fix(sandbox): undo tmpfs overlay when setns fails during SPIFFE mount namespace setup#2184
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… namespace setup On OpenShift and other container runtimes that do not grant CAP_SYS_ADMIN, setns(CLONE_NEWNS) fails with EPERM after create_supervisor_identity_mount_namespace has already mounted an empty tmpfs over the SPIFFE workload API socket directory. PID 1 remains stuck in the new mount namespace where the tmpfs hides the socket, making it invisible to all processes. Fix: when setns() fails, call umount2(MNT_DETACH) to remove the tmpfs overlay before returning the error, so the SPIFFE socket stays accessible even without namespace isolation. Also wire up prepare_supervisor_identity_mount_namespace_from_env in main.rs and make it gracefully degrade on error instead of aborting the supervisor. Signed-off-by: Adel Zaalouk <azaalouk@redhat.com>
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/ok to test bec39d9 |
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Summary
setns(CLONE_NEWNS)fails withEPERM(common on OpenShift and hardened K8s withoutCAP_SYS_ADMIN),create_supervisor_identity_mount_namespaceleaves an empty tmpfs mounted over the SPIFFE workload API socket directory. Since PID 1 is stuck in the new mount namespace, the socket becomes invisible to all processes in the container, even though the CSI volume is healthy.umount2(MNT_DETACH)in thesetns()error path to remove the tmpfs overlay before returning, keeping the SPIFFE socket accessible.prepare_supervisor_identity_mount_namespace_from_envcall inmain.rsand makes it gracefully degrade (warn + continue) instead of aborting the supervisor on error.Related Issue
N/A (discovered during SPIFFE + token grant integration testing on OpenShift)
Changes
crates/openshell-supervisor-process/src/process.rs:create_supervisor_identity_mount_namespace: onsetns()failure,umount2(target, MNT_DETACH)before returning errorprepare_supervisor_identity_mount_namespace_from_env: catch errors, log warning, set namespace toNone, continuecrates/openshell-sandbox/src/main.rs: callprepare_supervisor_identity_mount_namespace_from_env()before tracing setupTesting
/spiffe-workload-api/spire-agent.sockis visible inside sandbox containercargo test --workspace)Checklist
cargo fmtcleancargo clippyclean