The kamino project is a collection of Kubernetes cluster tools designed to support and optimize "pools" of nodes. We define a pool as a collection of Kubernetes nodes built according to a common requirement spec. Under the hood, those nodes are implemented as VMs built according to a common recipe and scaled out or in by some cloud provider "VM factory" service (for example, Virtual Machine Scale Sets in Azure, Auto Scaling using AWS).
Put simply: "identical", "peer" nodes that exist in duplicate for the purpose of rapid horizontal scaling.
The kamino set of tools are currently approaching a v1.0 stable release, tested against Kubernetes running on Azure with VMSS-backed node pools, on clusters built with the AKS Engine tool.
More status here.
We encourage folks who are using the above stated, known-working Kubernetes + Azure foundations to experiment and report back any issues, or request additional functionality that will help your existing node set use cases:
The kamino project publishes a Helm Chart called "vmss-prototype". You may use that Chart to take a snapshot of the OS image from one instance in your VMSS node pool, and then update the VMSS model definition so that future instances (nodes) use that image snapshot. For example:
$ helm install --repo https://jackfrancis.github.io/kamino/ \
update-vmss-model-image-from-instance-0 \
vmss-prototype --namespace default \
--set kamino.scheduleOnControlPlane=true \
--set kamino.targetNode=k8s-pool1-12345678-vmss000000The above will create a helm release update-vmss-model-image-from-instance-0, which will create a job with the same name in the default Kubernetes namespace if a few assumptions are true:
- You run the above helm command in an execution context where the
KUBECONFIGenvironment variable is set to the kubeconfig file that identifies a privileged connection to the Kubernetes cluster whose node pool you want to update. - The node
k8s-pool1-12345678-vmss000000is running in your cluster, backed by an Azure VMSS instance, and is in a Ready state.
We use the helm release name update-vmss-model-image-from-instance-0 only as a hypothetical example: you may choose any name you wish. Also, the targetNode value k8s-pool1-12345678-vmss000000 is entirely a hypothetical example: make sure you use a value that correlates with an actual node that was created by an Azure VMSS that you want to update.
If you're not familiar with using helm tool to manage Kubernetes resource deployments, lots of good docs are here:
A complete walkthrough of using vmss-prototype on a cluster is here.
More detailed information on vmss-prototype is here.