GKE Autopilot: Multicluster gateway: What commands to use to switch to another configuration cluster

[g3289ds]

https://cloud.google.com/kubernetes-engine/docs/how-to/enabling-multi-cluster-gateways#enable_multi-... and

https://cloud.google.com/kubernetes-engine/docs/how-to/multi-cluster-ingress-setup#specifying_a_conf...show how to enable multi-cluster gateway and specify the config cluster with this (example) command:

gcloud container fleet ingress enable \
    --config-membership=projects/PROJECT_ID/locations/us-west1-a/memberships/gke-west-1 \
    --project=PROJECT_ID

But I fail to where in the documentation that shows the proper way change to a new configuration cluster. Documentation for the command doesn't explain this either: https://cloud.google.com/sdk/gcloud/reference/container/fleet/ingress/enable

Will running the command and specifying --config-membership with a different cluster automatically start transfer process? Are there any consequences not disabling fleet ingress on after/before switching? Other documentation suggests manually specifying MultiClusterIngress/MultiClusterService resource yaml. But if it is the case that I would need to use the yaml what would I use to base the yaml on since gcloud container fleet ingress enable ... --config-membership=... doesn't add MultiClusterIngress/MultiClusterService to yaml?

[LeAnt]

Hi @g3289ds 

Welcome to Google Cloud Community! Below are the answers to your questions.

Q: Will running the command and specifying --config-membership for a different cluster, automatically start the transfer process? 

A: Running that command and specifying --config-membership for a different cluster does not automatically start the transfer process. Multi-Cluster Gateway is a routing tool. It sets up the framework for managing traffic across clusters, but you'll need to define how traffic is routed. You can refer to this Google Cloud documentation as well as this third-party documentation for additional information.

Q: Will there be any consequence when fleet ingress is not disabled before or after switching?

A: Not disabling fleet ingress before or after switching clusters can have consequences, such as service disruption (conflicting routes and deployment issues) and security risks (unintended access and increased attack surface).

Q: What base yaml can I use if I want to manually specify MultiClusterIngress/MultiClusterService?

A: If you need to manually specify MultiClusterIngress/MultiClusterService resources using yaml, you would base your yaml on the provided examples in this documentation, because the command gcloud container fleet ingress enable ... does not directly add these resources to yaml files. For best practices and detailed information on managing ingress in GKE Autopilot, refer to the official GKE documentation.

I hope this information is helpful.

If you need further assistance, you can always file a ticket with our support team.