ci: one step for the CI toolchain - atmos toolchain install from .tool-versions, cached by atmos ci cache - #3041
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Andriy Knysh (aknysh) merged 29 commits intoSep 5, 2026
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…st OS endpoints Windows jobs have been finishing every step, including "Post Harden Runner" and "Complete job", and then never reporting a conclusion until GitHub cancels them 30-40 minutes later (0/day before harden-runner landed on the Windows legs on Aug 31; 5, 9, 23/day on Sept 1-3). Root cause: harden-runner's Windows post step waits at most 10 s for its agent, then kills it, and in the losing case the agent is still restoring the runner's DNS settings, leaving the adapter pointed at a DNS proxy that no longer exists. - Add .github/actions/windows-dns-guard: a scheduled-task watchdog that resets DNS only once harden-runner's post step has begun, the agent is gone, and 127.0.0.1 is still configured. Wired into every Windows leg. - Allowlist the Windows/macOS operating-system endpoints StepSecurity showed blocked on every job (NCSI probes, WNS, update/settings/telemetry, time sync, Sectigo OCSP/CRL, Apple update/CDN hosts); harden-runner stays in block mode everywhere. - Drop the GOPROXY "|direct" fallback in block-mode workflows: it only fans out to blocked vanity-import hosts. - Cancel superseded pull_request runs via a concurrency group. - Skip SARIF uploads on merge_group runs, whose synthetic ref cannot be scanned and was evicting PRs from the merge queue. Fix log: docs/fixes/2026-09-03-harden-runner-windows-dns-restore-race.md Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
The pool advertises four rotating names (0-3.pool.ntp.org); a single one was only what happened to be sampled. Push deferred until the first CI run of the guard finishes so its Windows data isn't cancelled by the new concurrency group. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
- Skip Harden Runner on draft-PR Windows jobs: every other Windows step (including checkout) is already skipped there, so its post step would race the agent's DNS restore with no guard available. - Run the guard's scheduled task as the runner's own Administrator account (S4U) instead of SYSTEM; it grants nothing the job does not already have. - Wrap the plain go mod download steps in pre-commit.yml and codeql.yml with go-mod-download-retry now that GOPROXY has no direct fallback. - Measurement query: filter to Windows jobs and tolerate fractional-second timestamps. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
…hards
Phase 2 (part 1) of the CI-stability plan, stacked on the Phase 1 branch.
Windows Defender: on the Windows shards "Set up Go" averages 5.2 min
(max 10.5) restoring a 1.9 GB go-build+mod cache; the download is ~20 s,
the rest is tar/zstd extraction with Defender's real-time scanner
inspecting every extracted file, and the same scanner holding handles on
fresh test files surfaces as testing.TempDir cleanup failures
("unlinkat ... being used by another process"). Add a continue-on-error
pwsh step to every Windows leg of test.yml (build, terraform-registry-cache,
test, mock) and to setup-go-cache-warmup.yml that excludes D:\a,
C:\hostedtoolcache\windows, the Go caches, and the temp dirs, plus go.exe
as a process. These are ephemeral VMs and the step does not touch
harden-runner's egress policy.
Restore-only toolchain cache: the repo's Actions cache is 18.9 GB across
17 refs/pull/N/merge-scoped entries against a 10 GB LRU quota, so the
static atmos-toolchain-<os>-<arch>-v2 key never hits ("Cache not found
for input keys" on every shard), then all 10 shards race to save it
("Unable to reserve cache with key ...") and "Post Cache Atmos toolchain"
costs 43 s avg / 3 min max per shard for nothing. Add an opt-in
restore-only input (default 'false') to actions/cache/action.yml that
switches to actions/cache/restore at the same pinned SHA, keep cache-hit
and key outputs working, document it in the README, and set it on the
test job's "Cache Atmos toolchain" step for all three OSes.
terraform-registry-cache stays the single writer per OS and is unchanged.
Fix log: docs/fixes/2026-09-03-windows-defender-exclusions-and-restore-only-toolchain-cache.md
Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Every acceptance shard, terraform-registry-cache leg and mock job ran the five `atmos toolchain install --default ...` commands (~400 MB of release downloads, ~2 min, per job) because the toolchain cache never hits: the Go caches churn the 10 GB Actions cache first. Install the tools once in the build job, ship `toolchain/bin` as a `toolchain-<target>` artifact (1-day retention), and have the consumers unpack it into their toolchain cache before installing. The consumers install from a job-local tool-versions file instead of per tool: only `installFromToolVersions` takes the "already installed" skip path, while the per-tool `--default owner/repo@version` form always re-resolves, re-verifies and re-extracts (it hung offline even with the archive cached). Both forms live in a new composite action so the tool list stays identical between the build job and its consumers; a missing artifact degrades to the network install. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
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Warning SHA Pin Verification Passed — with documented exceptionsAll 232 third-party action reference(s) are covered, but 2 rely on a documented allowlist entry in
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Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Add-MpPreference -ExclusionProcess 'go.exe' matches on image name only, not path, so it would exempt any binary named go.exe from real-time scanning regardless of where it actually lives - including one planted by a compromised dependency during go build/go generate. The path exclusions already in this step cover the actual scanning cost (file I/O in the Go caches and workspace), so removing the process exclusion gives up nothing measured. (Skipped a second CodeRabbit finding on this PR: it asked test/ terraform-registry-cache to needs: a "cache-writer" job that doesn't exist in this file - terraform-registry-cache itself is the writer, and test is deliberately parallel to it so 30 shards don't wait on or race the single writer job. Making test depend on it would serialize two long-running job groups that currently run concurrently.) Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
The mock job only requests opentofu/opentofu (plus the terraform ci-toolchain always adds) - not packer/helm/helmfile like the test and terraform-registry-cache jobs. The Changes section already said this correctly; only the Summary paragraph overstated it. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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💥 This pull request now has conflicts. Could you fix it Erik Osterman (Cloud Posse) (@osterman)? 🙏 |
Codecov Report✅ All modified and coverable lines are covered by tests. Additional details and impacted files@@ Coverage Diff @@
## main #3041 +/- ##
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- Coverage 83.83% 83.83% -0.01%
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Files 1982 1982
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- Hits 162452 162446 -6
- Misses 23358 23366 +8
+ Partials 7970 7968 -2
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…-in-build-artifact # Conflicts: # .github/workflows/setup-go-cache-warmup.yml # .github/workflows/test.yml # docs/fixes/2026-09-03-harden-runner-windows-dns-restore-race.md
…efender-restore-only-cache # Conflicts: # .github/workflows/setup-go-cache-warmup.yml # .github/workflows/test.yml # docs/fixes/2026-09-03-harden-runner-windows-dns-restore-race.md
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Included review availability: Your plan provides up to 4 included reviews per hour; 3 remain after this review. 📝 WalkthroughWalkthroughThe CI toolchain action now reads ChangesCI cache and toolchain flow
Estimated code review effort: 3 (Moderate) | ~20 minutes Merge Risk: ⚪ Minimal · up to CI toolchain setup now installs pinned tools from Sequence Diagram(s)sequenceDiagram
participant Workflow
participant CiToolchain
participant AtmosCache
participant Toolchain
Workflow->>CiToolchain: select cache mode
CiToolchain->>AtmosCache: restore shared cache
AtmosCache-->>CiToolchain: return cache result
CiToolchain->>Toolchain: install from .tool-versions
Toolchain-->>CiToolchain: export tool paths
CiToolchain-->>Workflow: provide configured toolchain
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✨ Finishing Touches 💡 1🛠️ Fix failing CI checks 💡
🧪 Generate unit tests (beta)
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atmos toolchain install from .tool-versions installs every pinned tool, so the mock job needs the same download hosts as the test job when the toolchain cache misses (get.helm.sh was blocked and helm failed). With the cache in place the install is a no-op. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
…ulti-line args The fake container runtime wrote each invocation as one tab-joined line; a forwarded -e KEY=VALUE for a multi-line environment variable (ATMOS_CACHE_PATH, exported by the cache action for its nested post step) split the record and the container-override tests lost the interpreter fields on Windows shard 1. Newlines and tabs inside an argument are now escaped in the record. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
…tore-only-cache' into osterman/ci-toolchain-in-build-artifact
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Inline comments:
In `@docs/fixes/2026-09-03-restore-only-toolchain-cache-on-shards.md`:
- Line 20: Reconcile the toolchain cache figures in the cache-capacity analysis:
make the reported 18.9 GB aggregate consistent with the 14 entries at 1.6 GB and
8 entries at 0.35 GB, updating either the total or the per-entry ranges while
preserving the stated 22-entry count.
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…otal The per-entry ranges implied a floor above the reported 18.9 GB total (14 entries at a 1.6 GB floor alone is 22.4 GB). State them as upper bounds instead, since the original per-entry measurements are no longer reproducible (transient, already-evicted cache state).
Andriy Knysh (aknysh)
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💥 This pull request now has conflicts. Could you fix it Erik Osterman (Cloud Posse) (@osterman)? 🙏 |
Resolves conflicts against main's cache-action redesign (#3049) and the toolchain-env-export changes: this branch made no unique changes to actions/cache/action.yml (main is a strict superset), so took main's copy verbatim. Kept this branch's new ci-toolchain composite action step in test.yml in place of the old manual per-tool install + separate cache step. Kept main's fake_container_runtime.go recordArgs (no backslash-escaping, per the earlier revert that fixed Windows path-argument test breakage).
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what
.github/actions/ci-toolchainis now exactly what a developer runs, plus the cache atmos already describes: the Atmos Cache action (./actions/cache, driven byci.cache),atmos toolchain install(reads.tool-versions, skips what is on disk),atmos toolchain env --format=github. One input for the cache mode:saveon the one producer job per OS (thebuildjob, with the atmos it just built),restore-only(default) on every consumer.terraform-registry-cachelegs, themockjobs) is one step. Versions are pinned in.tool-versionsonly.restore-onlyon the published cache action), merged into this branch.why
Two things had grown around a three-command task. Versions were duplicated in workflow env vars that drifted from
.tool-versions(#3022 removed them; the first version of this PR still fed them into its action and would have written empty pins after merging main). And because the toolchain cache never survived the 10 GB Actions-cache churn, the first version built its own mechanism: tar the installed tree withcygpath-aware shell, upload atoolchain-<os>artifact, download and unpack it in every consumer - ~150 lines of shell doing what atmos already does.Atmos's cache is enough now: the repository's cache limit is 50 GB (raised after measuring that nothing survived a run at 10 GB), and
restore-onlyconsumers no longer race to save one key. A toolchain entry is ~400-600 MB per OS.Verified on this PR's runs.
atmos toolchain installfrom.tool-versionsinstalled all nine pinned tools in 13 s (Linux) and 23 s (Windows) on a cache miss, and the post-step save now storesatmos-toolchain-<os>-<arch>-v2(6 s / 5 s). That save only worked after a fix in the cache action: a post step of an action nested inside another composite cannot see the composite'ssteps.*.outputs(actions/runner#2800), so the first run saved nothing (Input required and not supplied: path); the action now exports key, paths and restore-keys through the job env. The mock job's egress allowlist gained the toolchain download hosts (it had been built for OpenTofu alone, andget.helm.shwas blocked on a miss).Note for reviewers: GitHub's Actions cache for this repo is currently read-only ("You have reached your configured budget") after the limit was raised past the included 10 GB; until the budget is raised, every hosted-runner job installs from the network and no save lands, which is the state the shards ran in on the latest run.
references
docs/fixes/2026-09-04-ci-toolchain-one-step.md🤖 Generated with Claude Code
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