[a1994sc]

Description

Package definitions were generated in exactly one place - the mage-only example generator under magefiles/pkg/gen/examples/, which renders the committed examples under example/ and is reachable from nothing else - so an operator who wanted a template plus a values file per release had to fork this repository or hand-write every distro.yaml. The rendering core moves into pkg/distrogen and is shared: mage keeps its pins, tags, flavors, caches and probes, and cargoship dev render exposes the same generator against values an operator supplies.

One generator, four call sites collapsed

pkg/distrogen is Render, Write, CheckOutputs and ValidateDistro, rendering through the existing helmvalues.RenderTemplate so there is no second template engine. The four duplicated render sites in magefiles/pkg/gen/examples/ - parseExampleTemplate, writeExampleValues, writeExampleContentManifests and parseUpstreamTemplate - now call it, and the first, second and fourth are deleted. Rendering and writing stay separate steps because content.go needs the bytes first, to drop a manifest that turns out to declare nothing.

Behaviour preserved, and one behaviour changed

The example templates now render under sprig with helmvalues.FuncMap rather than bare text/template, with the digest helpers injected through a new helmvalues.WithFuncs option. generate:examples produces a byte-identical example/ tree, including main's k3s-oci flavor, which is the acceptance test for the refactor. What does change: helmvalues.RenderTemplate rejects a template that resolved a key to <no value>, so a key absent for a new tag now fails generate:exampleLine rather than rendering that literal into a file. Better behaviour, but a new failure mode on the refresh path. Separately, Write is not atomic - a mid-loop write error leaves a partial directory - while validation does gate every write.

Tests

pkg/distrogen covers output naming, injected funcs, the missing-key rejection, directory creation, schema validation, and CheckOutputs - which refuses to render a template onto itself (dev render -t ./distro.yaml with no --out overwrote the template with its own output), refuses two templates colliding on one output name, and refuses a name that would escape --out. cmd/dev_render_test.go covers writing, validation blocking the write, --no-validate, values merge order, template clobbering, and the line printed when no distro.yaml was rendered and so nothing was schema-checked. go test -short ./api/... ./cmd/... ./config/... ./internal/... ./pkg/... ./types/... and ./magefiles/pkg/gen/examples/ pass, go run ./magefiles/core generate:examples leaves example/ unchanged, prek run --all-files is clean, and mdbook build reports no warnings. mage build:binary moves the linux/amd64 binary by 8 KiB, 39.77 to 39.89 MiB, since helmvalues, pkg/schema and goccy/go-yaml were already linked.

Related Issue

Relates to N/A

Checklist before merging

• Test, docs, adr added or updated as needed

[github-actions]

Binary size

	Size
Latest release	40MB
This PR	40MB
Difference	+172KB (0.42%)