nicer error messages for missing required params on models

lib/fog/aws/models/ec2/address.rb

@@ -9,11 +9,15 @@ module Fog
         attribute :instance_id, 'instanceId'
 
         def destroy
+          requires :public_ip
+
           connection.release_address(@public_ip)
           true
         end
 
         def instance=(new_instance)
+          requires :public_ip
+
           if new_instance
             associate(new_instance)
           else

lib/fog/aws/models/ec2/instance.rb

@@ -24,10 +24,14 @@ module Fog
         attribute :user_data
 
         def addresses
+          requires :instance_id
+
           connection.addresses(:instance => self)
         end
 
         def destroy
+          requires :instance_id
+
           connection.terminate_instances(@instance_id)
           true
         end
@@ -41,6 +45,8 @@ module Fog
         # end
 
         def key_pair
+          requires :key_name
+
           connection.keypairs.all(@key_name).first
         end
 
@@ -65,11 +71,15 @@ module Fog
         end
 
         def reboot
+          requires :instance_id
+
           connection.reboot_instances(@instance_id)
           true
         end
 
         def save
+          requires :image_id
+
           options = {}
           if @availability_zone
             options['Placement.AvailabilityZone'] = @availability_zone
@@ -101,6 +111,8 @@ module Fog
         end
 
         def volumes
+          requires :instance_id
+
           connection.volumes(:instance => self)
         end
 

lib/fog/aws/models/ec2/key_pair.rb

@@ -10,11 +10,15 @@ module Fog
         attribute :material,    'keyMaterial'
 
         def destroy
+          requires :name
+
           connection.delete_key_pair(@name)
           true
         end
 
         def save
+          requires :name
+
           data = connection.create_key_pair(@name).body
           new_attributes = data.reject {|key,value| !['keyFingerprint', 'keyMaterial', 'keyName'].include?(key)}
           merge_attributes(new_attributes)

lib/fog/aws/models/ec2/security_group.rb

@@ -11,6 +11,8 @@ module Fog
         attribute :owner_id,          'ownerId'
 
         def authorize_group_and_owner(group, owner)
+          requires :group_name
+
           connection.authorize_security_group_ingress(
             'GroupName'                   => @group_name,
             'SourceSecurityGroupName'     => group,
@@ -19,6 +21,8 @@ module Fog
         end
 
         def authorize_port_range(range, options = {})
+          requires :group_name
+
           connection.authorize_security_group_ingress(
             'CidrIp'      => options[:cidr_ip] || '0.0.0.0/0',
             'FromPort'    => range.min,
@@ -29,11 +33,15 @@ module Fog
         end
 
         def destroy
+          requires :group_name
+
           connection.delete_security_group(@group_name)
           true
         end
 
         def save
+          requires :group_name
+
           data = connection.create_security_group(@group_name, @group_description).body
           true
         end

lib/fog/aws/models/ec2/snapshot.rb

@@ -12,18 +12,24 @@ module Fog
         attribute :volume_id,    'volumeId'
 
         def destroy
+          requires :snapshot_id
+
           connection.delete_snapshot(@snapshot_id)
           true
         end
 
         def save
-          data = connection.create_snapshot(volume_id).body
+          requires :volume_id
+
+          data = connection.create_snapshot(@volume_id).body
           new_attributes = data.reject {|key,value| key == 'requestId'}
           merge_attributes(new_attributes)
           true
         end
 
         def volume
+          requires :snapshot_id
+
           connection.describe_volumes(@volume_id)
         end
 

lib/fog/aws/models/ec2/volume.rb

@@ -23,11 +23,15 @@ module Fog
         end
 
         def destroy
+          requires :volume_id
+
           connection.delete_volume(@volume_id)
           true
         end
 
         def instance=(new_instance)
+          requires :volume_id
+
           if new_instance
             attach(new_instance)
           else
@@ -36,6 +40,8 @@ module Fog
         end
 
         def save
+          requires :availability_zone, :size, :snapshot_id
+
           data = connection.create_volume(@availability_zone, @size, @snapshot_id).body
           new_attributes = data.reject {|key,value| key == 'requestId'}
           merge_attributes(new_attributes)
@@ -46,7 +52,9 @@ module Fog
         end
 
         def snapshots
-          connection.snapshots(:volume_id => volume_id)
+          requires :volume_id
+
+          connection.snapshots(:volume_id => @volume_id)
         end
 
         private

lib/fog/aws/models/s3/bucket.rb

@@ -10,6 +10,8 @@ module Fog
         attribute :owner
 
         def destroy
+          requires :name
+
           connection.delete_bucket(@name)
           true
         rescue Excon::Errors::NotFound
@@ -17,6 +19,8 @@ module Fog
         end
 
         def location
+          requires :name
+
           data = connection.get_bucket_location(@name)
           data.body['LocationConstraint']
         end
@@ -35,16 +39,22 @@ module Fog
         end
 
         def payer
+          requires :name
+
           data = connection.get_request_payment(@name)
           data.body['Payer']
         end
 
         def payer=(new_payer)
+          requires :name
+
           connection.put_request_payment(@name, new_payer)
           @payer = new_payer
         end
 
         def save
+          requires :name
+
           options = {}
           if @location
             options['LocationConstraint'] = @location

lib/fog/aws/models/s3/object.rb

@@ -20,6 +20,8 @@ module Fog
         end
 
         def copy(target_bucket_name, target_object_key)
+          requires :bucket, :key
+
           data = connection.copy_object(bucket.name, @key, target_bucket_name, target_object_key).body
           target_bucket = connection.buckets.new(:name => target_bucket_name)
           target_object = target_bucket.objects.new(attributes.merge!(:key => target_object_key))
@@ -34,11 +36,14 @@ module Fog
         end
 
         def destroy
+          requires :bucket, :key
+
           connection.delete_object(bucket.name, @key)
           true
         end
 
         def save(options = {})
+          requires :body, :bucket, :key
           data = connection.put_object(bucket.name, @key, @body, options)
           @etag = data.headers['ETag']
           true

lib/fog/model.rb

@@ -89,6 +89,20 @@ module Fog
       merge_attributes(new_attributes)
     end
 
+    def requires(*args)
+      missing = []
+      for arg in [:connection] | args
+        missing << arg unless send("#{arg}")
+      end
+      unless missing.empty?
+        if missing.length == 1
+          raise(ArgumentError, "#{missing.first} is required for this operation")
+        else
+          raise(ArgumentError, "#{missing[0...-1].join(", ")} and #{missing[-1]} are required for this operation")
+        end
+      end
+    end
+
     private
 
     def collection=(new_collection)

lib/fog/rackspace/models/servers/image.rb

@@ -13,15 +13,21 @@ module Fog
         attribute :server_id,   'serverId'
 
         def server=(new_server)
+          requires :id
+
           @server_id = new_server.id
         end
 
         def destroy
+          requires :id
+
           connection.delete_image(@id)
           true
         end
 
         def save
+          requires :server_id
+
           data = connection.create_server(@server_id)
           merge_attributes(data.body['image'])
           true

lib/fog/rackspace/models/servers/server.rb

@@ -18,20 +18,27 @@ module Fog
         attribute :metadata
 
         def destroy
+          requires :id
+
           connection.delete_server(@id)
           true
         end
 
         def images
+          requires :id
+
           connection.images(:server => self)
         end
 
         def reboot(type = 'SOFT')
+          requires :id
+
           connection.reboot_server(@id, type)
           true
         end
 
         def save
+          requires :flavor_id, :image_id, :name
           options = { 'metadata' => @metadata, 'personality' => @personality }
           options = options.reject {|key, value| value.nil?}
           data = connection.create_server(@flavor_id, @image_id, @name, options)