The RETURN trap added in the previous commit leaked out of the function and
killed every deploy on a SOPS-configured host.
A RETURN trap set inside a SOURCED function is not function-scoped: it persists
in the caller's shell after the function returns, and a RETURN trap also fires
when a `.`/source completes. deploy.sh sources /etc/thermograph.env six lines
after calling render_thermograph_secrets, which re-fired the trap at top level
where `tmp` -- function-local -- is unset. Under deploy.sh's `set -u` that is
fatal, and silent: that line already sends stderr to /dev/null, so the deploy
rendered secrets and then died with no diagnostic before pulling or rolling
anything.
Replaced with explicit `rm -f "$tmp"` on each exit path, plus a comment
recording why the tidier-looking trap is wrong here so it doesn't come back.
The original defect the trap was meant to fix stays fixed: the decrypt-failure
path removes the plaintext temp file before returning 1.
The write section now captures its status in `rc` and cleans up once, rather
than ending on `rm` -- as the last command it was masking a failed in-place
`cat` write to status 0, so a half-written /etc/thermograph.env would have
deployed as if it succeeded.
Verified in a container against the real call pattern (strict-mode caller,
source lib, call, then source the rendered env): success path returns 0 and the
caller survives the subsequent source; decrypt-failure path aborts the caller
with no /etc/thermograph.env written; both leave zero temp files.
No static analysis has ever run over the ~2k lines of shell that deploy,
provision secrets, and bootstrap hosts as root over SSH. Add shell-lint.yml
(pinned shellcheck v0.11.0 + sha256, -x, default severity, fail on any
finding) and fix everything it reports, plus two defects it structurally
cannot see.
Not path-filtered, matching secrets-guard's call: a backstop that only runs
when you expect it to isn't a backstop. Scripts are discovered with find, so
new ones are covered on landing. The version is pinned to a static release
rather than apt's, so a drifted shellcheck can't fail CI on an unrelated push.
render-secrets.sh: the mktemp holding DECRYPTED vault contents was only
removed on the success path and one failure branch, so a sops decrypt failure
left plaintext POSTGRES_PASSWORD in /tmp indefinitely on a live host. A RETURN
trap makes removal unconditional, and the two sops calls now `|| return 1`
explicitly instead of relying on the caller's set -e (a bare set -e abort
skips the trap). The function stays free of `set -e` itself -- it is sourced,
and shell options would leak into the caller.
autoscale.sh: ran `set -eu` without pipefail while piping docker stats into
awk, so a failed left side was swallowed and the loop scaled on empty input.
Promoted to pipefail with avg_cpu's failure treated as a missed sample, so a
daemon hiccup can't kill the autoscaler. Verified busybox ash in docker:27-cli
supports pipefail and the script still parses there.
capture-fixtures.sh: `jq . || cat` ran cat after jq had already consumed
stdin, silently writing a truncated fixture; now a real if/else that fails
loudly. deploy.sh/deploy-stack.sh: `# shellcheck source=` paths corrected for
the monorepo layout, and /etc/thermograph.env marked unfollowable (it is
rendered at deploy time and cannot exist at lint time).
