Auto-generate a new private network on creating a new performance cluster

[kenperkins]

There are two main use cases for coreos-cluster:

1. Creating a new cluster
2. Expanding an existing cluster

In the case of a new cluster, we should expose the option of creating a new private network, or using an existing private network guid. Whether or not you create a new network, or using an existing one, we'll store metadata on each server created with the guid of the private network connected. This comes into play in the expanding an existing cluster case.

In the case of expanding the existing cluster, we'll simply look up the metadata on the existing nodes, and if a private network guid is found in the metadata, we'll connect the new nodes to this network.

So I foresee two valid options for creating your cluster:

New Network

{
  privateNetwork: true
  // other options
}

Existing Network

{
  privateNetwork: 'some-guid-to-your-private-network'
  // other options
}

Edit: clarified the description

[rosskukulinski]

@kenperkins do you supporting passing in an existing etcd key?

I sorta foresee two use cases:

1. You want to generate a fresh cluster with a unique etcd & private network
2. You want to add more systems to an existing cluster (and thus re-use etcd & network)

[kenperkins]

@rosskukulinski yes we allow expanding an existing cluster.

[kenperkins]

It's the discovery-service-url option here: https://github.com/kenperkins/coreos-cluster#options

Example:

{
  // other options
  discoveryServiceUrl: 'https://discovery.etcd.io/efe2c719597730f5cb2c8d75b227eac2'
}

[rosskukulinski]

noted, thanks

[kenperkins]

Updated the bug description to be more accurate.