Helm Template If/Else
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External
Internal
Overview
if/else can be used to create conditional blocks.
The if control structures evaluate pipelines, not just values (values are a special case of a pipeline):
{{ if PIPELINE }}
# Do something
{{ else if OTHER_PIPELINE }}
# Do something else
{{ else }}
# Default case
{{ end }}
A pipeline evaluates to false if the result of the pipeline, or the value, is:
- a boolean false
- a numeric zero
- an empty string
- a
nil(empty or null) - an empty collection (map, slice, tuple, dict, array).
In any other case, the condition is evaluated to true.
Example:
{{ if .Values.debug }}
# Do something
{{ else }}
# Do something else
{{ end }}
Expression
if expressions are built with functions: eq, ne, lt, gt, and, or, so the function name is provided first, followed by the arguments. Functions can be grouped with ( ).
Testing the Existence of Two Configuration Elements in the Same Expression
{{- if or .Values.myApp.config.local .Values.myApp.config.nfs }}
...
{{- end }}
Testing the Non-Existence of a Configuration Element
The following conditional evaluates to true and the embedded content is rendered if the configuration element does NOT exist:
{{- if not .Values.myApp.something }}
...
{{- end }}
Testing Equality and Inequality of Values
{{- if eq .Values.myApp.color "blue" }}
...
{{- end }}
{{- if ne .Values.myApp.color "blue" }}
...
{{- end }}
{{- if eq .Values.myApp.something .Values.myApp.somethingElse }}
...
{{- end }}
{{- if and (eq .Values.myApp.color "blue") (eq .Values.myApp.shape "square") }}
...
{{- end }}