Charts
In the previous chapters when dealing with Kubernetes, we learned how to create and manage a bunch of different Kubernetes components and applications by using yaml files. As you can imagine handling multiple yaml files for every single application can get quite cumbersome once you have more than just two or three deployments in parallel. It’s a lot of steps you have to take to get everything up and running, and handling versioning between the different moving parts can be difficult at times.
To make it short: Similar to Docker where we packaged all our dependencies into one Dockerfile, it would be convenient to be able to package all the different components of a kubernetes application (deployment.yaml, service.yaml, …) into one configuration and deploy that configuration as a single step. This is where helm steps in.
Exercise - The components of a helm chart
An empty helm chart has already been created for the postgresdb. You can go ahead and list it’s contents with the tree command.
tree postgresdb/helmchart/
This should display output similar to this:
helmchart
├── charts
├── Chart.yaml
├── templates
└── values.yaml
2 directories, 2 filesAs you can see, a minimal helm chart consist of four parts:
- The Chart.yaml contains metadata like the name of the chart or the version of the application.
- The values.yaml file is used to store parameters which can later be injected into the template files.
- The templates directory contains all of your kubernetes .yaml files like deployment and service definitions.
- The charts directory contains all of the dependencies of your chart.
Info
Don’t worry about the empty templates/ and charts/ directories for now, we are going to put files in there soon!
Exercise - Taking a look at the Chart.yaml file
Let’s start by looking at the Chart.yaml file that is already there.
cat postgresdb/helmchart/Chart.yaml
apiVersion: v1
appVersion: "1.0"
name: postgresdb
description: postgresdb
version: 0.1.0As you can see there is not much going on in this file. We declare the version of the chart and the application and we give the chart a name and a description.
Exercise - Add templates to our chart
To make the chart do anything we have to provide it with templates. When we finally deploy the chart, helm will look into the templates/ directory and deploy every kubernetes resource definition it finds.
cp postgres.yaml postgresdb/helmchart/templates/
cp postgres-service.yaml postgresdb/helmchart/templates/
Warning
You may still have an instance of a postgres deployment running from previous exercises. To avoid name conflicts please
change all postgresdb values of name and app in postgresdb/helmchart/templates/postgres.yaml and
postgresdb/helmchart/templates/postgres-service.yaml to helm-postgresdb.
Your postgresdb/helmchart/ directory should look like this now:
postgresdb/helmchart/
├── charts
├── Chart.yaml
├── templates
│ └── postgres-service.yaml
│ └── postgres.yaml
└── values.yaml
2 directories, 4 filesAnd that’s it, in the next step we can look at deploying the newly created chart!
Exercise - Deploying our first helm chart
In the previous step we created a minimal helm chart with two templates, the postgresdb deployment and the postgresdb service. To install this chart on a kubernetes cluster all we have to do is run the helm install command:
helm install postgres ./postgresdb/helmchart/
Exercise - Listing helm releases
What we have just created is called a release. A release is just one of many possible deployed instances of a helm
chart. We can list all releases by running helm list which in our case should produce output like this:
NAME NAMESPACE REVISION UPDATED STATUS CHART APP VERSION
postgres <your_namespace> 1 2026-01-29 14:16:37.517790785 +0100 CET deployed postgresdb-0.1.0 1.0Exercise - Verifying the release
To verify that the release was installed successfully we can run kubectl get svc,deploy,po and watch helm deploy our
database. It should list the following resources:
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/helm-postgresdb ClusterIP 10.0.255.204 <none> 5432/TCP 56s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/helm-postgresdb 1/1 1 1 56s
NAME READY STATUS RESTARTS AGE
pod/helm-postgresdb-74dd68db99-gr7xg 1/1 Running 0 56sAlternatively you can use helm status <release name> to show the status of a given release.
Running helm status postgres should render output similar to this:
NAME: postgres
LAST DEPLOYED: Thu Jan 29 14:16:37 2026
NAMESPACE: <your_namespace>
STATUS: deployed
REVISION: 1
TEST SUITE: NoneExercise - Postgres cleanup
Similar to helm install we can run helm uninstall <release name> to uninstall a release. Please go ahead and
uninstall our postgresdb release!
Exercise - Helm repositories
We already learned about the concept of repositories in the Docker section where we used repositories to store our images and make them accessible for the public. Helm uses the same concept to manage charts and allows us to use
helm install
to install a chart from a public repository.
For reference, the CNCF is building a web-based application that enables finding, installing, and publishing packages and configurations for CNCF projects, also including Helm charts. It is called Artifact Hub .
To install a helm chart from a remote source we have to take a few steps:
- Add the helm repository with
helm repo add <repository url> - Fetch updates from the remote repositories with
helm repo update - Install the chart with
helm install <repository/chart>
Please run the following commands to install a simple WordPress deployment from its public repository:
-
helm repo add bitnami https://charts.bitnami.com/bitnami -
helm repo update -
helm search repo wordpress -
helm search repo --versions bitnami/wordpress -
helm install wordpress bitnami/wordpress --version 28.1.2
Why this specific version? Well, this version was last tested by us, and we don’t want to just blindly install latest,
do we?
Again, you can verify the proper creation of the deployment by running kubectl get svc,deploy,po, which among other
things should list the following:
Exercise - Wordpress cleanup
Congratulations, you just deployed a helm chart from a public chart repository! In the next chapter we are going to look at configuring charts via command line parameters and custom values files. For now you can go ahead and uninstall the wordpress release again.
helm uninstall wordpress
Watch via kubectl get svc,deploy,po how the resources will get deleted. Does anything remain?