Peer to a foreign cluster

Once Liqo is installed in your cluster, you can start establishing new peerings. Specifically, you can rely on three different methods to peer with other clusters:

  1. LAN Discovery: automatic discovery of neighboring clusters available in the same LAN. This looks similar to the automatic discovery of Wi-Fi hotspots and it is particularly suitable when your cluster is composed of a single node (e.g., K3s).
  2. DNS Discovery: automatic discovery of the clusters associated with a specific DNS domain (e.g.; liqo.io), by scraping the existence of specific DNS entries. This looks similar to the discovery of voice-over-IP SIP servers and it is mostly oriented to big organizations that wish to adopt Liqo in production.
  3. Manual Configuration: manual addition of specific clusters to the list of known ones. This method is particularly appropriate outside LAN, without requiring any DNS configuration.

In this tutorial, we rely on LAN Discovery since our Kind clusters are in the same L2 broadcast domain.

LAN Discovery

Liqo can automatically discover any available clusters or make any clusters discoverable on the same LAN.

Using kubectl, you can also manually obtain the list of discovered foreign clusters:

kubectl get foreignclusters
NAME                                   AGE
ff5aa14a-dd6e-4fd2-80fe-eaecb827cf55   101m

The foreigncluster object is used in Liqo to model remote clusters discovered.

To check whether Liqo attempts to peer with the foreign cluster automatically, you can check the join property of the specific ForeignCluster resource:

kubectl get foreignclusters ${FOREIGN_CLUSTER} --template={{.spec.join}}
true

Peering checking

Presence of the virtual-node

If the peering has succeded, you should see a virtual node (named liqo-*) in addition to your physical nodes:

kubectl get nodes

NAME                                      STATUS   ROLES
master-node                               Ready    master
worker-node-1                             Ready    <none>
worker-node-2                             Ready    <none>
liqo-9a596a4b-591c-4ac6-8fd6-80258b4b3bf9 READY    agent    <-- This is the virtual node

Verify that the resulting infrastructure works correctly

You are now ready to verify that the resulting infrastructure works correctly, presented in the next step.