# Functions
GetSigner returns an ssh.Signer for the provider ("gce", etc.) that can be used to SSH to their nodes.
IssueSSHCommand tries to execute a SSH command.
IssueSSHCommandWithResult tries to execute a SSH command and returns the execution result.
LogResult records result log.
NodeExec execs the given cmd on node via SSH.
NodeSSHHosts returns SSH-able host names for all schedulable nodes - this excludes master node.
SSH synchronously SSHs to a node running on provider and runs cmd.