How to grow my cluster in Google Container Engine / Kubernetes?

Question

I have two instances of the application container (this is the Node.JS application, but it does not matter) running in the Kubernetes cluster in the Google Container Engine. I would like to increase it to three copies.

My cluster has a master and two junior nodes with a replication controller and a load balancer. The replication controller supports my two-node application container.

I see that there is a handy gcloud alpha container kubectl resize command that allows me to change the number of replicas, but I don’t see how or if I can increase the cluster size so that it can deploy another Node minion. I only see gcloud commands to create, delete, list and describe clusters; nothing to change them.

If I cannot resize my cluster, then for scaling I need to create a whole new cluster and kill the old one. Did I miss something?

Also, do you plan to support autoscaling?

Answer 1

Update (June 2015): Kubernetes on GCE now uses managed instance groups, which you can manually modify to add new nodes to your cluster.

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There is currently no way to add nodes to an existing Google Container Engine cluster. We are currently adding Kubernetes support so that clusters add dynamically added nodes , but work has not yet been completed. Once a feature is available in Kubernetes, you can expect it to appear in the Google Container Engine shortly after the next Kubernetes release.

At the same time, it should be possible to run more than two replicas of your node.js application on the existing two virtual machines.

Answer 2

This presentation: http://fr.slideshare.net/craigbox/autoscaling-kubernetes - about horizontal scaling of tunnels in the Google cloud. I put this link here to save some googling to the next one that ends in this thread.