Helm Variables

External

• https://helm.sh/docs/chart_template_guide/variables/

Internal

• Helm Templates

Overview

A variable is a named reference to another built-in object or a constant. It is assigned and referred using the $<name> syntax. := is used as assignment operator.

{{- $relname := .Release.Name -}}
{{- $color := "green" -}}
...
data:
  release: {{ $relname }}

Variables are less frequently used, as an alternative preferred construct is the named template.

Variables are particularly useful in range loops. They can be used on list-like objects to capture both the index and the value:

toppings: |-
  {{- range $index, $topping := .Values.pizzaToppings }}
    {{ $index }}: {{ $topping }}
  {{- end }}

This will assign the integer index (0-based) to $index and the value to $topping. For data structures that have both key and value, range can be used to get both and assign them to variables:

{{- range $key, $val := .Values.favorite }}
{{ $key }}: {{ $val | quote }}
{{- end }}

Variable Scope

Variables are normally not "global". They are scoped to the block in which they are declared. However, there is one variable that is aways global: $. This variable will always point to the root context:

{{ $.Chart.AppVersion }}