Part 3 — Delivering artifacts from a Sandcastle
Part 3 will focus on what happens after the Sandcastle finishes: how the durable Git artifacts it produced are validated, delivered, and picked up by the surrounding Open Engineering pipelines.
The intended learning arc is:
- Compare the Sandcastle’s inner iteration loop (agent → repo/branch → commits) with the outer delivery loop (branch → PR → merge → GitOps → Crossplane reconciliation).
- Discuss when a Sandcastle should produce a branch, a pull request, or a release artifact, and how each choice interacts with the Pico runtime and Crossplane composition layers.
- Layer additional guardrails: automated verification, review, and policy checks that run against the branch the Sandcastle hands back — outside the Sandcastle’s own boundary.
Lessons
- 01 Handing off to Kubernetes — the first runnable Part 3 lesson. Teaches the concrete construct → compose boundary: how the durable Git branch the Hello World Pico Sandcastle lab produced is promoted into a Crossplane Composite Resource the Hello Pico on Kubernetes lab already knows how to compose. Ships with a runnable Sandcastle → Kubernetes hand-off lab.
- 02 The outer delivery loop — picks up where the hand-off ends. Teaches the four outer-loop stages — review / PR, merge, GitOps delivery, and downstream Crossplane reconciliation — and the three guardrails (automated verification, review, policy) that surround them, all outside the Sandcastle boundary. Ships with a runnable Outer delivery loop lab that drives stages 1–2 against live GitHub without a cluster and stages 3–4 against a Crossplane cluster when one is reachable.
Additional Part 3 lesson content will follow the same lesson layout as Part 1 and the Pico Introduction lesson.
Both current Part 3 lessons ship runnable labs. Lesson 01 (Handing off to Kubernetes) is runnable via the Sandcastle → Kubernetes hand-off lab. Lesson 02 (The outer delivery loop) is runnable via the Outer delivery loop lab, which drives real GitHub PR/merge and reconciles the merged XR onto the cluster from Hello Pico on Kubernetes. The outer-loop lab is honest about its hosted prerequisites (a learner-controlled GitHub env repo + authenticated gh CLI, plus a Crossplane cluster and optionally flux for stages 3–4). Further Part 3 lessons on multi-artifact hand-offs and multi-environment promotion remain intentionally scaffolded for a later curriculum wave.