Helm Macro - toYamlPretty - A recursive YAML formatter

_helpers.tpl

{{- define "toPrettyYaml" -}}
  {{- $out := "" -}}
  {{- range $k, $v := . -}}
    {{- if not (empty $v) -}}

      {{- /* Walk any maps */ -}}
      {{- if kindIs "map" $v -}}
        {{- $out = (print $out
            $k ":\n"
            (include "toPrettyYaml" $v | indent 2)
            "\n"
          )
        -}}

      {{- /* Iterate any slices */ -}}
      {{- else if kindIs "slice" $v -}}
        {{- $out = (print $out $k ":\n") -}}
        {{- range $_, $v := $v -}}
          {{- $out = (print $out
              "  -\n"
              (include "toPrettyYaml" $v | indent 4)
              "\n"
            )
          -}}
        {{- end -}}

      {{- /* Quote any strings */ -}}
      {{- else if kindIs "string" $v -}}
        {{- if contains "\n" $v -}}
          {{- if hasSuffix "\n" $v -}}
            {{- if eq 1 (len (splitList "\n" $v|compact)) -}}
              {{- $out = printf "%s%s: >\n%s\n" $out $k (wrap 80 $v|trimSuffix "\n"|indent 2) -}}
            {{- else -}}
              {{- $out = printf "%s%s: |\n%s\n" $out $k ($v|trimSuffix "\n"|indent 2) -}}
            {{- end -}}
          {{- else -}}
            {{- $out = printf "%s%s: |-\n%s\n" $out $k ($v|indent 2) -}}
          {{- end -}}
        {{- else -}}
          {{- if gt (len $v) 80 -}}
            {{- $out = printf "%s%s: >-\n%s\n" $out $k (wrap 80 $v|indent 2) -}}
          {{- else -}}
            {{- $out = printf "%s%s: %q\n" $out $k $v -}}
          {{- end -}}
        {{- end -}}

      {{- /* Print anything else, as it is */ -}}
      {{- else -}}
        {{- $out = (print $out
            $k ": " $v
            "\n"
          )
        -}}

      {{- end -}}
    {{- end -}}
  {{- end -}}

  {{- /*
    Chop of the trailing newline so callers don't have to treat
    this macro as special and can use `nindent` as usual.
  */ -}}
  {{- $out | trimSuffix "\n" -}}
{{- end -}}