Infrastructure

There is a need for a consistent way to define the root of each environment. Given the Root URL of a DataONE environment, a client can discover all it needs to know to interact with services available there. e.g. For the sandbox environment, a client may connect to "cn-sandbox.dataone.org" which should point to one of the sandbox CN implementations. From that, the client could pull the node registry and discover nodes and services available in that environment.

suggest:

Production: cn.dataone.org (RR DNS pointing to one of cn-ucsb-1, cn-unm-1, or cn-orc-1)
Staging: cn-staging.dataone.org
Sandbox: cn-sandbox.dataone.org
Development: cn-dev.dataone.org

Client instances should take a CN address as a parameter, this would be something that resolves to a CN baseURL, which could be a direct link to a CN, or an indirect link via the RR DNS mechanism.