- conf.d rather than 'opt_include' (or #include)
- consider 'failsafe' DataSource
  If all others fail, setting a default that
   - sets the user password, writing it to console
   - logs to console that this happened
- consider 'previous' DataSource
  If no other data source is found, fall back to the 'previous' one
  keep a indication of what instance id that is in /var/lib/cloud
- rewrite "cloud-init-query"
  have DataSource and cloudinit expose explicit fields
   - instance-id
   - hostname
   - mirror
   - release
   - ssh public keys