Helm template check if boolean value is actually empty not false

Question

How to tell if a value, more specifically a boolean typed value is empty in a gotpl alias helm template?

How to tell if a simple value is empty?

Answer 1

You have multiple options, how to tell if a normal (not boolean) value is empty.

A very brute force and quite long way is to put an if statement around your node such as

{{ if .Values.simpleText }}
isEmpty: false
{{ end }}

This will evaulate isEmpty as false only if there is any value inside .Values.simpleText

A better way to do this is to use the inbuilt empty function:

isEmpty2: {{ empty .Values.simpleText }}

This does the same as the first example just shorter and arguably more readable

The issue with theese methods is that if you have a node which is a bool theese methods wont work.

#values.yaml
myBool: false
#-----------------------------------------
#template.yaml
isBoolEmpty: {{ empty .Values.myBool }}
#-----------------------------------------
#output
isBoolEmpty: true

This will claim that .Values.myBool is empty even tho it clearly has a value which is false.

Now there is an option to check if a value is nil

isNil: {{ eq nil .Values.nilValue }}

This will result as true if the value is indeed nil ( nilValue: ) but as soon as you have a value inside nilValue you will get a type exception.

The solution that I found and seemed the easiest to understand and to use is:

{{ if (quote .Values.myBool | empty)  }}
isActuallyEmpty: ".Values.myBool is empty"
{{ else }}
isActuallyEmpty: ".Values.myBool has a false or true value"
{{ end }}

I am sorry if this is very trivial but I know that I was struggleing with this question for some time.