Address Allocation exception

[Marian Neagul]

An error should be raised when not enought resources are available for allocating a new address, and any provisioned resources should be released (Kill nodes).

At this point the client just dies (as in the following example) and leaves resources in "limbo":

Traceback (most recent call last):
  File "/Users/mneagul/bin/sct-cli", line 9, in <module>
    load_entry_point('sct==0.0.1', 'console_scripts', 'sct-cli')()
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cli.py", line 306, in main
    args.func(args)
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cli.py", line 67, in __args_wrapper
    print func(**passed_args)
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cluster.py", line 245, in add_node
    keypair_name=keypair_name, userdata=user_data)
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cloud.py", line 195, in create_node
    addr = self.associate_address(instance_id=node.extra['instance_id'])
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cloud.py", line 395, in associate_address
    requested_address = self.get_address()
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cloud.py", line 373, in get_address
    address = self.allocate_address()
  File "/Users/mneagul/IdeaProjects/SCAPECloudToolkit/src/sct/cloud.py", line 353, in allocate_address
    response = self.conn.ex_allocate_address()
  File "/Users/mneagul/sdks/scape/lib/python2.7/site-packages/apache_libcloud-0.14.0-py2.7.egg/libcloud/compute/drivers/ec2.py", line 2457, in ex_allocate_address
    response = self.connection.request(self.path, params=params).object
  File "/Users/mneagul/sdks/scape/lib/python2.7/site-packages/apache_libcloud-0.14.0-py2.7.egg/libcloud/common/base.py", line 675, in request
    response = responseCls(**kwargs)
  File "/Users/mneagul/sdks/scape/lib/python2.7/site-packages/apache_libcloud-0.14.0-py2.7.egg/libcloud/common/base.py", line 112, in __init__
    raise Exception(self.parse_error())
Exception: AllocateAddressType: InsufficientAddressCapacity