
By setting KUBE_SHARE_MASTER=true we reuse an existing master, rather than creating a new one. By setting KUBE_SUBNET_CIDR=172.20.1.0/24 you can specify the CIDR for a new subnet, avoiding conflicts. Both these options are documented only in kube-up and clearly marked as 'experimental' i.e. likely to change. By combining these, you can kube-up a cluster normally, and then kube-up a cluster in a different AZ, and the new nodes will attach to the same master. KUBE_SHARE_MASTER is also useful for addding a second node auto-scaling-group, for example if you wanted to mix spot & on-demand instances.
Cluster Configuration
The scripts and data in this directory automate creation and configuration of a Kubernetes cluster, including networking, DNS, nodes, and master components.
See the getting-started guides for examples of how to use the scripts.
cloudprovider/config-default.sh
contains a set of tweakable definitions/parameters for the cluster.
The heavy lifting of configuring the VMs is done by SaltStack.