Documentation

Kubernetes is the boundary.

Sceptre targets conformant Kubernetes APIs. A local distribution is an installation profile, not an application runtime dependency.

The API never creates clusters, enables add-ons, imports images, runs port-forwards, or invokes distribution-specific CLIs.

Layer boundaries

Application

FastAPI, React, training, analysis, inference, and data-service clients.

Workload

Namespace-scoped Jobs, Deployments, Services, logs, status, and optional Ingresses.

Capability

Optional quotas, metrics, GPUs, ingress, PriorityClass, and shared-cache discovery.

Packaging

One generic Helm chart with thin image-distribution and accelerator profiles.

Scheduling and permissions

Helm supplies resource requests and limits. Kubernetes remains the final admission and node-selection authority. The default API Role is limited to its release namespace, and no ClusterRole is installed by default.

Capabilities degrade safely

No Metrics Server

Jobs, logs, and status continue; live CPU and RAM are unavailable.

No GPU device plugin

GPU is not selected; CPU remains available.

No ingress controller

ClusterIP and kubectl port-forward remain available.

No shared RWX storage

Per-pod cache is used and the S3-compatible object store remains authoritative.

Storage and exposure

Bundled PostgreSQL, SeaweedFS, and MLflow use independently configurable claims and can be replaced by approved external services. Services begin as ClusterIP. External model URLs appear only after configured exposure is admitted.

Read the complete portability contract for the acceptance matrix and lifecycle details.