Creating custom Helm charts in Kubernetes - Visual Walkthrough

Process Flow - Creating custom Helm charts

Start: Define Chart Structure

↓

Create Chart.yaml

↓

Create values.yaml

↓

Create templates/ directory

↓

Add Kubernetes YAML templates

↓

Use placeholders for values

↓

Package and install chart

↓

Chart deployed with custom values

↓

END

This flow shows the step-by-step process of creating a Helm chart: starting with structure, adding metadata, templates, and values, then packaging and deploying.

Execution Sample

Kubernetes

helm create mychart
# Edit mychart/Chart.yaml
# Edit mychart/values.yaml
# Add templates/deployment.yaml with placeholders
helm install myrelease mychart -f custom-values.yaml

This sequence creates a Helm chart, customizes it, and installs it with custom values.

Process Table

Step	Action	File/Command	Effect/Result
1	Create new chart skeleton	helm create mychart	Folder 'mychart' with default files created
2	Edit Chart.yaml	mychart/Chart.yaml	Set chart name, version, description
3	Edit values.yaml	mychart/values.yaml	Define default configuration values
4	Add template with placeholders	mychart/templates/deployment.yaml	Template uses {{ .Values.key }} for dynamic values
5	Package chart (optional)	helm package mychart	Chart packaged as .tgz file
6	Install chart with custom values	helm install myrelease mychart -f custom-values.yaml	Kubernetes resources deployed with custom settings
7	Verify deployment	kubectl get pods	Pods running as per chart configuration
8	Exit	-	Chart deployed successfully, process complete

💡 Chart installed and Kubernetes resources created, no further steps

Status Tracker

Variable/File	Start	After Step 2	After Step 3	After Step 4	After Step 6	Final
Chart.yaml	empty template	name, version set	unchanged	unchanged	unchanged	unchanged
values.yaml	default values	unchanged	custom values added	unchanged	used for deployment	unchanged
templates/deployment.yaml	default template	unchanged	unchanged	placeholders added	rendered with values	unchanged
Kubernetes deployment	none	none	none	none	created with custom values	running pods

Key Moments - 3 Insights

Why do we use placeholders like {{ .Values.key }} in templates?

Placeholders allow templates to use dynamic values from values.yaml or custom files, as shown in step 4 and step 6 of the execution_table.

What happens if we don't provide a custom values file during install?

Helm uses default values from values.yaml, so deployment uses those defaults (see step 6 and variable_tracker for values.yaml).

Why do we need to edit Chart.yaml if it has defaults?

Chart.yaml defines metadata like name and version, important for identifying the chart, as shown in step 2.

Visual Quiz - 3 Questions

Look at the execution_table, at which step are placeholders added to templates?

A Step 2

B Step 4

C Step 6

D Step 1

💡 Hint

Check the 'Action' column for 'Add template with placeholders' in execution_table

According to variable_tracker, what is the state of values.yaml after Step 3?

A Custom values added

B Default values only

C Empty file

D Used for deployment

💡 Hint

Look at values.yaml row under 'After Step 3' in variable_tracker

If you skip editing Chart.yaml, what is the likely effect?

A Chart will fail to install

B Templates won't render

C Chart installs with default metadata

D Values.yaml is ignored

💡 Hint

Refer to step 2 and the key_moments about Chart.yaml importance

Concept Snapshot

Creating custom Helm charts:
1. Use 'helm create <name>' to scaffold.
2. Edit Chart.yaml for metadata.
3. Define default config in values.yaml.
4. Add templates with {{ .Values.key }} placeholders.
5. Install with 'helm install' and optional custom values.
6. Kubernetes resources deploy using these configs.

Full Transcript

Creating custom Helm charts involves starting with a scaffold using 'helm create'. Then, you edit Chart.yaml to set the chart's name and version. Next, you define default configuration values in values.yaml. Templates in the templates directory use placeholders like {{ .Values.key }} to insert these values dynamically. You can package the chart or install it directly with 'helm install', optionally providing a custom values file to override defaults. This process results in Kubernetes resources deployed with your custom settings.