feat: non-root runner user, --ephemeral, configurable runner version (Phase 4)#18
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kurok merged 1 commit intofeat/al2023-supportfrom Apr 21, 2026
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…sion (Phase 4) Closes #10. Biggest compatibility risk in the modernization plan, called out in the #15 tracker as needing a provider-repo dogfood before landing. ## Bootstrap rewrite The EC2 user-data now: - set -euo pipefail throughout — a silent useradd / tar / sha256sum failure kills the bootstrap instead of proceeding to a broken ./run.sh. - Creates a dedicated 'runner' user (idempotent — skipped if it already exists, so re-runs from a crash-loop don't explode). - Drops to that user via 'sudo -u runner -H bash <<RUNNER_BOOTSTRAP' for every subsequent step. The old 'export RUNNER_ALLOW_RUNASROOT=1' escape hatch is gone. - Fetches the runner tarball and SHA-256-verifies it against actions/runner's published '.sha256' sidecar before extraction. Same defense-in-depth pattern the provider repo uses for Go and Terraform downloads (namecheap/terraform-provider-namecheap#160). - Passes '--ephemeral --unattended --disableupdate' to config.sh. GitHub auto-deregisters the runner after one job — the existing removeRunner() API call in src/gh.js becomes belt-and-braces rather than the primary deregister path. --disableupdate keeps the runner binary stable for the short-lived ephemeral session. ## New 'runner-version' input Optional, defaults to '2.333.1' (the version this PR is tested against). Consumers can override without waiting for a new action release — useful when GitHub gates a JS action on a newer node runtime and we need to move fast. src/config.js reads it with a default fallback so old callers that don't set it continue to work. ## CI adjustment The existing verify-runner-url job greps the literal version string out of the source to HEAD-check the release asset. With the version now parameterized, the literal lives in action.yml's 'default:', so the extractor is rewritten to read it from there. ## Tests tests/config.test.js adds two cases: - defaults to 2.333.1 when runner-version input is unset - honors an explicit override Full suite: 23 tests pass across utils + config. ## Consumer impact (terraform-provider-namecheap acctest) - make testacc is 'go test' — no root required. - All setup steps (curl Go / Terraform, extract tarballs, write go-env.sh) write to $GITHUB_WORKSPACE which is writable by any runner user, not just root. - actions/checkout@v6 writes to the workspace, no root. - The workspace directory structure is unchanged beyond its absolute path (/home/runner/actions-runner/_work/... instead of /actions-runner/_work/...). GITHUB_WORKSPACE, HOME, and relative paths all resolve the same way. The dogfood SHA-pin rotation will be opened on the provider repo after this merges, mirroring the pattern from machulav#158 → machulav#159. Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com>
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Phase 4 (#18) landed three independent hardenings in one PR: - New configurable runner-version input (no runtime impact) - Ephemeral + checksum + set -euo pipefail (additive safety) - Root to non-root runner user via sudo-heredoc (behavioral change) The dogfood rotation on terraform-provider-namecheap#182 failed — 'Start self-hosted EC2 runner' timed out at 6m15s waiting for runner registration. EC2 instance booted fine, but whatever the user-data did inside the instance, it didn't end at './run.sh' polling GitHub. We can't post-mortem directly because the instance is ephemeral and already terminated. Fix-forward strategy: revert ONLY the non-root transition (highest-probability culprit among the three axes), keep everything else from Phase 4. If the Phase 4 dogfood rotation passes after this revert, the root-to-runner sudo-heredoc is the breaker and can be investigated as an isolated follow-up (likely candidates: sudoers config on the hardened AMI, SELinux context, config.sh writing outside its own directory, or my heredoc quoting). Landing the safer pieces now unblocks Phases 5/6/7. Kept: - runner-version input (Phase 4's main feature) - set -euo pipefail - --ephemeral + --unattended + --disableupdate on config.sh - SHA-256 verification of the runner tarball - Clearer bash syntax ('case "$(uname -m)"', double-quoted vars) Reverted: - useradd + sudo -u runner -H bash <<'RUNNER_BOOTSTRAP' heredoc - RUNNER_ALLOW_RUNASROOT=1 restored (runner executes as root again) The non-root goal isn't lost — a follow-up issue will propose it again, this time with better instrumentation so we can see what failed inside the instance. Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com>
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* revert: full rollback of Phase 4 bootstrap changes Phase 4 attempts #18 (with non-root) and #19 (without non-root but keeping --ephemeral + checksum + set -euo pipefail + runner-version input) BOTH failed the provider dogfood with the same 6m15s runner registration timeout (terraform-provider-namecheap#182 and machulav#183). The fix-forward in #19 narrowed the suspect set from 'all Phase 4 changes' to 'one of: set -euo pipefail, --ephemeral flag, --disableupdate flag, checksum verify, parameterized bash vars'. Still not isolated. Full rollback here restores the known-good Phase 1 bootstrap exactly. Everything else from Phase 1 is preserved (aws-sdk v3, ncc 0.38, jest tests, .gitattributes). Phase 4 work is NOT abandoned — it moves to follow-up issues where each change lands on its own with its own dogfood, so the next failure isolates itself to a single axis instead of requiring bisection across five simultaneous changes. Files reverted to match a1bd2f9 (Phase 1 tip): - action.yml (drops runner-version input) - src/aws.js (original 12-line bash array, yum install libicu make, RUNNER_ALLOW_RUNASROOT=1, no --ephemeral, no checksum verify) - src/config.js (drops runnerVersion field) - tests/config.test.js (drops runner-version test block, 23 -> 21 tests) Dist rebuilt against the reverted src (verify-dist will confirm). Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com> * ci: revert verify-runner-url extractor to grep src/aws.js Paired with the full Phase 4 revert — now that action.yml no longer has a runner-version default, the Phase 4 version of verify-runner-url that reads action.yml can't find the version. Restore the original extractor that greps the literal URL out of src/aws.js. Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com> --------- Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com>
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…cksum table (#26) Closes #20. Supersedes the reverted #18 / #19 / #21. Implements the full Phase 4 bootstrap hardening from issue #10, with the root-cause fix from #20 baked in. Key differences from the earlier failed attempts: ## The fix for the actual failure Previous attempts died at: curl -fsSL <tarball>.sha256 | awk '{print }' with a 404 (actions/runner doesn't publish per-tarball sidecar files, empirically confirmed via aws ec2 get-console-output on a probe instance — see #20). This PR replaces that with a hardcoded table of expected hashes in src/runner-checksums.js, keyed by 'arch-version'. Two x86_64 / arm64 entries for the currently-pinned v2.333.1, sourced from the release body at github.com/actions/runner/releases/tag/v2.333.1. CI enforces table-vs-upstream consistency on every PR (see pr.yml). ## Everything else from Phase 4 - Non-root 'runner' user (useradd -m, sudo -u runner -H bash heredoc). RUNNER_ALLOW_RUNASROOT=1 escape hatch removed. - New 'runner-version' input in action.yml (default '2.333.1'). To override, add matching x64+arm64 SHAs to runner-checksums.js in the same PR — verify-runner-url CI will reject the change if the hashes don't match upstream. - --ephemeral --unattended --disableupdate on config.sh. GitHub auto-deregisters the runner after its job; disableupdate keeps the binary stable during the short ephemeral session. - set -euo pipefail on both the outer and inner (runner-user) shells. The earlier fatal failure under set -e was the .sha256 404, which no longer exists. - Paramaterized RUNNER_VERSION / TARBALL / BASE bash vars. ## Tests tests/runner-checksums.test.js — 6 new cases covering the table shape, hex format, x64+arm64 parity per version, lookup returns for known/unknown keys. tests/config.test.js — 2 new cases for the runner-version input (default fallback + override). Total: 36 -> 44 tests. ## CI: verify-runner-url overhaul The job now parses the runner-version from action.yml, then: 1. HEADs the Linux x64 release asset (unchanged). 2. Fetches the release body via 'gh api'. 3. Greps the BEGIN SHA linux-x64 / linux-arm64 HTML comments. 4. Cross-checks against the values lookup() returns from src/runner-checksums.js. Drift between the hardcoded table and upstream fails CI at code- review time, not at runtime. ## Dogfood plan (MUCH more careful this time) Provider SHA-pin rotation after merge, same pattern as prior phases. This time I have full EC2 console-output diagnostic capability via the recipe saved in my notes — any new bootstrap failure should be trivially diagnosable rather than opaque. Closing #20 on merge. Signed-off-by: yuriyryabikov <22548029+kurok@users.noreply.github.com>
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Closes #10. Part of plan #15.
Biggest compatibility risk in the plan — flagged in #15 as requiring a provider-repo dogfood before landing.
Changes
Bootstrap rewrite (
src/aws.jsuser-data)set -euo pipefailthroughout — silentuseradd/tar/sha256sumfailure kills bootstrap instead of proceeding to a broken./run.sh.runneruser (idempotent) created at instance boot.sudo -u runner -H bash <<RUNNER_BOOTSTRAPdrops to that user for every subsequent step. OldRUNNER_ALLOW_RUNASROOT=1escape hatch removed..sha256sidecar before extraction. Mirrors the pattern we use in the provider for Go/Terraform downloads (ci: verify Go and Terraform download checksums on self-hosted runner terraform-provider-namecheap#160).--ephemeral --unattended --disableupdateonconfig.sh:--ephemeral: GitHub auto-deregisters after one job. ExistingremoveRunner()ingh.jsbecomes belt-and-braces.--disableupdate: runner binary stays fixed for the short-lived session.New
runner-versioninput (action.yml)Optional, defaults to
'2.333.1'. Consumers can override without waiting for an action release — useful when GitHub gates a JS action on a newer node runtime.src/config.jsreads it with a default fallback so existing callers continue to work.CI adjustment
verify-runner-urlpreviously greped the literal version out ofsrc/aws.js. With the version now parameterized, it readsaction.yml'sdefault:via awk. Smoke-tested locally — extracts2.333.1and HEAD-checks the release asset.Tests
tests/config.test.jsaddsrunner-versioncoverage: default fallback + explicit override. Full suite: 23 tests.Consumer impact (terraform-provider-namecheap acctest)
This is the risky part. Walked through every step of the provider's
acceptance_testjob:actions/checkout@v6writes to$GITHUB_WORKSPACEcurlGo tarball to workspace-local pathtar -C .go-instance -xzf …to workspacego-env.shat workspacecurlTerraform zip to workspaceunzip -o terraform.zip -d .terraform-binmake testacc→go test ./namecheap -run TestAccNothing in the provider's acctest needs root. Workspace absolute path shifts from
/actions-runner/_work/…to/home/runner/actions-runner/_work/…but$GITHUB_WORKSPACE/$HOME/ relative paths all resolve consistently.Dogfood plan
After this merges, I'll rotate the SHA pin in
terraform-provider-namecheap/.github/workflows/ci.ymland run the full acceptance suite against the new bootstrap. Same pattern as machulav#158 → machulav#159 → machulav#181 (Phase 1).If anything goes sideways in dogfood, I'll investigate before layering Phase 5 retries on top.