Building your own Helm Charts
If you have not installed helm yet, do so by using
curl https://raw.githubusercontent.com/helm/helm/master/scripts/get-helm-3 | bash
helm
Part I - Generating a Chart with One Service
Create a namespace and switch to it
kubectl create namespace dev
kubectl config set-context --current --namespace=dev
kubectl config get-contexts
Generate a helm chart scaffold and change into the directory created to create a copy of values.yaml
cd ~
mkdir instavote
cd instavote/
helm create vote
cd vote/
Edit values.yaml to update replicaCount, image and tag as
replicaCount: 2
image:
repository: schoolofdevops/vote
pullPolicy: IfNotPresent
# Overrides the image tag whose default is the chart appVersion.
tag: "v5"
Update service type to Node Port
service:
type: NodePort
port: 80
nodePort: 30300
Also update the service.yaml template with the additional property for nodePort defined as ,
File : service.yaml
apiVersion: v1
kind: Service
metadata:
name: vote
labels:
{{- include "instavote.labels" . | nindent 4 }}
spec:
type: {{ .Values.service.type }}
ports:
- port: {{ .Values.service.port }}
targetPort: http
protocol: TCP
name: http
nodePort: {{ .Values.service.nodePort }}
selector:
{{- include "instavote.selectorLabels" . | nindent 4 }}
Install this chart with helm to deploy the vote service as:
helm install -n dev vote . --dry-run
helm install -n dev vote .
Validate with
helm list -A
kubectl get all
Setting up Multi Environemnt Deployment with HELM
Copy over the values.yaml file to values.staging.yaml
cp values.yaml values.staging.yaml
Update the properties in values.staging.yaml as,
replicaCount: 4
image:
repository: schoolofdevops/vote
pullPolicy: IfNotPresent
# Overrides the image tag whose default is the chart appVersion.
tag: "v4"
Update service type to Node Port
service:
type: NodePort
port: 80
nodePort: 30400
Create a namespace for staging as
kubectl create namespace staging
Install this chart with helm to deploy the vote service as:
helm install -n staging vote --values=values.staging.yaml . --dry-run
helm install -n staging vote --values=values.staging.yaml .
Validate with
helm list -A
kubectl get all -n staging
Part III : Overriding Values, Rollbacks
Lets learn how to override values from the command line. To do so, lets add one property
File : templates/deployment.yaml
containers:
- name: vote
env:
- name: OPTION_A
value: {{ .Values.options.A }}
- name: OPTION_B
value: {{ .Values.options.B }}
This will read from values file and set those as environmnt variables. Lets set the default values.
File: values.yaml
replicaCount: 2
options:
A: MacOS
B: Windows
now upgrade the release as
helm upgrade -n dev vote .
validate
helm list -A
kubectl get all -n dev
Check the application to see the default values being visible.
You could override the values from the command line as
helm upgrade -n dev vote --set options.A=Green --set options.B=Yellow .
check the web app now
try one more time, this time with a description
helm upgrade -n dev vote --set options.A=Orange --set options.B=Blue . --description "Overriding values to Orage and Blue form CLI"
you should see the values change every time.
Check the release now
helm list -A
[sample output]
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
vote dev 4 2025-04-20 03:42:44.279388435 +0000 UTC deployed vote-0.1.0 1.16.0
vote staging 1 2025-04-20 03:34:03.00413779 +0000 UTC deployed vote-0.1.0 1.16.0
You could also examine the history of the release as
helm history -n dev vote
try rolling back a version
e.g.
helm rollback vote
you could also go back to a specific version using the revision number as
helm rollback vote xx
where replace xx with the revision number you wish to roll back to.
Adding Redis Service
Lets add a second service by creating a new chart structure, where we will have our main chart for application and a subchart for vote and redis.
# switch back to instavote directory
cd instavote
helm create redis
cd redis
Edit values.yaml to update the image and tag as
image:
repository: redis
pullPolicy: IfNotPresent
tag: "alpine"
also update the service port as
service:
type: ClusterIP
port: 6379
Now lets create the main chart for instavote app to include the redis and vote as subcharts
# switch back to instavote directory
cd instavote
mkdir main
cd main
Add Chart.yaml and values.yaml files as
File : Chart.yaml
apiVersion: v2
name: instavote
description: A Helm chart for Kubernetes
type: application
version: 1.0.0
appVersion: "1.0.0"
dependencies:
- alias: vote
name: vote
version: "0.1.0"
repository: file://../vote
- alias: redis
name: redis
version: "0.1.0"
repository: file://../redis
File : values.dev.yaml
vote:
repicaCount: 3
image:
repository: "schoolofdevops/vote"
tag: "v7"
service:
type: NodePort
port: 80
nodePort: 30300
options:
A: "AAA"
B: "BBB"
redis:
repicaCount: 1
image:
repository: "redis"
tag: "alpine"
service:
type: ClusterIP
port: 6379
At this time the code should look like this
# instavote chart directory
.
├── main
│ ├── Chart.yaml
│ └── values.dev.yaml
├── redis
│ ├── Chart.yaml
│ ├── charts
│ ├── templates
│ │ ├── NOTES.txt
│ │ ├── _helpers.tpl
│ │ ├── deployment.yaml
│ │ ├── hpa.yaml
│ │ ├── ingress.yaml
│ │ ├── service.yaml
│ │ ├── serviceaccount.yaml
│ │ └── tests
│ │ └── test-connection.yaml
│ └── values.yaml
└── vote
├── Chart.yaml
├── charts
├── templates
│ ├── NOTES.txt
│ ├── _helpers.tpl
│ ├── deployment.yaml
│ ├── hpa.yaml
│ ├── ingress.yaml
│ ├── service.yaml
│ ├── serviceaccount.yaml
│ └── tests
│ └── test-connection.yaml
├── values.staging.yaml
└── values.yaml
Install/Update depeendencies with
helm dependency update
ls
ls -l charts/
Clean up earlier helm installations if any
helm list -A
helm uninstall vote -n dev
helm uninstall vote -n staging
helm list -A
Now install the main chart with helm as
helm install instavote -n dev --values=values.dev.yaml . --dry-run
helm install instavote -n dev --values=values.dev.yaml .
validate with
helm list -A
kubectl get all -n dev
Exercises
- You will notice that the redis pods are being restarted every few seconds. Can you figure out why and fix it ? Apply the changes with helm.
- Now that you have deployed vote and redis, go ahead and add the code to deploy worker, db and result as well.
Cleaning up
To clean up all the resources, run the following command
helm uninstall instavote -n dev