Helm charts concept in Kubernetes - Step-by-Step Execution

Process Flow - Helm charts concept

Start: Need to deploy app

↓

Create Helm Chart

↓

Define Templates + Values

↓

Run helm install

↓

Helm renders templates

↓

Kubernetes resources created

↓

App deployed and managed

↓

Use helm upgrade/rollback for changes

Helm charts package app configs and templates. Helm renders these to create Kubernetes resources, then deploys and manages the app.

Execution Sample

Kubernetes

helm create myapp
helm install myapp ./myapp
helm upgrade myapp ./myapp
helm rollback myapp 1

Create a Helm chart, install it to deploy app, upgrade to change app, rollback to revert.

Process Table

Step	Action	Input/Command	Result	Notes
1	Create Helm chart	helm create myapp	Folder 'myapp' with chart files created	Chart scaffold ready for customization
2	Install chart	helm install myapp ./myapp	Kubernetes resources created	App deployed using rendered templates
3	Upgrade chart	helm upgrade myapp ./myapp	Resources updated	Changes applied to app without downtime
4	Rollback chart	helm rollback myapp 1	Resources reverted to previous state	Undo upgrade to stable version
5	Exit	No further commands	App running with managed lifecycle	Helm manages app versions and state

💡 App deployed and managed by Helm; lifecycle commands complete

Status Tracker

Variable	Start	After Step 1	After Step 2	After Step 3	After Step 4	Final
Chart files	None	Created scaffold files	Unchanged	Unchanged	Unchanged	Unchanged
Kubernetes resources	None	None	Created from templates	Updated with new config	Reverted to old config	Running stable state
App version	None	None	v1 (initial)	v2 (upgraded)	v1 (rolled back)	v1 (stable)

Key Moments - 3 Insights

Why do we need to run 'helm create' before installing?

Step 1 in the execution_table shows 'helm create' makes the chart files needed to define app templates and configs. Without this, 'helm install' has nothing to deploy.

What happens when we run 'helm upgrade'?

Step 3 shows 'helm upgrade' updates Kubernetes resources with new configs from the chart, changing the app without downtime.

How does 'helm rollback' affect the app?

Step 4 shows 'helm rollback' reverts resources to a previous version, undoing upgrades to restore a stable app state.

Visual Quiz - 3 Questions

Look at the execution_table, what is created after running 'helm create myapp'?

A Kubernetes resources

B App running in cluster

C Chart scaffold files

D Rollback version

💡 Hint

See Step 1 in execution_table under Result column

At which step does the app version change to v2?

A Step 2

B Step 3

C Step 4

D Step 1

💡 Hint

Check variable_tracker row 'App version' after each step

If you skip 'helm upgrade' and run 'helm rollback', what happens?

A Rollback fails because no upgrade happened

B App version stays at v1

C Resources update to v2

D Chart files get deleted

💡 Hint

Rollback reverts to previous version; without upgrade, no newer version exists (see key_moments explanation)

Concept Snapshot

Helm charts package Kubernetes app configs and templates.
Use 'helm create' to scaffold a chart.
'helm install' deploys app by rendering templates.
'helm upgrade' updates app without downtime.
'helm rollback' reverts to previous app version.
Helm manages app lifecycle easily.

Full Transcript

Helm charts help package and deploy Kubernetes apps by combining templates and configuration values. First, you create a chart scaffold with 'helm create'. Then, 'helm install' renders templates into Kubernetes resources and deploys the app. When you want to change the app, 'helm upgrade' updates resources smoothly. If something goes wrong, 'helm rollback' restores the previous stable version. This process lets you manage app versions and lifecycle simply and reliably.

Practice

1. What is the primary purpose of a Helm chart in Kubernetes?

easy

A. To replace kubectl commands

B. To monitor Kubernetes cluster health

C. To package and deploy Kubernetes applications easily

D. To create Docker images

Solution

1. Step 1: Understand Helm chart role

   A Helm chart bundles Kubernetes app resources for easy deployment and sharing.

2. Step 2: Compare options

   Options B, C, and D describe other tools or tasks unrelated to Helm charts.

3. Final Answer:

   To package and deploy Kubernetes applications easily -> Option C

4. Quick Check:

   Helm chart = package & deploy app [OK]

Hint: Helm charts bundle apps for easy deployment [OK]

Common Mistakes:

• Confusing Helm with monitoring tools
• Thinking Helm replaces kubectl entirely
• Assuming Helm builds Docker images

2. Which Helm command is used to create a new chart skeleton?

easy

A. helm rollback

B. helm install

C. helm upgrade

D. helm create

Solution

1. Step 1: Identify command purpose

   helm create generates a new chart directory with default files.

2. Step 2: Eliminate other commands

   helm install deploys charts, helm upgrade updates releases, helm rollback reverts upgrades.

3. Final Answer:

   helm create -> Option D

4. Quick Check:

   New chart skeleton = helm create [OK]

Hint: Use helm create to start a chart [OK]

Common Mistakes:

• Using helm install to create charts
• Confusing upgrade with create
• Trying rollback to create charts

3. Given the command helm install myapp ./mychart, what happens?

medium

A. Installs the release 'myapp' using the chart from the local directory './mychart'

B. Creates a new chart named 'myapp' in './mychart'

C. Upgrades the release 'myapp' with './mychart'

D. Rolls back the release 'myapp' to './mychart'

Solution

1. Step 1: Understand helm install syntax

   helm install [release-name] [chart-path] deploys the chart as a release.

2. Step 2: Analyze given command

   Here, 'myapp' is the release name, './mychart' is the chart directory to deploy.

3. Final Answer:

   Installs the release 'myapp' using the chart from the local directory './mychart' -> Option A

4. Quick Check:

   helm install = deploy chart [OK]

Hint: helm install deploys chart as release [OK]

Common Mistakes:

• Thinking install creates charts
• Confusing install with upgrade or rollback
• Misunderstanding release name vs chart path

4. You run helm upgrade myapp ./mychart but get an error: "release: not found". What is the likely cause?

medium

A. The release 'myapp' does not exist yet

B. The chart path './mychart' is invalid

C. You need to use helm install instead of upgrade

D. The Kubernetes cluster is down

Solution

1. Step 1: Understand helm upgrade error

   The error "release: not found" means the named release does not exist in the cluster.

2. Step 2: Identify correct cause

   Since upgrade updates existing releases, trying to upgrade a non-existent release causes this error.

3. Final Answer:

   The release 'myapp' does not exist yet -> Option A

4. Quick Check:

   Upgrade needs existing release [OK]

Hint: Upgrade fails if release not installed yet [OK]

Common Mistakes:

• Assuming chart path error causes this message
• Using upgrade instead of install for new release
• Blaming cluster status without checking release

5. You want to deploy a Helm chart and be able to easily revert to the previous version if needed. Which Helm commands should you use in order?

hard

A. helm create, helm install, helm rollback

B. helm install, helm upgrade, helm rollback

C. helm create, helm upgrade, helm rollback

D. helm install, helm create, helm rollback

Solution

1. Step 1: Understand deployment and version control

   First, use helm install to deploy the initial release.

2. Step 2: Manage updates and rollback

   Use helm upgrade to update the release, and helm rollback to revert if needed.

3. Step 3: Eliminate incorrect sequences

   helm create is for making charts, not deployment steps. It should not be in the deploy/rollback sequence.

4. Final Answer:

   helm install, helm upgrade, helm rollback -> Option B

5. Quick Check:

   Install -> Upgrade -> Rollback = C [OK]

Hint: Install first, then upgrade, rollback if needed [OK]

Common Mistakes:

• Using helm create in deployment sequence
• Skipping install before upgrade
• Confusing rollback with create