Skip to content

Distribute Add-ons

What is Sveltos?

Sveltos is a set of Kubernetes controllers that run in the management cluster. From the management cluster, Sveltos can manage add-ons and applications on a fleet of managed Kubernetes clusters.

Sveltos comes with support to automatically discover Cluster API (CAPI) powered clusters, but it doesn't stop there. We can easily register any other cluster (on-prem, Cloud) and manage Kubernetes add-ons seamlessly.

Sveltos managing clusters

How does it work?

ClusterProfile and Profile are the Custom Resource Definitions (CRDs) used to instruct Sveltos which add-ons to deploy on a set of clusters.

  • ClusterProfile: It is a cluster-wide resource. It can match any cluster and reference any resource regardless of their namespace.

  • Profile: It is a namespace-scoped resource that is specific to a single namespace. It can only match clusters and reference resources within its own namespace.

By creating a ClusterProfile and Profile instances, we can easily deploy the following points across a set of Kubernetes clusters.

  • Helm charts
  • Resources assembled with Kustomize
  • Raw Kubernetes YAML/JSON manifests

Define which Kubernetes add-ons to deploy and where:

  1. Select one or more clusters using a Kubernetes label selector;
  2. List the Kubernetes add-ons that need to be deployed on the selected clusters

Simple as that!

CRDs Details

To get a list of all the available options defined in a ClusterProfile and Profile resources, take a look at the ClusterProfile and the Profile deep dive documentation.

Example: Deploy Kyverno using a ClusterProfile

The example deploys a Kyverno Helm chart in every cluster with the label selector set to env=prod.

Step 1: Register Clusters with Sveltos (non-CAPI clusters)

The first step is to register clusters with Sveltos to receive the required addons and deployments. If the clusters are not registered yet, follow the instructions outlined here.

$ kubectl get sveltosclusters -n projectsveltos --show-labels

NAME        READY   VERSION          LABELS
cluster12   true    v1.26.9+rke2r1   sveltos-agent=present
cluster13   true    v1.26.9+rke2r1   sveltos-agent=present

Note

The CAPI clusters are detected automatically by Sveltos. They are registered in the projectsveltos namespace by default. If we register the clusters in a different namespace, update the command above.

Step 2: Assign Labels

Once the clusters are registered and in a "READY" state, we can assign labels and start deploying add-ons and applications. For that, we can use the kubectl label command.

$ kubectl label sveltosclusters cluster12 -n projectsveltos env=prod
$ kubectl label sveltosclusters cluster13 -n projectsveltos env=prod

Step 3: Create the ClusterProfile

The third step is to create a ClusterProfile and apply it to the management cluster.

Sveltos ClusterProfile Kyverno

cat > clusterprofile_kyverno.yaml <<EOF
apiVersion: config.projectsveltos.io/v1beta1
kind: ClusterProfile
metadata:
name: kyverno
spec:
clusterSelector:
    matchLabels:
    env: prod
syncMode: Continuous
helmCharts:
- repositoryURL:    https://kyverno.github.io/kyverno/
    repositoryName:   kyverno
    chartName:        kyverno/kyverno
    chartVersion:     v3.3.3
    releaseName:      kyverno-latest
    releaseNamespace: kyverno
    helmChartAction:  Install
EOF

$ export KUBECONFIG=/path/to/kubeconfig/management/cluster

$ kubectl apply -f "clusterprofile_kyverno.yaml"

$ sveltosctl show addons

+--------------------------+---------------+-----------+----------------+---------+-------------------------------+------------------+
|         CLUSTER          | RESOURCE TYPE | NAMESPACE |      NAME      | VERSION |             TIME              | CLUSTER PROFILES |
+--------------------------+---------------+-----------+----------------+---------+-------------------------------+------------------+
| projectsveltos/cluster12 | helm chart    | kyverno   | kyverno-latest | 3.2.5   | 2023-12-16 00:14:17 -0800 PST | kyverno          |
| projectsveltos/cluster13 | helm chart    | kyverno   | kyverno-latest | 3.2.5   | 2023-12-16 00:14:17 -0800 PST | kyverno          |
+--------------------------+---------------+-----------+----------------+---------+-------------------------------+------------------+

Sveltos in action

Sveltos in action

Note

To explore and install the sveltosctl utility, take a look at the installation guide found here.

More Resources

The easiest way to try out Sveltos is by following the Quick Start guide. If you prefer a video demonstration, watch the Sveltos introduction video on YouTube.