serializing cluster state

[mischief]

i'd like to be able to serialize cluster state and reconstitute it later. this means saving the platform, and the instance IDs into a json file.

however, it's currently not possible to save the SSH private key, because the ssh agent used in the platform code doesn't expose private keys.

a simple fix is to expose the private key in network.SSHAgent.

for this to work, these things need to be serializable and able to be created from serialized form -

• platform.Cluster
• platform.Machine
• network.SSHAgent

[peebs]

+1 on this concept. This lays the groundwork for taking a cluster setup by someone else and writing it into this serialized state for kola to then use.