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# Copyright (c) 2009-2011, Eucalyptus Systems, Inc.
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# Redistribution and use of this software in source and binary forms, with or
# without modification, are permitted provided that the following conditions
# are met:
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#   Redistributions of source code must retain the above
#   copyright notice, this list of conditions and the
#   following disclaimer.
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#   materials provided with the distribution.
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# Author: Neil Soman neil@eucalyptus.com
#         Mitch Garnaat mgarnaat@eucalyptus.com

from boto.utils import get_instance_metadata
from exceptions import MetadataReadError

class MetaData(object):

    def __init__(self):
        self.md = get_instance_metadata()
        
    def get_instance_metadata(self, key):
        try:
            value = self.md[key]
        except KeyError:
            raise MetadataReadError
        return value

    def get_instance_ramdisk(self):
        return self.get_instance_metadata('ramdisk-id')

    def get_instance_kernel(self):
        return self.get_instance_metadata('kernel-id')

    def get_instance_product_codes(self):
        return self.get_instance_metadata('product-codes')

    def get_ancestor_ami_ids(self):
        return self.get_instance_metadata('ancestor-ami-ids')

    def get_instance_block_device_mappings(self):
        return self.get_instance_metadata('block-device-mapping')