fix: add container hardening (cap_drop, read_only, resource limits)#50
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dasirra wants to merge 8 commits into
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fix: add container hardening (cap_drop, read_only, resource limits)#50dasirra wants to merge 8 commits into
dasirra wants to merge 8 commits into
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merge: develop into main
fix: remove legacy .initialized cleanup from entrypoint
Reduces attack surface per security audit 2026-03-25 by dropping all Linux capabilities (retaining only NET_BIND_SERVICE, CHOWN, DAC_OVERRIDE), enabling read-only root filesystem with tmpfs for writable paths, enforcing no-new-privileges, and capping CPU/memory/PIDs. Closes #44
- Add SETUID and SETGID caps required by gosu for user switching - Remove NET_BIND_SERVICE (unnecessary with host networking and ports >1024) - Document reliance on Docker default seccomp profile
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Summary
Hardens the Docker container by dropping all Linux capabilities (retaining only those needed for operation), enabling a read-only root filesystem with tmpfs for writable paths, enforcing no-new-privileges, and capping CPU/memory/PID usage. This reduces the attack surface and prevents a compromised process from consuming host resources.
Source
Closes #44
What Changed
docker-compose.yaml:
cap_drop: ALL— drops all capabilities by defaultcap_add: CHOWN, DAC_OVERRIDE, SETUID, SETGID— retains only what is needed (CHOWN/DAC_OVERRIDE for filesystem ops, SETUID/SETGID for gosu user switching in entrypoint)security_opt: no-new-privileges:true— prevents privilege escalation via setuid binariesread_only: true— root filesystem is read-onlytmpfs: /tmp, /run, /var/tmp— in-memory writable paths (covers Node compile cache at/var/tmp)deploy.resources.limits: cpus=2, memory=4G— prevents resource exhaustionpids_limit: 512— caps process countTasks
Code Review
SETUID/SETGIDcapabilities required bygosufor user switching in entrypoint; without these the container would fail to startNET_BIND_SERVICE(unnecessary withnetwork_mode: hostand ports >1024); added comment documenting Docker default seccomp profileBuilt autonomously by
/build