I can not find a way to just iterate over a simple range, 10 -> 20 using helm templating.
{{range 10 until 20 }}
- port: {{ . }}
targetPort: {{ . }}
protocol: TCP
name: brick-{{ . }}
{{end}}Helm uses the standard Go text/template system for rendering templates, plus (most of) the Sprig extension library, plus a couple more things. In particular, Sprig includes until and untilStep functions to generate lists of numbers, which you can then range over. So you should be able to:
{{- range untilStep 10 20 1 }}
- port: {{ . }}
...
{{- end }}