How to Properly Set ConfigMap from values.yaml in Helm Charts

Описание: Discover the right way to create a ConfigMap in Kubernetes using Helm Charts, ensuring your YAML structure is correct and avoiding common pitfalls.
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This video is based on the question https://stackoverflow.com/q/76271037/ asked by the user 'java_maestros' ( https://stackoverflow.com/u/4782160/ ) and on the answer https://stackoverflow.com/a/76272754/ provided by the user 'Andromeda' ( https://stackoverflow.com/u/10059628/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Setting Up ConfigMap from values.yaml in Helm Charts: A Step-by-Step Guide

When working with Helm charts in Kubernetes, you often need to manage configuration files through ConfigMaps. In this guide, we'll tackle a common question: How can you set a ConfigMap from values.yaml?

Understanding the Problem

Imagine you have a Spring configuration file named application.yaml containing crucial settings for your application. You want to reuse this file in your Kubernetes ConfigMap, and you've defined the properties in Helm's values.yaml. However, when you try to deploy, you encounter an error:

[[See Video to Reveal this Text or Code Snippet]]

This error indicates that there's something wrong with the way the YAML is structured in your deployment. Let’s solve this issue step-by-step.

Original Configuration Overview

Here's a breakdown of the files you're currently using:

1. application.yaml

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2. values.yaml

Here’s how you tried to structure it within values.yaml for your ConfigMap:

[[See Video to Reveal this Text or Code Snippet]]

3. configmap.yaml

You originally structured your ConfigMap file like this:

[[See Video to Reveal this Text or Code Snippet]]

Identifying the Issues

The problem arises from how you are trying to render and format the YAML for the ConfigMap. The error indicates that the structure does not meet the expected format, leading to the failure during unmarshalling.

The Correct Approach

To fix the error and enhance your configuration, you can simplify your approach considerably. Here’s the revised method:

Improved configmap.yaml

[[See Video to Reveal this Text or Code Snippet]]

Explanation of Changes

Using toYaml: This function transforms the Go template data structure directly into YAML format. It takes care of formatting for you, ensuring the output is correctly structured.

Indentation: The nindent 2 function adjusts the indentation to ensure that content is formatted properly within the ConfigMap data field.

Conclusion

By adopting this streamlined approach, you eliminate the risk of YAML formatting errors and simplify your configuration management. The updated ConfigMap setup is more readable and less prone to mistakes.

If you ever encounter similar issues, remember to check the YAML structure carefully and consider using Helm template functions like toYaml for cleaner code. Thank you for joining us on this journey towards efficient Kubernetes configuration management!