[Enhancement] Add missing fields / endpoints to Images + Servers about hcloud-ruby

[RaphaelPour]

Server also as a bunch of more attributes:

• id
• created
• image
• server_type
• datacenter
• included_traffic
• ingoing_traffic
• outgoing_traffic
• locked
• name
• primary_disk_size
• rescue_enabled
• status
• backup_window
• iso
• labels (currently hash)
• load_balancers (currently array)
• placement_group
• private_net (currently array)
• protection ({"delete"=>false, "rebuild"=>false})
• public_net (currently hash)
• volumes (currently list)

At least load_balancers, private_net, public_net and volumes are collections of resources. The schema defined in entry_loader.rb maps the api response to objects, can't handle collections AFAIK. Either we extend the schema, create a collection resource for each one (VolumesCollection containing Volume objects) or create a generic Collection than can be initialized with the wanted resource schema(volumes: Collection(Volume)).

Went through the API docs and the code and found the following missing actions:

• Network
  • change_ip_range
• Server
  • Get metrics
  • add_to_placement_group
  • change_alias_ips
  • change_dns_ptr
  • remove_from_placement_group

The following attributes on existing actions are missing

• Firewall
  • labels on update
• Floating IPs
  • name on create
  • name, labels on update
• Image
  • status, include_deprecated on get all
  • labels on update
• Network
  • labels on update
• Placement Groups
  • label_selector on get all
  • labels on update
• Server
  • automount, firewalls, placement_group, public_net, volumes on create
  • labels on update
• SSH key
  • fingerprint on get all
  • labels on update
• Volume
  • status on get all
  • labels on update

It's probably good that the labels fields on :updatable are missing. I just checked what this does, because update(labels: {'foo': 'bar'}) works without problems. :updatable creates attr= methods, so fields can be changed with obj.name = 'new-name'. The changes can then be persisted using obj.save:

obj = client.load_balancers['old-name']
obj.name = 'new-name'
obj.save
# besides: call to save is currently broken, so nobody uses this feature

# alternative (which works):
obj.update({ name: 'new-name' })

For labels being a hash this does not work as expected (at least as I as a user would want to use it). The following code does not save the new label to the Cloud API.

obj = client.load_balancers['old-name']
obj.labels.merge({ 'label' => 'value' })
obj.save

tl;dr: I think we'll have to think a bit more about :updatable to make it work with objects (like hashes) that can be changed in other ways than assignments.