Chart values and customization in Kubernetes - Step-by-Step Execution

Process Flow - Chart values and customization

Start with default Chart

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Create values.yaml

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Edit values.yaml to customize

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Run helm install/upgrade with values

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Helm merges values with Chart templates

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Kubernetes resources created with custom settings

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End

This flow shows how Helm uses a values.yaml file to customize a Chart before deploying Kubernetes resources.

Execution Sample

Kubernetes

helm install myapp ./mychart -f custom-values.yaml
kubectl get pods
helm upgrade myapp ./mychart -f custom-values.yaml

Install and upgrade a Helm Chart using a custom values file to change settings.

Process Table

Step	Command/Action	Values Used	Effect	Output/Result
1	helm install myapp ./mychart -f custom-values.yaml	custom-values.yaml overrides defaults	Chart templates rendered with custom values	Release 'myapp' installed, resources created
2	kubectl get pods	N/A	Check running pods	Shows pods with names from 'myapp' release
3	helm upgrade myapp ./mychart -f custom-values.yaml	custom-values.yaml overrides defaults	Chart templates re-rendered with updated values	Release 'myapp' upgraded, resources updated
4	kubectl get pods	N/A	Verify pods after upgrade	Pods reflect updated configuration
5	Exit	N/A	Process complete	Custom values applied successfully

💡 All steps complete; Helm applied custom values to Kubernetes resources

Status Tracker

Variable	Start	After Install	After Upgrade	Final
replicaCount	3 (default)	5 (custom-values.yaml)	5 (custom-values.yaml)	5
image.tag	"1.0.0" (default)	"2.1.0" (custom-values.yaml)	"2.1.0" (custom-values.yaml)	"2.1.0"
service.type	"ClusterIP" (default)	"LoadBalancer" (custom-values.yaml)	"LoadBalancer" (custom-values.yaml)	"LoadBalancer"

Key Moments - 3 Insights

Why does Helm use values.yaml instead of changing templates directly?

Helm keeps templates generic and uses values.yaml to customize deployments easily without editing templates. See execution_table step 1 where custom-values.yaml changes settings without touching templates.

What happens if a value is missing in custom-values.yaml?

Helm uses the default value from the Chart's values.yaml. This is why in variable_tracker some variables start with defaults and only change if overridden.

How does Helm apply changes on upgrade?

Helm re-renders templates with updated values and applies changes to Kubernetes resources, shown in execution_table step 3 and 4 where upgrade updates pods.

Visual Quiz - 3 Questions

Look at the variable_tracker after install. What is the replicaCount value?

A 1

B 3

C 5

D 0

💡 Hint

Check the 'After Install' column for replicaCount in variable_tracker

At which step in execution_table does Helm upgrade the release?

A Step 1

B Step 3

C Step 2

D Step 4

💡 Hint

Look for the 'helm upgrade' command in execution_table

If custom-values.yaml did not specify image.tag, what would happen?

A The default image.tag from Chart is used

B Helm would fail to deploy

C Pods would not start

D Helm ignores image.tag completely

💡 Hint

Refer to key_moments about missing values and variable_tracker start values

Concept Snapshot

Helm Charts use values.yaml files to customize deployments.
Custom values override defaults without changing templates.
Use 'helm install -f values.yaml' to apply custom settings.
Upgrades reapply templates with updated values.
Missing values fall back to Chart defaults.
This keeps deployments flexible and reusable.

Full Transcript

This visual execution shows how Helm uses a values.yaml file to customize Kubernetes deployments. First, a Helm Chart has default values. We create a custom-values.yaml file to override some settings like replica count and image tag. When we run 'helm install' with the custom values file, Helm merges these values with the Chart templates and deploys resources accordingly. We verify pods are running with 'kubectl get pods'. Later, we run 'helm upgrade' with the same custom values to update the deployment. Helm re-renders templates with the updated values and applies changes to the cluster. Variables like replicaCount and image.tag change from defaults to custom values, as tracked in the variable tracker. Key moments clarify why values.yaml is used, what happens if values are missing, and how upgrades apply changes. The quiz tests understanding of these steps and variable changes. This process helps keep Helm Charts reusable and easy to customize for different environments.