Helm is a new templating tool for your applications. As with any other tool, it has thicks and hacks that you probably heard, but haven’t actually tried. In this lesson, we will review some of those approaches and also pass through different ways of deploying project workloads to the Kubernetes cluster.

1. Design templates and inheritance.
Best practices for K8S releases.
2022 | apprecode.com
CEO and Co-founder
BY VOLODYMYR SHYNKAR
WRITE YOUR HELM CHARTS
AS A PROFESSIONAL

2. [devops@stage ~]$ cat ABOUT_ME.md
7+ years of commercial DevOps experience.
Overall 9+ years of Engineering
Successfully migrated, rolled out, consulted over
20 projects in the healthcare, gambling,
automotive, fintech, ecommerce, construction
industries
Certified SAFe Agile Software Engineer
Addicted to IoT and Smart Home
Cyclist, promoter of a healthy lifestyle
[devops@stage ~]$
VOLODYMYR SHYNKAR
CEO/Co-founder at AppRecode

3. AGENDA
Helm - benefits and lifecycle
Helm - basic functions and templates
Helm - advanced loops and inheritance
CI/CD releases and integrations
01
02
03
04

4. HELM - BENEFITS
AND LIFECYCLE
01

5. BENEFITS Packaging way (Artifact)
Well customizable application
during deployment
Gets your CI/CD pipelines to the
next level
Ready to use community
packages as dependencies
Reduces the complexity of
creating various environments

6. BENEFITS
Can be reused
Versionable
Easy rollbacks
Better than your ex kubectl apply -f

7. How to use? It is easy!

8. Chart structure
~ $ helm create myapp
Creating myapp

9. Chart.yaml

10. Dependencies

11. What is Helm Repository?
https://charts.bitnami.com/bitnami/index.yaml
GitHub Pages
GitHub branch
S3 WSH (CloudFront)
S3 Proxy to serve repo internally
Any other web server

12. Dependencies

13. Values file
Must have
Built-in
Inteprolated? Yes, but no.

14. Multiple envs
Multiple values files
Override via console argument
Git branches (not the best)

15. How to verify and test charts?
Lint: helm lint
Print results: helm template –debug
Print results and verify with cluster:
helm install --dry-run –debug
Validate templates: helm validate
Connection tests via hooks in templates/tests:
helm.sh/hook: test

16. Versioning and Release
Continuous development/improvement
Keep track of the changes + change log
Different environments
Your are provide Helm charts as a service

17. Helm - basic functions
and templates
02

18. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates

19. Trigger deployment if ConfigMap was changed
Built-in Objects
Values file
Custom variables
Global values
Named templates
Release, Chart, Files, Capabilities, Template

20. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates

21. Interpolation in Values file
Built-in Objects
Values file
Custom variables
Global values
Named templates

22. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates
Sometimes you might need to use the same construction several times.
In this case you can create a custom variable {{- $fullName := include ”myapp.fullname" . -}}

23. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates
• Sometimes you might need to use the same inputs in several charts
• You don’t want to manage the same scope in several places
• You can mismatch or forget to update another place

24. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates
This template will help you to set repeated attributes which should be common for your manifects
- labels, selectors, names, complicated constructions what is that?

25. Variables
Built-in Objects
Values file
Custom variables
Global values
Named templates

26. Functions and Pipelines
Helm has over 60 available functions.
quote; squote; default; lower; upper; repeat; replace; printf;
lookup; range; with; if; indent; nindent; toYaml; camelcase

27. Helm - advanced loops
and inheritance
03

28. Loops and conditions
Finally, we came to the most exciting part.
•if/else for creating conditional blocks
•with to specify a scope
•range, which provides a "for each"-style loop

29. Conditions
If not | eq | or | and
{{- if and .Values.val1 (not .Values.val2) }}

30. Loops
Modifying scope using with
Looping with the range action
Another use case of using Custom Variable
We can reffer a root scope by $ sign.

31. Loops
Modifying scope using with
Looping with the range action
Another use case of using Custom Variable
We can reffer a root scope by $ sign.

32. Inheritance
Helm has several inheritances
• charts
• global values
• templates

33. Sharing Templates with Subcharts
Parent charts and subcharts can share templates. Any defined block in any
chart is available to other charts.
For example, we can define a simple template like this:
{{- define "labels" }}from: mysubchart{{ end }}

34. CD releases and
integrations
04

35. CI/CD releases for Helm charts
Release your Helm charts as any other products
https://github.com/marketplace/actions/helm-chart-releaser

36. CD releases with Helm
You can keep your Helm charts in code repo and just replace
image tag during release
You can reuse the Chart as dependency and override things
with short values file(s)

37. CD releases with Helm and GitOps
All the same as on previous slide, but GitOps operator will
take care of:
• Managing versions
• Keep state and avoid diffs
• Overview of installed resources and their statuses
• Nice UI with possibility to install other Helm charts without
touching Kubernetes at all

38. Helm and OperatorHub
OperatorHub.io is a new home for the Kubernetes community
to share Operators. Find an existing Operator or list your own
today.

39. WE ARE CODE
DEPLOY
BUILD
ARCHITECTURE
HIRING
WE ARE ARCHITECTURE
WE ARE DESIGN
DESIGN
WE ARE BUILD
WE ARE DEPLOY
WE ARE HIRING
CODE