Adversarial review of 9db25ba60 found four residual defects in the
auto-update asset install, plus a doc line it left contradicting itself.
- install_auto_update_assets copied the bundled helper into the staged
mktemp file with an unchecked cp, and both call sites invoke the
function under `if !`, which suppresses errexit for its whole body. A
failed copy (ENOSPC, EIO) fell through to
configure_auto_update_script_repo, whose awk emits a lone GITHUB_REPO=
line for empty input, so a shebang-less one-line stub replaced the
working helper with a "script" that only ever exits 0 - silently
disabling unattended updates. Check the cp, and refuse the swap unless
the staged helper is non-empty and starts with #!.
- Both units were rendered with a bare truncating `cat > "$unit"` whose
status was never checked, and the function's last statement is
safe_systemctl daemon-reload, which returns 0 by design. A failing
write truncated a working unit and still reported success. Render each
unit to ${path}.tmp and commit it with a checked rename, so a failure
leaves the installed unit byte-identical.
- The widened ReadWritePaths could not reach deployed boxes: the unit
that grants the write access is itself the file that has to be
rewritten, and on an existing install the sandbox running the
installer excludes /etc/systemd/system and /usr/local/bin (EROFS). The
Go update pipeline cannot carry it either - pulse.service runs as
User=pulse with its own ProtectSystem=strict over the install and
config dirs only. So probe each destination directory up front and,
when one is blocked, re-exec this already-signature-verified installer
through systemd-run with a new internal --repair-auto-update-units
entry point: PID 1 forks the transient unit, so it starts in the host
mount namespace instead of inheriting the sandbox. The installer is
copied into the install dir first because the calling unit's
PrivateTmp=yes hides its /tmp copy from PID 1. The escape needs root
and systemd-run, and never recurses.
- Keep the ReadWritePaths entries as directory grants: every write now
commits with a rename from a sibling staging file, and rename needs
write access on the containing directory, so the file-level entries
systemd would otherwise accept cannot work. Document the tradeoff in
the unit and the subsystem contract instead.
The deployment-installability contract still claimed the update sandbox
leaves "only the install dir, config dir and /tmp" writable, which the
paragraph the same file gained in 9db25ba60 contradicts; the same stale
rationale had been copied into two test comments.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Two bugs from #1630 that combined to take installs down silently:
1. perform_update()'s install-failed rollback branch restored the backup
but never restarted pulse.service. Since the generated
pulse-update.service gates on ExecCondition=systemctl is-active,
every later timer run was then skipped and the install stayed down
until manual intervention. Restart is now guaranteed by a
service_was_active-guarded restart in that branch plus an
ensure_service_restarted RETURN trap so no exit path can miss it
(re-fix of #1323, originally c0b3a0e66, lost in 778a2577b and only
partially restored in 672e81985).
2. install.sh aborted under errexit when writing the /bin/update helper
on a read-only filesystem - after the new binary was installed and
the service stopped, landing in bug 1's no-restart branch. The stock
pulse-update.service uses ProtectSystem=strict, so /bin and
/usr/local/bin are read-only on stock unattended updates; transient
read-only remounts hit the same path. The helper write, PATH
appends, and the /usr/local/bin/pulse symlink are now idempotent and
non-fatal with a warning (install_binary_symlink).
Contract: deployment-installability now pins fail-closed service
availability for unattended updates and non-fatal writes outside the
hardened unit's writable set, with proofs in pulse_auto_update_test.go
and root_install_sh_test.go plus shell regression coverage in
scripts/tests/test-pulse-auto-update.sh (installer-exits-nonzero path)
and scripts/tests/test-install-update-resilience.sh (read-only helper
and symlink paths, verified under set -e, root-safe via ENOTDIR).
Fixes#1630
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Finishes the deferred half of the v5->v6 parity fix for #1323 (the
pulse-auto-update.sh half landed in 672e81985). The interactive install.sh
update/reinstall flow stopped a running Pulse then called start_pulse, which
tolerates a silent start failure (common on unprivileged LXC) by printing a note
and returning 0 — leaving Pulse stopped under an "installation completed!" message.
- stop_pulse_for_update records whether Pulse was running before the update.
- start_pulse, only when Pulse was running before (PULSE_WAS_ACTIVE), no longer
accepts a silent start failure: it verifies the service became active
(wait_for_service_active, 20s), retries one explicit start, and surfaces a clear
error + diagnostics if it still will not come up. Fresh installs are unchanged
(the flag stays false, so the reassuring container note is kept).
- Wired into all three update/reinstall sites; added a BASH_SOURCE guard so the
installer's functions can be unit-tested without running the installer.
Scope: fixes the #1323 'restart silently failed' case. Does NOT add a binary
rollback (download_pulse deletes bin/pulse.old right after the swap) — a
bad-release rollback is a separate concern.
Test: scripts/tests/test-install-update-resilience.sh (sources install.sh, stubs
systemctl, asserts was-active capture + retry + clear error). Go installtests +
bash -n confirm the guard does not change installer execution.
courtmanr@gmail.com