[braghettos]

A LocalResource that asks to copy bytes does not get its bytes copied

copier.WithGoTemplate(values) is installed unconditionally, so every file goes through text/template + sprig — including when placeholdersToOverride is absent and values is nil. Rendering is not a no-op on content that merely looks like a template.

Found on krateo-057. LocalResource/publish-sock-shop-003, publishing a Helm chart through the Blueprint Builder, is stuck at:

create failed: unable to copy files:
template: template:61: function "toYaml" not defined

toYaml is a Helm builtin, not a sprig one — as are include, required and tpl. So a Helm chart template can never be committed verbatim through this path, which is exactly what the Blueprint Builder exists to do. That CR sets no placeholders at all.

The loud failure is the lucky half

A template that merely parses is executed against an empty value set. The added test asserts this rather than describing it:

"replicas: {{ .Values.replicas }}\n"  ->  "replicas: <no value>\n"

That gets committed. A corrupted chart that still looks like a chart, no error anywhere, and nothing downstream able to tell. The toYaml crash is the case that at least announces itself.

The fix

Install the templating pass only when there are values — which is what the sibling repo controller already does:

// internal/controllers/repo/repo.go
if values != nil {
    ...
    opts = append(opts, copier.WithGoTemplate(tplVals))
}

The two controllers simply disagreed about this. Behaviour when placeholders are present is unchanged.

opts := []copier.Option{
    copier.WithOriginCopyPath(fromPath),
    copier.WithTargetCopyPath(toPath),
}
if len(values) > 0 {
    opts = append(opts, copier.WithGoTemplate(values))
}
co, err := copier.NewCopier(fromLocal, toRepo.FS(), opts...)

Tests

internal/tools/copier/helm_verbatim_test.go — four cases, all passing:

test	pins
TestCopyLeavesHelmTemplateVerbatimWhenNotTemplating	a Helm chart survives byte-for-byte with no pass installed
TestGoTemplatePassRejectsHelmBuiltins	with the pass, it fails with the exact krateo-057 error string
TestGoTemplatePassSilentlyEmptiesUnknownValues	the silent case — {{ .Values.replicas }} → <no value>
TestPlaceholdersStillSubstituteWhenPresent	substitution still works when the CR asks for it

go build ./..., go vet and go test ./internal/... clean — 7 packages ok.

Scope

No API, CRD or chart change. A LocalResource wanting substitution keeps declaring placeholdersToOverride; one that does not now gets what it asked for. No change is needed in builder-publish — it already sets no placeholders.

Giving LocalResource a choice of engine (repo has the krateo.io/templating-engine annotation, localresource does not) is a reasonable follow-up, but is not needed to unblock this and is deliberately not in scope here.

Related: #5 / #6 (the bearer/usernameRef connect failure) — that one blocked all twelve LocalResources at connect; with it fixed via the chart side, eleven of twelve now sync and this is the last one standing.

🤖 Generated with Claude Code

https://claude.ai/code/session_01JumEqTGGJ2hf3vjE3xFQsv

[braghettos]

---

Update — the annotation, after review feedback

The first commit inferred intent from placeholdersToOverride being empty. That inference is not always right, and the objection is correct: git-provider templates whatever file it is given, not only Helm manifests. A file can legitimately template with no inputs at all. Measured against the real copier:

file	before this PR	first commit alone	now, with gotemplate
README.md — {{ now | date "2006-01-02" }}	2026-09-10	❌ literal	✅ 2026-09-10
config.json — {{ uuidv4 }}	a UUID	❌ literal	✅ a UUID
Makefile — {{ env "USER" }}	the user	❌ literal	✅ the user
main.tf — {{ randAlphaNum 6 | lower }}	riqdly	❌ literal	✅ rendered

So the CR can now say what it means, using the annotation the repo controller has carried all along:

krateo.io/templating-engine	behaviour
(absent — default)	render only if placeholdersToOverride is set
gotemplate	always render, including with no placeholders
none	never render, even with placeholders declared

Anything else is rejected with an error naming the value, rather than silently treated as one of the above.

The default is unchanged and still fixes the Helm case. gotemplate restores value-free rendering for anyone relying on it. none states verbatim intent explicitly and keeps holding if placeholders are added later.

One definition of the annotation

The string now lives once, in a new internal/controllers/common/templating package, referenced by both controllers; repo.AnnotationTemplatingEngine stays as a deprecated alias.

That is deliberate. These two controllers have now shipped three defects by disagreeing about a shared rule — which auth methods consume a username (#5/#6), when to install a templating pass (this), and whether a failed ConfigMap load aborts a sync (#9). A shared constant is small, but it is the seam where two of them started.

Tests

Six cases, exercising the real copier so they assert what lands in the target repo:

case	expected
default + no values	verbatim (the sock-shop case)
default + values	substituted (unchanged)
gotemplate + no values	{{ "x" | upper }} → X
none + values declared	still verbatim
unknown engine	error naming the value
gotemplate + Helm builtin	still fails — the annotation is a choice, not a promise that Helm syntax survives a Go render

docs/local-resource.md documents all three modes and spells out the Helm failure modes: toYaml/include fail; {{ .Values.x }} silently becomes <no value>; {{/* */}} headers are deleted.

go build ./..., go vet, go test ./internal/... clean — 8 packages ok.