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Inventory and Transport Spaces#

What is an ITS?#

An ITS is a space (a Kubernetes-like API server with storage) that:

  • Holds inventory information about all registered WECs using ManagedCluster.v1.cluster.open-cluster-management.io objects
  • Contains a "customization-properties" namespace with ConfigMaps carrying additional properties for each WEC
  • Manages mailbox namespaces that correspond 1:1 with each WEC, holding ManifestWork objects
  • Runs the OCM (Open Cluster Management) Cluster Manager to synchronize objects with the WECs

Creating an ITS#

An ITS can be created in several ways:

Using the KubeStellar Core Helm Chart#

The recommended approach is to use the KubeStellar Core Chart:

helm upgrade --install ks-core oci://ghcr.io/kubestellar/kubestellar/core-chart \
  --set-json='ITSes=[{"name":"its1", "type":"vcluster"}]'

You can customize your ITS by specifying: - name: A unique name for the ITS - type: - vcluster (default): Creates a virtual cluster - host: Uses the KubeFlex hosting cluster itself - external: Uses an external cluster - install_clusteradm: true (default) or false to control OCM installation

Using the KubeFlex CLI#

You can also create an ITS using the KubeFlex CLI:

kflex create its1 --type vcluster -p ocm

KubeFlex Hosting Cluster as ITS#

The KubeFlex hosting cluster can be configured to act as an ITS by specifying type: host when creating the ITS:

helm upgrade --install ks-core oci://ghcr.io/kubestellar/kubestellar/core-chart \
  --set-json='ITSes=[{"name":"its1", "type":"host"}]'

This approach: - Avoids creating a separate virtual cluster - Simplifies the architecture by reusing the hosting cluster - Makes the ITS directly accessible through the hosting cluster's API server

Important Note on ITS Registration#

Creating an ITS includes installing the relevant OCM (Open Cluster Management) machinery in it. However, registering the ITS as a KubeFlex control plane is a separate step that happens automatically when using the Core Helm Chart or KubeFlex CLI with the appropriate parameters.

Architecture and Components#

The ITS runs the OCM Cluster Manager, which: - Accepts registrations from WECs through the OCM registration agent - Manages the distribution of workloads to WECs - Maintains status information from the WECs - Creates and manages mailbox namespaces for each registered WEC