Files
Seth Jennings 6461677c32 feat(policy): accept numeric UIDs for sandbox process identity (#1973)
* feat(policy): accept numeric UIDs in sandbox process identity validation

Allow run_as_user and run_as_group to be either the literal 'sandbox'
or a numeric UID/GID within [1000, 2_000_000_000]. This removes the
hard dependency on a baked-in 'sandbox' user in container images,
enabling compute drivers to inject resolved UIDs at sandbox creation.

Phase 1 of #1959.

Signed-off-by: Seth Jennings <sjenning@redhat.com>

* feat(supervisor): accept numeric UIDs for process identity dropping

Allow run_as_user and run_as_group to be numeric UIDs/GIDs, removing
the hard dependency on a baked-in 'sandbox' user in container images.

Changes:
- validate_sandbox_user(): accepts numeric UIDs without passwd lookup
  (logs OCSF event); keeps passwd check for "sandbox" name; rejects
  non-numeric non-sandbox strings that fail passwd lookup
- prepare_filesystem(): passes numeric UIDs/GIDs directly to chown()
  instead of requiring a passwd entry
- drop_privileges(): resolves numeric UIDs/GIDs directly via UID::from_raw
  / Gid::from_raw; skips initgroups when target uid matches current euid;
  uses guard conditions before setgid/setuid calls
- session_user_and_home(): falls back to ("{uid}", "/sandbox") for
  numeric UIDs, avoiding a passwd lookup that will fail

Re-exports MIN_SANDBOX_UID and MAX_SANDBOX_UID from openshell-policy
so callers have consistent range constants.

Phase 2 of #1959.

Signed-off-by: Seth Jennings <sjenning@redhat.com>

* feat(driver-kubernetes): resolve sandbox UID/GID from config or OpenShift SCC annotations

Phase 3 of the numeric-UID plan: allow operators to specify explicit
sandbox_uid/sandbox_gid in Kubernetes driver config, auto-detect from
OpenShift SCC namespace annotations, and propagate resolved values to
supervisor container env vars and PVC init container securityContext.

Changes:
- Add sandbox_uid/sandbox_gid fields to KubernetesComputeConfig
- Add SANDBOX_UID/SANDBOX_GID env var constants to openshell-core
- Implement resolve_sandbox_identity() to fetch namespace annotations
  and auto-detect OpenShift SCC UID ranges (sa.scc.uid-range)
- Pass resolved UID/GID through SandboxPodParams to pod spec builder
- Inject SANDBOX_UID/SANDBOX_GID env vars into supervisor container
- Update PVC init container securityContext with resolved UID/GID
  instead of hard-coded root
- Add comprehensive unit tests for resolution logic and annotation
  parsing (resolve_sandbox_uid, resolve_sandbox_gid, OpenShift SCC
  annotation parsing)

Signed-off-by: Seth Jennings <sjenning@redhat.com>

* feat(driver-vm): add configurable sandbox UID/GID and update docs/examples

Phase 4 of the numeric-UID plan: replace hardcoded SANDBOX_UID (10001)
in VM rootfs preparation with configurable sandbox_uid/sandbox_gid fields.

Changes:
- Add sandbox_uid/sandbox_gid to VmDriverConfig with serde derives
- Pass resolved UID/GID through prepare_sandbox_rootfs_from_image_root
  to ensure_sandbox_guest_user which writes /etc/passwd/group/gshadow
- Update BYOC Dockerfile: remove groupadd/useradd, document runtime UID
  injection and the ability to skip baked-in sandbox user
- Update gateway-config.mdx: document sandbox_uid/sandbox_gid for both
  Kubernetes (with OpenShift SCC autodetection) and VM drivers
- Update sandbox-compute-drivers.mdx: add Sandbox User Identity section
  explaining numeric UID support across all compute drivers
- Update rootfs tests to use non-default UIDs, verify config passthrough

Signed-off-by: Seth Jennings <sjenning@redhat.com>

* code review changes

* fix(supervisor): harden tests for restricted CI container environments

Guard tests against CI-specific constraints: root without CAP_SETPCAP,
UIDs with no /etc/passwd entry, and restricted /proc access.

Signed-off-by: Seth Jennings <sjennings@nvidia.com>
Signed-off-by: Seth Jennings <sjenning@redhat.com>

---------

Signed-off-by: Seth Jennings <sjenning@redhat.com>
Signed-off-by: Seth Jennings <sjennings@nvidia.com>
2026-07-02 13:31:06 -07:00
..

openshell-driver-kubernetes

Kubernetes-backed compute driver for OpenShell cluster deployments.

The driver uses the Kubernetes API to create, delete, fetch, and watch sandbox custom resources in the configured namespace. It runs in-process with the gateway server.

Runtime Model

The gateway stores platform state and delegates sandbox workload creation to this driver. Kubernetes owns scheduling and pod lifecycle. The openshell-sandbox supervisor inside each workload owns agent isolation, credential injection, policy polling, logs, and the gateway relay.

Sandbox Resource

The driver works with the agents.x-k8s.io Sandbox custom resource. It detects the served Sandbox API at runtime, caches the selected API version for the gateway process, and uses v1beta1 when available before falling back to v1alpha1. Restart the gateway after an in-place Agent Sandbox upgrade so the driver can detect served API versions again. Driver events map Kubernetes object state and platform events into the shared compute-driver protobuf surface used by the gateway.

Kubernetes API calls use explicit timeouts so gRPC handlers do not block indefinitely when the API server is slow or unavailable.

Workspace Persistence

Sandbox pods use a PVC-backed /sandbox workspace. An init container seeds the PVC from the image's original /sandbox contents on first start and writes a sentinel so subsequent starts skip the copy.

This is a stopgap persistence model. It preserves user files across pod rescheduling but duplicates the base workspace and does not automatically apply image updates to existing PVCs. Future snapshotting should replace it.

Credentials, TLS, and Relay

The driver injects gateway callback configuration, sandbox identity, TLS client material, and the supervisor SSH socket path into the workload. Driver-owned values must override image-provided environment variables.

Sandbox pods run as service_account_name and keep automountServiceAccountToken: false. The only Kubernetes token exposed to the supervisor is an explicit, audience-bound projected token mounted at /var/run/secrets/openshell/token for the one-shot IssueSandboxToken bootstrap exchange.

The gateway uses the supervisor relay for connect, exec, and file sync. Sandbox pods do not need direct external ingress for SSH.

Container Security Context

The driver grants the sandbox agent container the Linux capabilities the supervisor needs for namespace setup and policy enforcement. It can also request a Kubernetes AppArmor profile through app_armor_profile.

Supported values are Unconfined, RuntimeDefault, and Localhost/<profile-name>. An empty or unset value omits securityContext.appArmorProfile. Helm deployments default sandbox agent containers to Unconfined because runtime/default AppArmor profiles can block the supervisor's network namespace mount setup on AppArmor-enabled nodes.

GPU Support

When a sandbox requests GPU support, the driver checks node allocatable capacity for nvidia.com/gpu and requests the configured GPU count in the workload spec. When no count is set, the driver requests one GPU resource. The sandbox image must provide the user-space libraries needed by the agent workload.

Driver Config POC

The RFC 0005 POC accepts the selected SandboxTemplate.driver_config.kubernetes block as DriverSandboxTemplate.driver_config. The Kubernetes driver owns the nested schema and currently accepts:

  • pod.node_selector
  • pod.tolerations
  • pod.runtime_class_name
  • pod.priority_class_name
  • containers.agent.resources.requests
  • containers.agent.resources.limits

Nested keys inside the kubernetes block use snake_case. The top-level driver_config envelope is keyed by driver names, so kubernetes is not part of the nested schema.

Set this through the CLI with the public driver-keyed envelope. The gateway forwards only the kubernetes object to this driver:

openshell sandbox create \
  --driver-config-json '{"kubernetes":{"pod":{"runtime_class_name":"kata-containers","node_selector":{"pool":"gpu"}}}}' \
  -- claude

Resource keys use native Kubernetes resource names and quantity strings. The POC parser renders the keys listed above and rejects unknown fields. pod.runtime_class_name maps to PodSpec runtimeClassName and overrides the driver's configured default_runtime_class_name; the typed public SandboxTemplate.runtime_class_name still takes precedence when set. Use the public --gpu flag for the default GPU request, pass a count to --gpu for counted GPU requests, and use driver_config only for additional driver-owned resource details.