Cloud Connector to AKO Migration
Cloud connector(CC) is not supported from Avi Controller version 20.1 onwards. To migrate the existing workload present in a Kubernetes cluster from Avi Controller running the OpenShift/Kubernetes cloud using cloud connector to AKO based Avi Controller, following two features are used:
Namespace-Driven Inclusion/Exclusion of OpenShift/Kubernetes Applications
For migration, the exclusion feature allows ingresses/routes from specific namespace(s) to be deleted(excluded) from the Avi Controller. For that, the namespace has to be labelled with the same key:value pair as that of exclude attribute and exclude value mentioned in cloud. This feature is supported in Avi Controller running the OpenShift/Kubernetes cloud using cloud connector.
For details about how to use exclusion feature, refer to Namespace-Driven Inclusion/Exclusion of OpenShift/Kubernetes Applications.
The Namespace Sync feature
This feature is supported by AKO starting with AKO version 1.4.1.
The namespace sync feature allows Kubernetes objects from specific namespace to be synced with an AKO based Avi Controller. For that, the namespace has to be labelled with same key:value pair as that labelKey and labelValue mentioned in values.yaml file.
For more information, refer to Namespace Sync in AKO.
This migration activity is currently supported for vCenter cloud with Kubernetes based workloads.
This section explains the steps of migration
- Setup a new Controller (compatible with AKO version 1.4.1 and above)
- Setup a new vCenter cloud with write access
- Setup an IPAM on vCenter cloud. It is recommended to configure IPAM on vCenter cloud with non-overlapping usable network to avoid IP address conflict or non-availability of IP address after migration
- Setup a DNS Service on vCenter cloud
- Replicate the Avi side objects, referred by Ingresses/Services as part of AVI_PROXY annotations, to the new Controller.
- Ensure the AKO version is 1.4.1 and above.
Deploying AKO CRDs
For each AVI_PROXY annotation present in an ingress, create the corresponding AKO Http rule/Host rule/ AviInfrasetting rule. For more information, refer to Setting up Routing Rules using CRDs .
If any AVI_PROXY annotation is not supported by these CRDs, then the virtual service which is migrated to AKO based Avi Controller will not have same features as that as the Avi Controller running the OpenShift/Kubernetes cloud using cloud connector.
Note: List of AVI_PROXY annotations supported by AKO CRDs will be published soon.
With AKO, the SEs are deployed outside the Kubernetes cluster. So deploy AKO with static routing set to
false depending upon the POD network reachability and with namespace sync feature enabled.
# NamespaceSelector contains label key and value used for namespacemigration
# Same label has to be present on namespace/s which needs migration/sync to AKO
As an example, AKO is deployed with app as a key and migrate as a value for namespace selector. So AKO will sync up all objects from namespace(s) which has this label and corresponding Avi objects will be created in the Avi Controller.
Excluding Namespace-Driven OpenShift/Kubernetes Applications
Set an exclude attribute and exclude value for Openshift/Kubernetes cloud either from the Avi UI or the AvI shell.
The key and value should be same as mentioned in values.yaml of AKO.
Set up an exclude attribute and exclude value using the UI as shown below:
Set up an exclude attribute and exclude value using Avi shell:
[admin:cc-controller-host-name]: > configure cloud Default-Cloud
[admin:cc-controller-host-name]: cloud> oshiftk8s_configuration
[admin:cc-controller-host-name]: cloud:oshiftk8s_configuration> ns_exclude_attributes
[admin:cc-controller-host-name]: cloud:oshiftk8s_configuration:ns_exclude_attributes> attribute app
[admin:cc-controller-host-name]: cloud:oshiftk8s_configuration:ns_exclude_attributes> value migrate
[admin:cc-controller-host-name]: cloud:oshiftk8s_configuration:ns_exclude_attributes> save
[admin:cc-controller-host-name]: cloud:oshiftk8s_configuration> save
[admin:cc-controller-host-name]: cloud> save
In this example, the exclude attribute is set as app and the exclude value is set as migrate. This deletes virtual services of namespace(s), which has same label, from the Avi Controller running the OpenShift/Kubernetes cloud using cloud connector.
Setting Kubernetes Namespace Label
Label namespace(s) in a Kubernetes cluster with the same key:value pair.
As shown in the example, the “red” namespace is labelled with “app: migrate”. This will result in deletion of virtual services of red namespace from the Avi Controller running the OpenShift/Kubernetes cloud using the cloud connector and creation of new virtual services for red namespace in AKO-based Avi Controller.
Note: There will be traffic disruption during migration.
The newly created objects in an AKO-based Avi Controller may get new VIPs. Hence, the internal traffic tests need to be performed for migrated applications.
After successful testing, migrate objects from other namespaces by labelling the namespace one by one.
Redirecting Client Traffic
After migrating all the L4-L7 applications to an AKO-based Avi Controller, the client traffic can be redirected to new VIPs by one of the following ways:
Change DNS server entry in corporate DNS server to point to new DNS service on the AKO-based Avi Controller
Change IP address of DNS service running on AKO based Avi Controller with IP address of DNS service present on Avi Controller running the OpenShift/Kubernetes cloud using the cloud connector if IPAM from both clouds have overlapping subnets.
Cleaning Up of Cloud Connector (OpenShift Cloud)
After migrating all the Kubernetes objects, the old OpenShift/Kubernetes cloud can be deleted.