## Thinking Path
> - Paperclip orchestrates AI agents for zero-human companies
> - The reference container image must be deployable on both Docker
Compose (where it starts as root and `gosu`'s a `USER_UID`/`USER_GID`
switch) and Kubernetes (where the pod is typically constrained by
PodSecurity)
> - The Kubernetes operator (paperclipinc/paperclip-operator#45) sets
`runAsNonRoot: true`, `runAsUser: 1000`, `allowPrivilegeEscalation:
false`, and `drop: ALL` capabilities by default — the unconditional
`usermod` + `gosu` flow in the entrypoint requires root + `CAP_SETUID` /
`CAP_SETGID`, making the image undeployable on any cluster enforcing
baseline or restricted PodSecurity
> - Without root, neither the user remap nor `gosu` can ever succeed —
so the fix is a runtime branch: non-root starts `exec` the command
directly (warning if the runtime UID/GID differs from the requested
one), while root starts keep the existing `usermod`+`gosu` flow
> - This also covers platforms that assign arbitrary UIDs (OpenShift
restricted SCC), which previously crashed with a cryptic `usermod:
Permission denied`
> - The benefit is one image that works for both deployment shapes with
no operator-side workaround — pure superset, no breaking change
## Linked Issues or Issue Description
Refs paperclipinc/paperclip-operator#45 (cross-repo) — the operator's
default pod security context (`runAsNonRoot: true`, `runAsUser: 1000`,
`allowPrivilegeEscalation: false`, `drop: ALL`) is blocked by this
entrypoint behavior. The operator shipped a stopgap
(paperclipinc/paperclip-operator#46 lets the CRD override the security
context); this PR is the image-side fix that makes the secure defaults
work out of the box. Supersedes #2904 (v1 of this branch).
No in-repo issue covers this directly — problem described in-PR
following the bug-report template:
**What happened**
The entrypoint unconditionally runs `usermod`/`groupmod`/`chown` + `exec
gosu node`, which requires root plus `CAP_SETUID` / `CAP_SETGID` — any
non-root start crashes (`gosu` cannot drop privileges; a mismatched UID
dies earlier at `usermod: Permission denied`), making the reference
image undeployable on clusters enforcing baseline or restricted
PodSecurity.
**Expected behavior**
A non-root container `exec`s the command directly (with a clear warning
if its UID/GID differs from the requested `USER_UID`/`USER_GID`, since a
remap is impossible without root). The existing root + `usermod` +
`gosu` flow is preserved for Docker Compose, where the container starts
as root and switches to the requested UID/GID.
**Deployment mode**
Kubernetes with baseline/restricted PodSecurity and OpenShift-style
arbitrary-UID platforms (failing cases); Docker Compose root-start (must
keep working).
## What Changed
- **`scripts/docker-entrypoint.sh`** — branch on the runtime UID:
- **Non-root start** → `exec "$@"` directly. If the runtime UID/GID
differs from `USER_UID`/`USER_GID`, print a one-line warning to stderr
first (the remap is impossible without root; the warning keeps
volume-permission mismatches diagnosable instead of failing cryptically
inside `usermod`).
- **Root start** → unchanged: `usermod`/`groupmod` remap when requested,
`chown` of `/paperclip` when a remap happened, then `exec gosu node
"$@"`.
## Verification
**Automated:** `server/src/__tests__/docker-entrypoint.test.ts` runs the
real entrypoint with `id`/`usermod`/`groupmod`/`chown`/`gosu` stubbed
via PATH and asserts all five privilege branches (root+defaults,
root+remap, non-root match, arbitrary non-root UID, GID mismatch) — runs
in the regular server suite, no Docker needed.
**Manual (Docker):** ran the entrypoint on `node:lts-trixie-slim` (the
image's actual base) across the full matrix, with `gosu` stubbed to a
marker:
- [x] Root start, defaults → no remap, `gosu node` invoked (Docker
Compose flow unchanged)
- [x] Root start, `USER_UID=1001`/`USER_GID=1001` → `Updating node
UID/GID to 1001` + `gosu node` (remap flow unchanged)
- [x] Non-root `--user 1000:1000` (the operator's `runAsUser: 1000`
shape) → silent direct exec, command runs as 1000:1000
- [x] Non-root `--user 1234:1234` (arbitrary UID) → warning `running
unprivileged as 1234:1234; cannot remap to requested 1000:1000`, then
direct exec (previously: crash)
- [x] Non-root `--user 1000:1001` (GID mismatch) → warning, then direct
exec
- [x] Baseline check: master's entrypoint fails for any non-root start
(gosu/usermod require root)
End-to-end cluster verification under restricted PodSecurity exercises
the same branch as the `--user 1000:1000` case above; the operator
repo's deploy is the natural place for that smoke test once this ships
in an image tag.
## Risks
- **Backward-compatible.** Docker Compose / root-entrypoint path is
byte-for-byte the same flow — `usermod`/`gosu` runs whenever the
container starts as root.
- **Behavior change only for previously-broken starts.** Non-root
containers used to crash; they now run. The only observable difference
for a *working* deployment is none.
- **Mismatched non-root UID/GID warns instead of failing.** Deliberate:
the remap is impossible without root, and arbitrary-UID platforms
(OpenShift) rely on group-writable volumes; a hard fail would keep them
broken. The stderr warning preserves diagnosability.
- **No new env vars, no API surface.** Pure entrypoint behavior change
gated on the runtime UID.
- **Restricted PodSecurity ready.** The non-root branch needs no Linux
capabilities — works under `drop: ALL`.
## Model Used
Claude Opus 4.6; rebase, non-root generalization, and verification
matrix by Claude Fable 5 (1M context).
## Checklist
- [x] I have searched GitHub for duplicate or related PRs and linked
them above
- [x] Thinking path traces from project context to this change
- [x] Model used specified
- [x] Checked ROADMAP.md — not in conflict with planned core work
(agent-runtime sandbox images use `tini`, no gosu — unaffected)
- [x] Tests run locally and pass (new `docker-entrypoint.test.ts`
covering all five privilege branches, plus a manual Docker matrix on the
real base image; see Verification)
- [x] No UI changes
- [x] Documented risks above
- [x] Will address all Greptile and reviewer comments before merge
Unblocks the default (non-overridden) security context of
paperclipinc/paperclip-operator#45 / #46.
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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