through --raw-command, never resolving go.

[dd-octo-sts]

Gitlab CI Configuration Changes

⚠️ Diff too large to display on Github.

Changes Summary

Removed	Modified	Added	Renamed
0	139	0	0

ℹ️ Diff available in the job log.

[dd-octo-sts]

Files inventory check summary

File checks results against ancestor a0a423d7:

Results for datadog-agent_7.84.0~devel.git.225.730749e.pipeline.131281652-1_amd64.deb:

No change detected

Results for datadog-iot-agent_7.84.0~devel.git.225.730749e.pipeline.131281652-1_amd64.deb:

No change detected

[dd-octo-sts]

Static quality checks

✅ Please find below the results from static quality gates
Comparison made with ancestor a0a423d
📊 Static Quality Gates Dashboard
🔗 SQG Job

33 successful checks with minimal change (< 2 KiB)

	Quality gate	Current Size
✅	agent_deb_amd64	760.218 MiB
✅	agent_deb_amd64_fips	713.079 MiB
✅	agent_heroku_amd64	312.557 MiB
✅	agent_msi	644.203 MiB
✅	agent_rpm_amd64	760.201 MiB
✅	agent_rpm_amd64_fips	713.062 MiB
✅	agent_rpm_arm64	735.966 MiB
✅	agent_rpm_arm64_fips	692.153 MiB
✅	agent_suse_amd64	760.201 MiB
✅	agent_suse_amd64_fips	713.062 MiB
✅	agent_suse_arm64	735.966 MiB
✅	agent_suse_arm64_fips	692.153 MiB
✅	docker_agent_amd64	818.833 MiB
✅	docker_agent_arm64	819.642 MiB
✅	docker_agent_jmx_amd64	1009.731 MiB
✅	docker_agent_jmx_arm64	999.192 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_dogstatsd_amd64	39.482 MiB
✅	docker_dogstatsd_arm64	37.560 MiB
✅	docker_host_profiler_amd64	305.814 MiB
✅	docker_host_profiler_arm64	317.125 MiB
✅	dogstatsd_deb_amd64	30.224 MiB
✅	dogstatsd_deb_arm64	28.247 MiB
✅	dogstatsd_rpm_amd64	30.224 MiB
✅	dogstatsd_suse_amd64	30.224 MiB
✅	iot_agent_deb_amd64	46.475 MiB
✅	iot_agent_deb_arm64	43.127 MiB
✅	iot_agent_deb_armhf	43.910 MiB
✅	iot_agent_rpm_amd64	46.476 MiB
✅	iot_agent_suse_amd64	46.475 MiB

[chouetz]

Should we add some more paths?

[chouetz]

Include the shim implementation in E2E change rules

When a follow-up changes bazel/rules/go_shim/defs.bzl or either wrapper template without also touching internal/tools, this rule will not schedule the E2E jobs, even though tasks/gotest.py runs E2E tests through the shimmed //internal/tools:gotestsum target. Since the newly introduced shim code controls the working-directory behavior that previously broke E2E, add bazel/rules/go_shim/**/* to this change set so those runtime-only regressions are exercised before reaching main.

Useful? React with 👍 / 👎.

I suppose this remark is valuable

[cit-pr-commenter-54b7da]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Job ID: 702cc06c-5627-419c-99a3-02c65af0c90a

Baseline: 92f6b05
Comparison: 730749e
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	+1.29	[+1.04, +1.54]	1	Logs bounds checks dashboard
➖	quality_gate_security_no_fs_load	memory utilization	+0.10	[-0.06, +0.25]	1	Logs bounds checks dashboard
➖	quality_gate_idle	memory utilization	-0.04	[-0.16, +0.08]	1	Logs bounds checks dashboard
➖	quality_gate_private_action_runner	memory utilization	-0.06	[-0.18, +0.06]	1	Logs bounds checks dashboard
➖	quality_gate_security_mean_fs_load	memory utilization	-0.15	[-0.23, -0.08]	1	Logs bounds checks dashboard
➖	quality_gate_security_idle	memory utilization	-0.21	[-0.31, -0.10]	1	Logs bounds checks dashboard
➖	quality_gate_idle_all_features	memory utilization	-0.32	[-0.37, -0.28]	1	Logs bounds checks dashboard
➖	quality_gate_logs	% cpu utilization	-0.87	[-1.73, -0.02]	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	174.47MiB ≤ 178MiB	bounds checks dashboard
✅	quality_gate_idle	total_bytes_received	10/10	741.79KiB ≤ 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	515.47MiB ≤ 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	205.12MiB ≤ 229MiB	bounds checks dashboard
✅	quality_gate_logs	missed_bytes	10/10	0B = 0B	bounds checks dashboard
✅	quality_gate_logs	total_bytes_received	10/10	264.16MiB ≤ 292MiB	bounds checks dashboard
✅	quality_gate_metrics_logs	cpu_usage	10/10	358.43 ≤ 2000	bounds checks dashboard
✅	quality_gate_metrics_logs	intake_connections	10/10	18 ≤ 40	bounds checks dashboard
✅	quality_gate_metrics_logs	memory_usage	10/10	403.13MiB ≤ 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	71.84MiB ≤ 76MiB	bounds checks dashboard
✅	quality_gate_security_idle	cpu_usage	10/10	26.57 ≤ 100	bounds checks dashboard
✅	quality_gate_security_idle	memory_usage	10/10	325.65MiB ≤ 335MiB	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	cpu_usage	10/10	61.74 ≤ 200	bounds checks dashboard
✅	quality_gate_security_mean_fs_load	memory_usage	10/10	303.36MiB ≤ 314MiB	bounds checks dashboard
✅	quality_gate_security_no_fs_load	cpu_usage	10/10	20.45 ≤ 100	bounds checks dashboard
✅	quality_gate_security_no_fs_load	memory_usage	10/10	316.20MiB ≤ 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_metrics_logs, bounds check intake_connections: 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 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_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_logs, bounds check total_bytes_received: 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_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_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_idle_all_features, bounds check intake_connections: 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_private_action_runner, bounds check memory_usage: 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.