A dynamic approach to Kubernetes add-on and application management
Tags: kubernetes, devops, showdev, cloud
Published: 2023-10-10 12:09:39

As the demand for scalable and efficient Kubernetes infrastructure continues to grow, so does the need for automated solutions to manage clusters. [ClusterAPI](https://github.com/kubernetes-sigs/cluster-api) has emerged as a powerful solution for programmatically creating, upgrading, and deleting clusters on demand.

One of the key challenges in managing Kubernetes clusters is the installation and upgrading of cluster add-ons and applications. This can be a time-consuming and complex process, especially for organizations that manage a large number of clusters. Existing solutions for automating cluster add-ons often require a significant degree of user interaction.

## Add-on and application management

[Projectsveltos](https://github.com/projectsveltos) is a set of Kubernetes controllers that takes a more intelligent approach to cluster add-on management.

It is able to automatically identify clusters, comprehend their current state, and install and upgrade add-ons with minimal user interaction. It offers support for Helm charts, raw YAMLs, and Kustomize or any combination of those.


![Sveltos: Kubernetes add-on deployment](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/w99vuylbo5ednunosv9z.gif)

![Orderly deploying Kubernetes add-ons with Projectsveltos](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/0j9ggadljv7p8cyhzhlk.gif)

## Templates

Add-ons and applications can be expressed as templates. At deployment time, Projectsveltos will instantiate the templates, using information gathered by fetching resources from the management cluster or the managed clusters. This allows to customize the deployment of add-ons and applications based on the specific needs of each cluster. For example, deploy an add-on with different configuration options depending on the cluster.


![Expressing add-ons as templates](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/g75r61m9de880kv4iwzw.png)

Projectsveltos templates can also be used to coordinate with other open source projects. For example, Projectsveltos can coordinate with Crossplane to create a Google Cloud Storage bucket for each managed cluster and then deploy an application in each managed cluster that uploads a file to the proper bucket.

![Sveltos, ClusterAPI and Crossplane](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/pm8puxucfzchpf8vdvt9.gif)

Or with External Secret Operator:

![Sveltos and External Secret Operator](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/to5ouwuikpceqqk2s7uy.gif)

## Resource Deployment Order

Sveltos allows to specify the order in which Kubernetes resources are deployed.

![Add-on deployment order](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/3rkz89zw8lk5k7ggwgpj.gif)

## Deploy add-ons based on cluster runtime state

[Projectsveltos](https://github.com/projectsveltos) can be instructed to classify clusters based on their run-time state and update deployed add-ons and application as run-time state changes.

In this example, when a cluster is upgraded, Projectsveltos automatically upgrades add-ons and applications deployed in such cluster.

![Cluster classification based on run-time state](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/fg17mnex3rodn20t31kb.gif)

## Conclusion

[Projectsveltos](https://github.com/projectsveltos) is a powerful and flexible tool for managing Kubernetes cluster add-ons and applications:

1. **Reduced time and effort**: Projectsveltos automates the installation and upgrading of cluster add-ons, freeing up IT staff to focus on other tasks.

2. **Improved consistency**: Projectsveltos ensures that add-ons are installed and upgraded consistently across all clusters.

3. **Reduced risk**: Projectsveltos reduces the risk of errors during the installation and upgrading process.

4. **Increased agility**: Projectsveltos makes it easier to deploy and manage new add-ons, and to keep existing add-ons up to date.

If you enjoyed this article, please check out the [Sveltos GitHub repo](https://github.com/projectsveltos).

The GitHub repo is a great resource for getting started with Sveltos. It contains the code, documentation, and examples. You can also find the latest news and updates on the project on the GitHub repo.

If you have any feedback, bugs, or PRs, please feel free to contribute to the project. Your contributions will help make Sveltos even better.