KubernetesHow-ToBeginner · 3 min read

How to Use Helm Upgrade for Kubernetes Deployments

Use helm upgrade to update an existing Helm release with new chart versions or configuration changes. The command applies changes without uninstalling the release, keeping your app running smoothly.

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Syntax

The helm upgrade command updates a release with a new chart or configuration. It requires the release name and the chart path or name. Optional flags control behavior like installing if missing or setting values.

RELEASE: Name of the Helm release to upgrade.
CHART: Path or name of the chart to use for upgrade.
--install: Installs the release if it does not exist.
--values or -f: Specify YAML files with configuration values.
--set: Override values directly in the command line.

bash

helm upgrade [RELEASE] [CHART] [flags]

# Example flags:
# --install  # install if release missing
# -f values.yaml  # use values file
# --set key=value  # override values

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Example

This example upgrades a release named myapp using a local chart directory ./mychart. It sets a new image tag using --set and applies a values file.

bash

helm upgrade myapp ./mychart --install -f custom-values.yaml --set image.tag=v2.0.1

Output

Release "myapp" has been upgraded. Happy Helming! NAME: myapp LAST DEPLOYED: Fri Apr 26 15:00:00 2024 NAMESPACE: default STATUS: deployed REVISION: 2 TEST SUITE: None

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Common Pitfalls

Common mistakes when using helm upgrade include:

Not using --install when the release does not exist, causing upgrade to fail.
Forgetting to update the chart version or path, so no changes apply.
Incorrect YAML syntax in values files causing upgrade errors.
Overriding values incorrectly with --set, leading to unexpected configurations.

Always check the release status after upgrade with helm status [RELEASE].

bash

## Wrong: upgrade fails if release missing
helm upgrade myapp ./mychart

## Right: install if missing
helm upgrade myapp ./mychart --install

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Quick Reference

Flag	Description
--install	Install release if it does not exist
-f, --values	Specify values YAML file
--set	Set or override values on the command line
--namespace	Specify Kubernetes namespace
--timeout	Time to wait for upgrade to complete

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Key Takeaways

Use helm upgrade to update releases without downtime.

Add --install to create the release if missing.

Use -f or --set to customize configuration during upgrade.

Check upgrade success with helm status [RELEASE].

Avoid YAML syntax errors in values files to prevent upgrade failures.