Avi Multi-Cloud Support for Multiple OpenShift/Kubernetes Clusters
As of release 17.2.5, a single Avi Controller cluster can support multiple OpenShift/K8S clusters. [Here we’ve used the word “cluster” used in two different senses.] This is achieved by setting the case-sensistive
cluster_tag parameter in the Avi cloud configuration for each OpenShift/Kubernetes cluster. This permits tenants and/or objects to be similarly named, but nonetheless are isolated to avoid any overlap in the configuration. This feature can only be accessed via the Avi REST API or Avi CLI as of the writing of this article.
In the below command-line sequence, three distinct OS/K8S clusters are tagged
PaloAlto) and associated with individual Avi cloud names (
[controller]> configure cloud avi-cloud-santaclara oshiftk8s_configuration cluster_tag SantaClara save save [controller]> configure cloud avi-cloud-sanjose oshiftk8s_configuration cluster_tag SanJose save save [controller]> configure cloud avi-cloud-paloalto oshiftk8s_configuration cluster_tag PaloAlto save save
Qualifying Identically Named Tenants
Use of the
cluster_tag parameter is essential when OS/K8S tenants are similarly named, as illustrated in figure 1. As for tenants in the first OpenShift/K8S cloud, no qualification is required when first defined, as they are the only OS/K8S tenants in the Avi configuration. Consequently, in the below screenshot of a two-cloud environment, you see unqualified tenant names such as
logging. However, as soon as the second Avi cloud is created for a second Kubernetes cluster, the verbatim same tenant names don’t work. They are formed by appending an at-sign (@) followed by the cluster_tag (
Santa Clara) to the names with which they’d otherwise clash.
If multiple applications have the same name in identically named tenants, you can disable auto-assigning of FQDNs by the Avi Controller as illustrated below. In addition, ensure the FQDNs provided are unique.
[controller]> configure cloud avi-cloud-santaclara oshiftk8s_configuration no auto_assign_fqdn save save
Note: Starting with Avi Vantage release 18.2.2, you can disable this option from the UI. Navigate to Edit Cloud > Applications, and disable the option Auto Assign FQDN.