Creating and Managing Releases
When you install a Helm chart, a release is created. Each release is like an application package—a collection of related Kubernetes objects. Since Helm tracks all objects associated with a release, it allows you to upgrade, downgrade, or uninstall a release without affecting other deployments. For instance, even if you deploy the same chart twice, each release remains independent:Installing an Older Version
To see Helm in action, let’s create a new release by installing an older version of the NGINX chart. Use the version flag during installation:If you discover security vulnerabilities or need feature updates, Helm makes it easy to upgrade your application along with all associated Kubernetes configurations.
Upgrading Releases
Helm’s upgrade functionality allows seamless transition to new versions. When you upgrade a release, Helm replaces the old Pod with a new one that includes updated settings and images. Here’s an example of upgrading the existing NGINX release:Rollbacks
If an upgrade leads to unexpected behavior, Helm supports rollbacks. Rolling back reverts the release to its previous known-good state. For example, to rollback the NGINX release to revision 1, run:Remember that while rollbacks restore Kubernetes manifest configurations, they do not include the actual data stored in persistent volumes or external databases. Always ensure you have a separate backup solution for persistent data.
Upgrading Complex Charts
When working with more complex applications, such as WordPress, additional parameters might be required during an upgrade. Missing these parameters can result in errors like the one below:Summary
Helm simplifies lifecycle management by:
By following the practices outlined in this article, you can streamline application management across your Kubernetes clusters. Practice these Helm commands with hands-on exercises to deepen your understanding and improve your deployment workflows.
For more information, consider exploring the Helm Documentation.