Convert a YAML to string in Helm

问题

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Be able to use YAML and not string in values and use tpl to replace variables in the ConfigMap

I have an helm chart used to deploy an application that have configuration file in YAML format. Currently, my helm chart use the following code:

values.yaml

databaseUser: "dbuser"

configFiles:
  db_config_file.yaml: |-
    databaseUser: {{ .Values.databaseUser }}
    databasePort: 1234
    [...]

[...]

templates/configmap.yaml

data:
  {{- range $name, $config := .Values.configFiles }}
  {{ $name }}: |-
{{ tpl $config $ | indent 4 }}
  {{- end }}

This code allow me to change easily the databaseUser from values, but the problem is that if I want to change the value of databasePort, I have to rewrite the entire configuration like that:

configFiles:
  db_config_file.yaml: |-
    databaseUser: {{ .Values.databaseUser }}
    databasePort: 9876

which is inconvenient. It works like that because the db_config_file.yaml content is interpreted as string because I give it to the tpl function which only accept strings.

So my question is, is there a way to convert the YAML to string in a Helm template and get the following things:

databaseUser: "dbuser"

configFiles:
  db_config_file.yaml: # Content is not a string block
    databaseUser: {{ .Values.databaseUser }}
    databasePort: 1234
    [...]

[...]

data:
  {{- range $name, $config := .Values.configFiles }}
  {{ $name }}: |-
{{ tpl (<a toString function> $config) $ | indent 4 }}
  {{- end }}

回答1:

as your question helped me to solve mine, maybe I can help you with my little knowledge. The official helm documentation describes a way to enforce type inference:

coffee: "yes, please"
age: !!str 21
port: !!int "80"

HTH, Martin

回答2:

Did you consider templating databasePort as well and wrapping your values in double quotes?

values.yaml

databaseUser: "dbuser"
databasePort: 1234

configFiles:
  db_config_file.yaml: |-
    databaseUser: "{{ .Values.databaseUser }}"
    databasePort: "{{ .Values.databasePort }}"

来源：https://stackoverflow.com/questions/62432632/convert-a-yaml-to-string-in-helm