Modifying onboarded VANs with the Skupper CLI

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After you onboard an existing Red Hat® Service Interconnect® VAN as a Mesh network segment, you can use the Skupper CLI to modify the VAN. The changes are automatically discovered and the updated configuration is applied within Mesh.

Terminology used in Mesh and Red Hat Service Interconnect

The following table provides a mapping of equivalent terms in Mesh and Red Hat Service Interconnect:
Mesh Red Hat Service Interconnect
Network segment Virtual application network (VAN)
Gateway Site
Remote connection Link

Modify network segments

The primary methods of modifying Mesh network segments are by using the Mesh console and the Mesh CLI. However, for VANs that were onboarded as Mesh network segments, you can also use the Skupper CLI to make the following changes:
  • Add a Red Hat Service Interconnect site to the VAN.
  • Add or delete links between the sites in the VAN.
  • Expose or unexpose services in the VAN.
The Skupper CLI changes are automatically discovered and shown in Mesh.
Restriction: If you use the Skupper CLI to delete a site from the VAN, the changes are not discovered or shown in Mesh.

Don’t use the Skupper CLI to modify VANs that are associated with network segments that were created in Mesh. Those changes are not discovered or shown in Mesh.

Add or delete links with the Skupper CLI

When you use the Skupper CLI to add or delete links from an onboarded VAN, the changes are automatically discovered and the configuration updates are applied within Mesh.

If you add a link between the sites in the VAN, a remote connection is automatically created in Mesh to represent the link.

If you delete a link, the corresponding remote connection is deleted from Mesh.

Expose or unexpose services with the Skupper CLI

When you use the Skupper CLI to expose or unexpose services in the onboarded VAN, the changes are automatically discovered and the configuration updates are applied to the relevant Mesh network segment.

Exposing services

If you expose a service, a connection policy is created in Mesh that represents how the service is exposed in the VAN.

If the service-sync property in the site ConfigMap is set to false, ensure that a proxy service exists on another site in the VAN to enable communication with the service. If a proxy service doesn’t exist, Mesh does not create a connection policy.
What is a proxy service: In Red Hat Service Interconnect, a service is considered a proxy service when it uses the following Kubernetes annotations: 
skupper.io/ingress-only=''
skupper.io/proxy=[tcp|http|http2]
skupper.io/port=<proxy-port>
skupper.io/address=<proxy-address>
Unexposing services

If you unexpose a service, the associated connection policy is deleted from Mesh.

Similarly, if the service-sync property is set to false and all proxy services that are linked to the service are deleted, the associated connection policy is also deleted from Mesh.

Add sites with the Skupper CLI and onboard to Mesh

After you use the Skupper CLI to add a site to an onboarded VAN, you must onboard the new site to Mesh. To start the onboarding, use the Mesh CLI to install an Open Horizon agent. A new unmanaged Red Hat Service Interconnect gateway is created automatically in Mesh. To complete the onboarding of the site, use the Mesh console to associate the gateway with a Mesh cluster.

Complete the following steps:

  1. Create a site by using the Skupper CLI.
  2. Associate the new site with an onboarded VAN by using the Skupper CLI to create links between the new site and other sites in the VAN.
    Note: If the new site is not linked to another site in a VAN, Mesh cannot determine the network segment to which the site belongs. As a result, the site is onboarded to a new network segment that includes only the new site.
  3. Install an Open Horizon agent for each site that you are onboarding. See Installing an Open Horizon agent.

    The agent is installed in the site's namespace and a Red Hat Service Interconnect gateway is automatically registered in Mesh.

    The Mesh Manager detects that the gateway relates to an existing network segment. The new gateway is listed on the Unmanaged gateways tab on the Gateways list page.

  4. Use the Mesh console to associate the gateway with a Mesh cluster.

    On the Gateways list page, click Associate cluster for the new gateway.

  5. Select a cluster and an application group and click Select.

    After a gateway is successfully connected to a cluster, all applications within the namespace are automatically discovered and registered into the application group that you select.

    Mesh also creates remote connections to represent links between the new site and the other sites in the VAN.

  6. Check that the site was onboarded and the new gateway is functioning correctly as part of the Red Hat Service Interconnect deployment:
    • View the new gateway on the Gateways page and the Network segment details page.
    • Use the Topology view to visualize the relationships between the new gateway and the other resources in the network segment. The resources include locations, deployment environments, other gateways, and associated applications and services.

  7. Check whether any events were created during the onboarding of the site by viewing the Events page in the Mesh console.

    For example, you might see the following events:
    • If a flow collector is not installed for at least one site in the VAN, metrics collection is not enabled. A no flow collector was found at any site event is created.
    • If the sites in the VAN have different values for the service-sync property, the onboarding fails to complete and a Service Sync was not consistent across all sites event is created.