Search⌘ K
Home
Courses
A Practical Guide to Helm

The Helm Diff Plug-In

Explore how to utilize the Helm Diff plugin to test and visualize modifications in Helm chart deployments. Learn to run diff upgrade commands to see changes before applying them and compare different release revisions to ensure quality in your Kubernetes applications.

We'll cover the following...

The helm diff upgrade command

The help diff upgrade command is the most widely used command when we’re developing a chart. It allows us to test how our changes will affect the existing Helm release.

Let’s say that we would like to add a new annotation to all Kubernetes resources. As we may remember, it was declared in the _helpers.tpl file, therefore, we just need to add a new line there, called app.fullName (remove lines 16 and 18 from the same file in the playground located at the end of this lesson). :

Go (1.16.5)
{{/*
Generic labels for each Kubernetes resource
*/}}
{{- define "app.labels" -}}
app.kubernetes.io/name: {{ include "app.fullName" . }}
app.kubernetes.io/version: {{ .Release.Name }}-{{ .Release.Revision }}
app: {{ include "app.fullName" . }}
group: {{ .Values.app.group }}
app.fullName: {{ include "app.fullName" . }}
{{- end }}

To find out how this change will affect our currently active Helm release we only need to run the helm diff upgrade command followed by the namespace and chart names. ...