Helm Templates
External
- The Chart Template Developer’s Guide https://helm.sh/docs/chart_template_guide/#the-chart-template-developer-s-guide
Internal
Overview
Templates are files living under a chart's templates/ directory. They are written in YAML with Helm templates extensions. Upon processing by Helm, they become Kubernetes manifest files. Helm template extensions are written in the Help template language, which is based on Go templates.
The templates/ Directory
The 'templates' directory contains templates that, after combination with values, will generated Kubernetes manifest files. Files whose names start with "_" or "." will be ignored. - Really? helm install complained about _pod.yaml.
Built-in Objects
Chart
Exposes all contents of Chart.yaml. An existing field is available as (note leading dot) .Chart.<UpperCasedFirstLetterFieldName>.
Example:
{{ .Chart.Name }}
{{ .Chart.Version }}
Values
Release
Release.Name
Exposes the release name:
{{ .Release.Name }}
Release.Revision
Exposes the release revision:
{{ .Release.Revision }}
Release.Time
Exposes the time of the release:
{{ .Release.Time }}
Release.Namespace
Exposes the namespace to be released info, if the manifest does not override:
{{ .Release.Namespace }}
Release.IsUpgrade
This is set to true if the current operation is an upgrade or rollback.
{{ .Release.IsUpgrade }}
Release.IsInstall
This is set to true if the current operation is an install.
{{ .Release.IsInstall }}
Release.Service
Exposes the releasing service - always Tiller
Files
Capabilities
Template
TODO
Template Comments
# This is a comment
{{- /*
This is another comment
*/ -}}
TODO
- https://helm.sh/docs/chart_template_guide/#the-chart-template-developer-s-guide
- https://helm.sh/docs/chart_best_practices/#templates
- https://helm.sh/docs/developing_charts/#templates-and-values
- https://helm.sh/docs/developing_charts/#know-your-template-functions
- https://helm.sh/docs/developing_charts/#quote-strings-don-t-quote-integers
- https://helm.sh/docs/developing_charts/#using-the-include-function
- https://helm.sh/docs/developing_charts/#using-the-required-function
- https://helm.sh/docs/developing_charts/#using-the-tpl-function
- https://helm.sh/docs/developing_charts/#creating-image-pull-secrets
- https://helm.sh/docs/developing_charts/#automatically-roll-deployments-when-configmaps-or-secrets-change
- https://helm.sh/docs/developing_charts/#tell-tiller-not-to-delete-a-resource
- https://helm.sh/docs/developing_charts/#using-partials-and-template-includes
- https://helm.sh/docs/chart_best_practices/#pods-and-podtemplates
- https://helm.sh/docs/chart_best_practices/#images
- https://helm.sh/docs/chart_best_practices/#imagepullpolicy
- https://helm.sh/docs/chart_best_practices/#podtemplates-should-declare-selectors