Steady at the helm

"Learning is fun" is what tell myself each time I probe k8s. This time I decided to dig into Helm. Helm is a package manager for Kubernetes. That just means we can write our k8s services in code similar to Terrafrom.

Helm is like a template processor. It consists of yaml files with two types of files: Chart.yaml and values.yaml. The chart file contains keys and templated values such as these:

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tree: {{ .Value.treeType }}

Helm is used to keep infrastructure as code, allowing for quick deploys and rollbacks to the cluster.

Setup

Here's a quick run through of how to get started. Create a project first

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helm create <project name>

Add some values to the values.yaml file:

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favorite:
  drink: grog

Add a ConfigMap template in templates/configmap.yaml:

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apiVersion: v1
kind: ConfigMap
metadata:
    name: {{ .Release.Name }}-configmap-{{ .Release.Namespace }}
data:
    drink: {{ .Values.favorite.drink | quote }}

Note the .Release object. Helm has a few built-in objects. Note also the pipe to a built-in function quote which will quote the drink value.

Now get a dry-run output first to see the compute value:

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helm install <release name> . --debug --dry-run

...
COMPUTED VALUES:
favorite:
  drink: grog
...
MANIFEST:
---
# Source: ./templates/configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
    name: <release name>-configmap-default
data:
    drink: "grog"

Congrats on getting up and running with helm.

Anyone can hold the helm when the seas are calm - Publius Syrus