The Double-Brace Action Syntax

Whatever sits between the braces is called an action. Helm evaluates it at render time and drops the result back into your YAML.

The simplest action just prints something. Here Helm replaces the action with the release name before the manifest is applied.

That leading dot is the context: the top-level object holding everything Helm knows. You walk into it with more dots, like .Release.Name.

Spaces inside the braces are just style. {{ .Chart.Name }} and {{.Chart.Name}} render the same. Helm convention favors the padded form for readability.

An action that yields a value is an expression action. It substitutes text right where it sits, perfect for names, tags, and labels.

Other actions do not print at all. Keywords like if and range steer what renders, deciding whether a block appears or repeats.

This whole syntax comes from Go's text/template engine. Helm layers extra functions on top, but the {{ }} foundation is pure Go.

Text outside the braces is passed through untouched. Only the actions get evaluated, so your YAML structure survives rendering intact. 🧱

Run helm template and watch each action vanish, replaced by its computed value. That output is exactly what reaches Kubernetes.

You now know the core syntax: {{ }} marks an action, the dot is the root context, and everything outside the braces renders unchanged. 🎯