rusoto_codegen 0.8.0

# Copyright 2012-2014 Amazon.com, Inc. or its affiliates. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
#
# http://aws.amazon.com/apache2.0/
#
# or in the "license" file accompanying this file. This file is
# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
# ANY KIND, either express or implied. See the License for the specific
# language governing permissions and limitations under the License.

from tests import unittest
from dateutil.tz import tzutc, tzoffset
import datetime
import six

import mock

from botocore import xform_name
from botocore.compat import OrderedDict, json
from botocore.awsrequest import AWSRequest
from botocore.exceptions import InvalidExpressionError, ConfigNotFound
from botocore.exceptions import ClientError
from botocore.exceptions import InvalidDNSNameError, MetadataRetrievalError
from botocore.model import ServiceModel
from botocore.vendored import requests
from botocore.utils import remove_dot_segments
from botocore.utils import normalize_url_path
from botocore.utils import validate_jmespath_for_set
from botocore.utils import set_value_from_jmespath
from botocore.utils import parse_key_val_file_contents
from botocore.utils import parse_key_val_file
from botocore.utils import parse_timestamp
from botocore.utils import parse_to_aware_datetime
from botocore.utils import datetime2timestamp
from botocore.utils import CachedProperty
from botocore.utils import ArgumentGenerator
from botocore.utils import calculate_tree_hash
from botocore.utils import calculate_sha256
from botocore.utils import is_valid_endpoint_url
from botocore.utils import fix_s3_host
from botocore.utils import switch_to_virtual_host_style
from botocore.utils import instance_cache
from botocore.utils import merge_dicts
from botocore.utils import get_service_module_name
from botocore.utils import percent_encode_sequence
from botocore.utils import switch_host_s3_accelerate
from botocore.utils import deep_merge
from botocore.utils import S3RegionRedirector
from botocore.utils import ContainerMetadataFetcher
from botocore.model import DenormalizedStructureBuilder
from botocore.model import ShapeResolver
from botocore.config import Config


class TestURINormalization(unittest.TestCase):
    def test_remove_dot_segments(self):
        self.assertEqual(remove_dot_segments('../foo'), 'foo')
        self.assertEqual(remove_dot_segments('../../foo'), 'foo')
        self.assertEqual(remove_dot_segments('./foo'), 'foo')
        self.assertEqual(remove_dot_segments('/./'), '/')
        self.assertEqual(remove_dot_segments('/../'), '/')
        self.assertEqual(remove_dot_segments('/foo/bar/baz/../qux'),
                         '/foo/bar/qux')
        self.assertEqual(remove_dot_segments('/foo/..'), '/')
        self.assertEqual(remove_dot_segments('foo/bar/baz'), 'foo/bar/baz')
        self.assertEqual(remove_dot_segments('..'), '')
        self.assertEqual(remove_dot_segments('.'), '')
        self.assertEqual(remove_dot_segments('/.'), '/')
        self.assertEqual(remove_dot_segments('/.foo'), '/.foo')
        self.assertEqual(remove_dot_segments('/..foo'), '/..foo')
        self.assertEqual(remove_dot_segments(''), '')
        self.assertEqual(remove_dot_segments('/a/b/c/./../../g'), '/a/g')
        self.assertEqual(remove_dot_segments('mid/content=5/../6'), 'mid/6')
        # I don't think this is RFC compliant...
        self.assertEqual(remove_dot_segments('//foo//'), '/foo/')

    def test_empty_url_normalization(self):
        self.assertEqual(normalize_url_path(''), '/')


class TestTransformName(unittest.TestCase):
    def test_upper_camel_case(self):
        self.assertEqual(xform_name('UpperCamelCase'), 'upper_camel_case')
        self.assertEqual(xform_name('UpperCamelCase', '-'), 'upper-camel-case')

    def test_lower_camel_case(self):
        self.assertEqual(xform_name('lowerCamelCase'), 'lower_camel_case')
        self.assertEqual(xform_name('lowerCamelCase', '-'), 'lower-camel-case')

    def test_consecutive_upper_case(self):
        self.assertEqual(xform_name('HTTPHeaders'), 'http_headers')
        self.assertEqual(xform_name('HTTPHeaders', '-'), 'http-headers')

    def test_consecutive_upper_case_middle_string(self):
        self.assertEqual(xform_name('MainHTTPHeaders'), 'main_http_headers')
        self.assertEqual(xform_name('MainHTTPHeaders', '-'),
                         'main-http-headers')

    def test_s3_prefix(self):
        self.assertEqual(xform_name('S3BucketName'), 's3_bucket_name')

    def test_already_snake_cased(self):
        self.assertEqual(xform_name('leave_alone'), 'leave_alone')
        self.assertEqual(xform_name('s3_bucket_name'), 's3_bucket_name')
        self.assertEqual(xform_name('bucket_s3_name'), 'bucket_s3_name')

    def test_special_cases(self):
        # Some patterns don't actually match the rules we expect.
        self.assertEqual(xform_name('SwapEnvironmentCNAMEs'),
                         'swap_environment_cnames')
        self.assertEqual(xform_name('SwapEnvironmentCNAMEs', '-'),
                         'swap-environment-cnames')
        self.assertEqual(xform_name('CreateCachediSCSIVolume', '-'),
                         'create-cached-iscsi-volume')
        self.assertEqual(xform_name('DescribeCachediSCSIVolumes', '-'),
                         'describe-cached-iscsi-volumes')
        self.assertEqual(xform_name('DescribeStorediSCSIVolumes', '-'),
                         'describe-stored-iscsi-volumes')
        self.assertEqual(xform_name('CreateStorediSCSIVolume', '-'),
                         'create-stored-iscsi-volume')

    def test_special_case_ends_with_s(self):
        self.assertEqual(xform_name('GatewayARNs', '-'), 'gateway-arns')

    def test_partial_rename(self):
        transformed = xform_name('IPV6', '-')
        self.assertEqual(transformed, 'ipv6')
        transformed = xform_name('IPV6', '_')
        self.assertEqual(transformed, 'ipv6')


class TestValidateJMESPathForSet(unittest.TestCase):
    def setUp(self):
        super(TestValidateJMESPathForSet, self).setUp()
        self.data = {
            'Response': {
                'Thing': {
                    'Id': 1,
                    'Name': 'Thing #1',
                }
            },
            'Marker': 'some-token'
        }

    def test_invalid_exp(self):
        with self.assertRaises(InvalidExpressionError):
            validate_jmespath_for_set('Response.*.Name')

        with self.assertRaises(InvalidExpressionError):
            validate_jmespath_for_set('Response.Things[0]')

        with self.assertRaises(InvalidExpressionError):
            validate_jmespath_for_set('')

        with self.assertRaises(InvalidExpressionError):
            validate_jmespath_for_set('.')


class TestSetValueFromJMESPath(unittest.TestCase):
    def setUp(self):
        super(TestSetValueFromJMESPath, self).setUp()
        self.data = {
            'Response': {
                'Thing': {
                    'Id': 1,
                    'Name': 'Thing #1',
                }
            },
            'Marker': 'some-token'
        }

    def test_single_depth_existing(self):
        set_value_from_jmespath(self.data, 'Marker', 'new-token')
        self.assertEqual(self.data['Marker'], 'new-token')

    def test_single_depth_new(self):
        self.assertFalse('Limit' in self.data)
        set_value_from_jmespath(self.data, 'Limit', 100)
        self.assertEqual(self.data['Limit'], 100)

    def test_multiple_depth_existing(self):
        set_value_from_jmespath(self.data, 'Response.Thing.Name', 'New Name')
        self.assertEqual(self.data['Response']['Thing']['Name'], 'New Name')

    def test_multiple_depth_new(self):
        self.assertFalse('Brand' in self.data)
        set_value_from_jmespath(self.data, 'Brand.New', {'abc': 123})
        self.assertEqual(self.data['Brand']['New']['abc'], 123)


class TestParseEC2CredentialsFile(unittest.TestCase):
    def test_parse_ec2_content(self):
        contents = "AWSAccessKeyId=a\nAWSSecretKey=b\n"
        self.assertEqual(parse_key_val_file_contents(contents),
                         {'AWSAccessKeyId': 'a',
                          'AWSSecretKey': 'b'})

    def test_parse_ec2_content_empty(self):
        contents = ""
        self.assertEqual(parse_key_val_file_contents(contents), {})

    def test_key_val_pair_with_blank_lines(self):
        # The \n\n has an extra blank between the access/secret keys.
        contents = "AWSAccessKeyId=a\n\nAWSSecretKey=b\n"
        self.assertEqual(parse_key_val_file_contents(contents),
                         {'AWSAccessKeyId': 'a',
                          'AWSSecretKey': 'b'})

    def test_key_val_parser_lenient(self):
        # Ignore any line that does not have a '=' char in it.
        contents = "AWSAccessKeyId=a\nNOTKEYVALLINE\nAWSSecretKey=b\n"
        self.assertEqual(parse_key_val_file_contents(contents),
                         {'AWSAccessKeyId': 'a',
                          'AWSSecretKey': 'b'})

    def test_multiple_equals_on_line(self):
        contents = "AWSAccessKeyId=a\nAWSSecretKey=secret_key_with_equals=b\n"
        self.assertEqual(parse_key_val_file_contents(contents),
                         {'AWSAccessKeyId': 'a',
                          'AWSSecretKey': 'secret_key_with_equals=b'})

    def test_os_error_raises_config_not_found(self):
        mock_open = mock.Mock()
        mock_open.side_effect = OSError()
        with self.assertRaises(ConfigNotFound):
            parse_key_val_file('badfile', _open=mock_open)


class TestParseTimestamps(unittest.TestCase):
    def test_parse_iso8601(self):
        self.assertEqual(
            parse_timestamp('1970-01-01T00:10:00.000Z'),
            datetime.datetime(1970, 1, 1, 0, 10, tzinfo=tzutc()))

    def test_parse_epoch(self):
        self.assertEqual(
            parse_timestamp(1222172800),
            datetime.datetime(2008, 9, 23, 12, 26, 40, tzinfo=tzutc()))

    def test_parse_epoch_zero_time(self):
        self.assertEqual(
            parse_timestamp(0),
            datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc()))

    def test_parse_epoch_as_string(self):
        self.assertEqual(
            parse_timestamp('1222172800'),
            datetime.datetime(2008, 9, 23, 12, 26, 40, tzinfo=tzutc()))

    def test_parse_rfc822(self):
        self.assertEqual(
            parse_timestamp('Wed, 02 Oct 2002 13:00:00 GMT'),
            datetime.datetime(2002, 10, 2, 13, 0, tzinfo=tzutc()))

    def test_parse_gmt_in_uk_time(self):
        # In the UK the time switches from GMT to BST and back as part of
        # their daylight savings time. time.tzname will therefore report
        # both time zones. dateutil sees that the time zone is a local time
        # zone and so parses it as local time, but it ends up being BST
        # instead of GMT. To remedy this issue we can provide a time zone
        # context which will enforce GMT == UTC.
        with mock.patch('time.tzname', ('GMT', 'BST')):
            self.assertEqual(
                parse_timestamp('Wed, 02 Oct 2002 13:00:00 GMT'),
                datetime.datetime(2002, 10, 2, 13, 0, tzinfo=tzutc()))

    def test_parse_invalid_timestamp(self):
        with self.assertRaises(ValueError):
            parse_timestamp('invalid date')


class TestDatetime2Timestamp(unittest.TestCase):
    def test_datetime2timestamp_naive(self):
        self.assertEqual(
            datetime2timestamp(datetime.datetime(1970, 1, 2)), 86400)

    def test_datetime2timestamp_aware(self):
        tzinfo = tzoffset("BRST", -10800)
        self.assertEqual(
            datetime2timestamp(datetime.datetime(1970, 1, 2, tzinfo=tzinfo)),
            97200)


class TestParseToUTCDatetime(unittest.TestCase):
    def test_handles_utc_time(self):
        original = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(parse_to_aware_datetime(original), original)

    def test_handles_other_timezone(self):
        tzinfo = tzoffset("BRST", -10800)
        original = datetime.datetime(2014, 1, 1, 0, 0, 0, tzinfo=tzinfo)
        self.assertEqual(parse_to_aware_datetime(original), original)

    def test_handles_naive_datetime(self):
        original = datetime.datetime(1970, 1, 1, 0, 0, 0)
        expected = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(parse_to_aware_datetime(original), expected)

    def test_handles_string_epoch(self):
        expected = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(parse_to_aware_datetime('0'), expected)

    def test_handles_int_epoch(self):
        expected = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(parse_to_aware_datetime(0), expected)

    def test_handles_full_iso_8601(self):
        expected = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(
            parse_to_aware_datetime('1970-01-01T00:00:00Z'),
            expected)

    def test_year_only_iso_8601(self):
        expected = datetime.datetime(1970, 1, 1, 0, 0, 0, tzinfo=tzutc())
        self.assertEqual(parse_to_aware_datetime('1970-01-01'), expected)


class TestCachedProperty(unittest.TestCase):
    def test_cached_property_same_value(self):
        class CacheMe(object):
            @CachedProperty
            def foo(self):
                return 'foo'

        c = CacheMe()
        self.assertEqual(c.foo, 'foo')
        self.assertEqual(c.foo, 'foo')

    def test_cached_property_only_called_once(self):
        # Note: you would normally never want to cache
        # a property that returns a new value each time,
        # but this is done to demonstrate the caching behavior.

        class NoIncrement(object):
            def __init__(self):
                self.counter = 0

            @CachedProperty
            def current_value(self):
                self.counter += 1
                return self.counter

        c = NoIncrement()
        self.assertEqual(c.current_value, 1)
        # If the property wasn't cached, the next value should be
        # be 2, but because it's cached, we know the value will be 1.
        self.assertEqual(c.current_value, 1)


class TestArgumentGenerator(unittest.TestCase):
    def setUp(self):
        self.arg_generator = ArgumentGenerator()

    def assert_skeleton_from_model_is(self, model, generated_skeleton):
        shape = DenormalizedStructureBuilder().with_members(
            model).build_model()
        actual = self.arg_generator.generate_skeleton(shape)
        self.assertEqual(actual, generated_skeleton)

    def test_generate_string(self):
        self.assert_skeleton_from_model_is(
            model={
                'A': {'type': 'string'}
            },
            generated_skeleton={
                'A': ''
            }
        )

    def test_generate_scalars(self):
        self.assert_skeleton_from_model_is(
            model={
                'A': {'type': 'string'},
                'B': {'type': 'integer'},
                'C': {'type': 'float'},
                'D': {'type': 'boolean'},
                'E': {'type': 'timestamp'}
            },
            generated_skeleton={
                'A': '',
                'B': 0,
                'C': 0.0,
                'D': True,
                'E': datetime.datetime(1970, 1, 1, 0, 0, 0)
            }
        )

    def test_will_use_member_names_for_string_values(self):
        self.arg_generator = ArgumentGenerator(use_member_names=True)
        self.assert_skeleton_from_model_is(
            model={
                'A': {'type': 'string'},
                'B': {'type': 'integer'},
                'C': {'type': 'float'},
                'D': {'type': 'boolean'},
            },
            generated_skeleton={
                'A': 'A',
                'B': 0,
                'C': 0.0,
                'D': True,
            }
        )

    def test_will_use_member_names_for_string_values_of_list(self):
        self.arg_generator = ArgumentGenerator(use_member_names=True)
        # We're not using assert_skeleton_from_model_is
        # because we can't really control the name of strings shapes
        # being used in the DenormalizedStructureBuilder. We can only
        # control the name of structures and list shapes.
        shape_map = ShapeResolver({
            'InputShape': {
                'type': 'structure',
                'members': {
                    'StringList': {'shape': 'StringList'},
                }
            },
            'StringList': {
                'type': 'list',
                'member': {'shape': 'StringType'},
            },
            'StringType': {
                'type': 'string',
            }
        })
        shape = shape_map.get_shape_by_name('InputShape')
        actual = self.arg_generator.generate_skeleton(shape)

        expected = {'StringList': ['StringType']}
        self.assertEqual(actual, expected)

    def test_generate_nested_structure(self):
        self.assert_skeleton_from_model_is(
            model={
                'A': {
                    'type': 'structure',
                    'members': {
                        'B': {'type': 'string'},
                    }
                }
            },
            generated_skeleton={
                'A': {'B': ''}
            }
        )

    def test_generate_scalar_list(self):
        self.assert_skeleton_from_model_is(
            model={
                'A': {
                    'type': 'list',
                    'member': {
                        'type': 'string'
                    }
                },
            },
            generated_skeleton={
                'A': [''],
            }
        )

    def test_generate_scalar_map(self):
        self.assert_skeleton_from_model_is(
            model={
                'A': {
                    'type': 'map',
                    'key': {'type': 'string'},
                    'value':  {'type': 'string'},
                }
            },
            generated_skeleton={
                'A': {
                    'KeyName': '',
                }
            }
        )

    def test_handles_recursive_shapes(self):
        # We're not using assert_skeleton_from_model_is
        # because we can't use a DenormalizedStructureBuilder,
        # we need a normalized model to represent recursive
        # shapes.
        shape_map = ShapeResolver({
            'InputShape': {
                'type': 'structure',
                'members': {
                    'A': {'shape': 'RecursiveStruct'},
                    'B': {'shape': 'StringType'},
                }
            },
            'RecursiveStruct': {
                'type': 'structure',
                'members': {
                    'C': {'shape': 'RecursiveStruct'},
                    'D': {'shape': 'StringType'},
                }
            },
            'StringType': {
                'type': 'string',
            }
        })
        shape = shape_map.get_shape_by_name('InputShape')
        actual = self.arg_generator.generate_skeleton(shape)
        expected = {
            'A': {
                'C': {
                    # For recurisve shapes, we'll just show
                    # an empty dict.
                },
                'D': ''
            },
            'B': ''
        }
        self.assertEqual(actual, expected)


class TestChecksums(unittest.TestCase):
    def test_empty_hash(self):
        self.assertEqual(
            calculate_sha256(six.BytesIO(b''), as_hex=True),
            'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')

    def test_as_hex(self):
        self.assertEqual(
            calculate_sha256(six.BytesIO(b'hello world'), as_hex=True),
            'b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9')

    def test_as_binary(self):
        self.assertEqual(
            calculate_sha256(six.BytesIO(b'hello world'), as_hex=False),
            (b"\xb9M'\xb9\x93M>\x08\xa5.R\xd7\xda}\xab\xfa\xc4\x84\xef"
             b"\xe3zS\x80\xee\x90\x88\xf7\xac\xe2\xef\xcd\xe9"))


class TestTreeHash(unittest.TestCase):
    # Note that for these tests I've independently verified
    # what the expected tree hashes should be from other
    # SDK implementations.

    def test_empty_tree_hash(self):
        self.assertEqual(
            calculate_tree_hash(six.BytesIO(b'')),
            'e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')

    def test_tree_hash_less_than_one_mb(self):
        one_k = six.BytesIO(b'a' * 1024)
        self.assertEqual(
            calculate_tree_hash(one_k),
            '2edc986847e209b4016e141a6dc8716d3207350f416969382d431539bf292e4a')

    def test_tree_hash_exactly_one_mb(self):
        one_meg_bytestring = b'a' * (1 * 1024 * 1024)
        one_meg = six.BytesIO(one_meg_bytestring)
        self.assertEqual(
            calculate_tree_hash(one_meg),
            '9bc1b2a288b26af7257a36277ae3816a7d4f16e89c1e7e77d0a5c48bad62b360')

    def test_tree_hash_multiple_of_one_mb(self):
        four_mb = six.BytesIO(b'a' * (4 * 1024 * 1024))
        self.assertEqual(
            calculate_tree_hash(four_mb),
            '9491cb2ed1d4e7cd53215f4017c23ec4ad21d7050a1e6bb636c4f67e8cddb844')

    def test_tree_hash_offset_of_one_mb_multiple(self):
        offset_four_mb = six.BytesIO(b'a' * (4 * 1024 * 1024) + b'a' * 20)
        self.assertEqual(
            calculate_tree_hash(offset_four_mb),
            '12f3cbd6101b981cde074039f6f728071da8879d6f632de8afc7cdf00661b08f')


class TestIsValidEndpointURL(unittest.TestCase):
    def test_dns_name_is_valid(self):
        self.assertTrue(is_valid_endpoint_url('https://s3.amazonaws.com/'))

    def test_ip_address_is_allowed(self):
        self.assertTrue(is_valid_endpoint_url('https://10.10.10.10/'))

    def test_path_component_ignored(self):
        self.assertTrue(
            is_valid_endpoint_url('https://foo.bar.com/other/path/'))

    def test_can_have_port(self):
        self.assertTrue(is_valid_endpoint_url('https://foo.bar.com:12345/'))

    def test_ip_can_have_port(self):
        self.assertTrue(is_valid_endpoint_url('https://10.10.10.10:12345/'))

    def test_cannot_have_spaces(self):
        self.assertFalse(is_valid_endpoint_url('https://my invalid name/'))

    def test_missing_scheme(self):
        self.assertFalse(is_valid_endpoint_url('foo.bar.com'))

    def test_no_new_lines(self):
        self.assertFalse(is_valid_endpoint_url('https://foo.bar.com\nbar/'))

    def test_long_hostname(self):
        long_hostname = 'htps://%s.com' % ('a' * 256)
        self.assertFalse(is_valid_endpoint_url(long_hostname))

    def test_hostname_can_end_with_dot(self):
        self.assertTrue(is_valid_endpoint_url('https://foo.bar.com./'))

    def test_hostname_no_dots(self):
        self.assertTrue(is_valid_endpoint_url('https://foo/'))


class TestFixS3Host(unittest.TestCase):
    def test_fix_s3_host_initial(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://s3-us-west-2.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name)
        self.assertEqual(request.url,
                         'https://bucket.s3.amazonaws.com/key.txt')
        self.assertEqual(request.auth_path, '/bucket/key.txt')

    def test_fix_s3_host_only_applied_once(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://s3-us-west-2.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name)
        # Calling the handler again should not affect the end result:
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name)
        self.assertEqual(request.url,
                         'https://bucket.s3.amazonaws.com/key.txt')
        # This was a bug previously.  We want to make sure that
        # calling fix_s3_host() again does not alter the auth_path.
        # Otherwise we'll get signature errors.
        self.assertEqual(request.auth_path, '/bucket/key.txt')

    def test_dns_style_not_used_for_get_bucket_location(self):
        original_url = 'https://s3-us-west-2.amazonaws.com/bucket?location'
        request = AWSRequest(
            method='GET', headers={},
            url=original_url,
        )
        signature_version = 's3'
        region_name = 'us-west-2'
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name)
        # The request url should not have been modified because this is
        # a request for GetBucketLocation.
        self.assertEqual(request.url, original_url)

    def test_can_provide_default_endpoint_url(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://s3-us-west-2.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name,
            default_endpoint_url='foo.s3.amazonaws.com')
        self.assertEqual(request.url,
                         'https://bucket.foo.s3.amazonaws.com/key.txt')

    def test_no_endpoint_url_uses_request_url(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://s3-us-west-2.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        fix_s3_host(
            request=request, signature_version=signature_version,
            region_name=region_name,
            # A value of None means use the url in the current request.
            default_endpoint_url=None,
        )
        self.assertEqual(request.url,
                         'https://bucket.s3-us-west-2.amazonaws.com/key.txt')


class TestSwitchToVirtualHostStyle(unittest.TestCase):
    def test_switch_to_virtual_host_style(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        self.assertEqual(request.url,
                         'https://bucket.foo.amazonaws.com/key.txt')
        self.assertEqual(request.auth_path, '/bucket/key.txt')

    def test_uses_default_endpoint(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name, default_endpoint_url='s3.amazonaws.com')
        self.assertEqual(request.url,
                         'https://bucket.s3.amazonaws.com/key.txt')
        self.assertEqual(request.auth_path, '/bucket/key.txt')

    def test_throws_invalid_dns_name_error(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/mybucket.foo/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        with self.assertRaises(InvalidDNSNameError):
            switch_to_virtual_host_style(
                request=request, signature_version=signature_version,
                region_name=region_name)

    def test_fix_s3_host_only_applied_once(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        # Calling the handler again should not affect the end result:
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        self.assertEqual(request.url,
                         'https://bucket.foo.amazonaws.com/key.txt')
        # This was a bug previously.  We want to make sure that
        # calling fix_s3_host() again does not alter the auth_path.
        # Otherwise we'll get signature errors.
        self.assertEqual(request.auth_path, '/bucket/key.txt')

    def test_virtual_host_style_for_make_bucket(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/bucket'
        )
        region_name = 'us-west-2'
        signature_version = 's3'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        self.assertEqual(request.url,
                         'https://bucket.foo.amazonaws.com/')

    def test_virtual_host_style_not_used_for_get_bucket_location(self):
        original_url = 'https://foo.amazonaws.com/bucket?location'
        request = AWSRequest(
            method='GET', headers={},
            url=original_url,
        )
        signature_version = 's3'
        region_name = 'us-west-2'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        # The request url should not have been modified because this is
        # a request for GetBucketLocation.
        self.assertEqual(request.url, original_url)

    def test_virtual_host_style_not_used_for_list_buckets(self):
        original_url = 'https://foo.amazonaws.com/'
        request = AWSRequest(
            method='GET', headers={},
            url=original_url,
        )
        signature_version = 's3'
        region_name = 'us-west-2'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name)
        # The request url should not have been modified because this is
        # a request for GetBucketLocation.
        self.assertEqual(request.url, original_url)

    def test_is_unaffected_by_sigv4(self):
        request = AWSRequest(
            method='PUT', headers={},
            url='https://foo.amazonaws.com/bucket/key.txt'
        )
        region_name = 'us-west-2'
        signature_version = 's3v4'
        switch_to_virtual_host_style(
            request=request, signature_version=signature_version,
            region_name=region_name, default_endpoint_url='s3.amazonaws.com')
        self.assertEqual(request.url,
                         'https://bucket.s3.amazonaws.com/key.txt')


class TestInstanceCache(unittest.TestCase):
    class DummyClass(object):
        def __init__(self, cache):
            self._instance_cache = cache

        @instance_cache
        def add(self, x, y):
            return x + y

        @instance_cache
        def sub(self, x, y):
            return x - y

    def setUp(self):
        self.cache = {}

    def test_cache_single_method_call(self):
        adder = self.DummyClass(self.cache)
        self.assertEqual(adder.add(2, 1), 3)
        # This should result in one entry in the cache.
        self.assertEqual(len(self.cache), 1)
        # When we call the method with the same args,
        # we should reuse the same entry in the cache.
        self.assertEqual(adder.add(2, 1), 3)
        self.assertEqual(len(self.cache), 1)

    def test_can_cache_multiple_methods(self):
        adder = self.DummyClass(self.cache)
        adder.add(2, 1)

        # A different method results in a new cache entry,
        # so now there should be two elements in the cache.
        self.assertEqual(adder.sub(2, 1), 1)
        self.assertEqual(len(self.cache), 2)
        self.assertEqual(adder.sub(2, 1), 1)

    def test_can_cache_kwargs(self):
        adder = self.DummyClass(self.cache)
        adder.add(x=2, y=1)
        self.assertEqual(adder.add(x=2, y=1), 3)
        self.assertEqual(len(self.cache), 1)


class TestMergeDicts(unittest.TestCase):
    def test_merge_dicts_overrides(self):
        first = {
            'foo': {'bar': {'baz': {'one': 'ORIGINAL', 'two': 'ORIGINAL'}}}}
        second = {'foo': {'bar': {'baz': {'one': 'UPDATE'}}}}

        merge_dicts(first, second)
        # The value from the second dict wins.
        self.assertEqual(first['foo']['bar']['baz']['one'], 'UPDATE')
        # And we still preserve the other attributes.
        self.assertEqual(first['foo']['bar']['baz']['two'], 'ORIGINAL')

    def test_merge_dicts_new_keys(self):
        first = {
            'foo': {'bar': {'baz': {'one': 'ORIGINAL', 'two': 'ORIGINAL'}}}}
        second = {'foo': {'bar': {'baz': {'three': 'UPDATE'}}}}

        merge_dicts(first, second)
        self.assertEqual(first['foo']['bar']['baz']['one'], 'ORIGINAL')
        self.assertEqual(first['foo']['bar']['baz']['two'], 'ORIGINAL')
        self.assertEqual(first['foo']['bar']['baz']['three'], 'UPDATE')

    def test_merge_empty_dict_does_nothing(self):
        first = {'foo': {'bar': 'baz'}}
        merge_dicts(first, {})
        self.assertEqual(first, {'foo': {'bar': 'baz'}})

    def test_more_than_one_sub_dict(self):
        first = {'one': {'inner': 'ORIGINAL', 'inner2': 'ORIGINAL'},
                 'two': {'inner': 'ORIGINAL', 'inner2': 'ORIGINAL'}}
        second = {'one': {'inner': 'UPDATE'}, 'two': {'inner': 'UPDATE'}}

        merge_dicts(first, second)
        self.assertEqual(first['one']['inner'], 'UPDATE')
        self.assertEqual(first['one']['inner2'], 'ORIGINAL')

        self.assertEqual(first['two']['inner'], 'UPDATE')
        self.assertEqual(first['two']['inner2'], 'ORIGINAL')

    def test_new_keys(self):
        first = {'one': {'inner': 'ORIGINAL'}, 'two': {'inner': 'ORIGINAL'}}
        second = {'three': {'foo': {'bar': 'baz'}}}
        # In this case, second has no keys in common, but we'd still expect
        # this to get merged.
        merge_dicts(first, second)
        self.assertEqual(first['three']['foo']['bar'], 'baz')

    def test_list_values_no_append(self):
        dict1 = {'Foo': ['old_foo_value']}
        dict2 = {'Foo': ['new_foo_value']}
        merge_dicts(dict1, dict2)
        self.assertEqual(
            dict1, {'Foo': ['new_foo_value']})

    def test_list_values_append(self):
        dict1 = {'Foo': ['old_foo_value']}
        dict2 = {'Foo': ['new_foo_value']}
        merge_dicts(dict1, dict2, append_lists=True)
        self.assertEqual(
            dict1, {'Foo': ['old_foo_value', 'new_foo_value']})

    def test_list_values_mismatching_types(self):
        dict1 = {'Foo': 'old_foo_value'}
        dict2 = {'Foo': ['new_foo_value']}
        merge_dicts(dict1, dict2, append_lists=True)
        self.assertEqual(
            dict1, {'Foo': ['new_foo_value']})

    def test_list_values_missing_key(self):
        dict1 = {}
        dict2 = {'Foo': ['foo_value']}
        merge_dicts(dict1, dict2, append_lists=True)
        self.assertEqual(
            dict1, {'Foo': ['foo_value']})


class TestGetServiceModuleName(unittest.TestCase):
    def setUp(self):
        self.service_description = {
            'metadata': {
                'serviceFullName': 'AWS MyService',
                'apiVersion': '2014-01-01',
                'endpointPrefix': 'myservice',
                'signatureVersion': 'v4',
                'protocol': 'query'
            },
            'operations': {},
            'shapes': {},
        }
        self.service_model = ServiceModel(
            self.service_description, 'myservice')

    def test_default(self):
        self.assertEqual(
            get_service_module_name(self.service_model),
            'MyService'
        )

    def test_client_name_with_amazon(self):
        self.service_description['metadata']['serviceFullName'] = (
            'Amazon MyService')
        self.assertEqual(
            get_service_module_name(self.service_model),
            'MyService'
        )

    def test_client_name_using_abreviation(self):
        self.service_description['metadata']['serviceAbbreviation'] = (
            'Abbreviation')
        self.assertEqual(
            get_service_module_name(self.service_model),
            'Abbreviation'
        )

    def test_client_name_with_non_alphabet_characters(self):
        self.service_description['metadata']['serviceFullName'] = (
            'Amazon My-Service')
        self.assertEqual(
            get_service_module_name(self.service_model),
            'MyService'
        )

    def test_client_name_with_no_full_name_or_abbreviation(self):
        del self.service_description['metadata']['serviceFullName']
        self.assertEqual(
            get_service_module_name(self.service_model),
            'myservice'
        )


class TestPercentEncodeSequence(unittest.TestCase):
    def test_percent_encode_empty(self):
        self.assertEqual(percent_encode_sequence({}), '')

    def test_percent_encode_special_chars(self):
        self.assertEqual(
            percent_encode_sequence({'k1': 'with spaces++/'}),
            'k1=with%20spaces%2B%2B%2F')

    def test_percent_encode_string_string_tuples(self):
        self.assertEqual(percent_encode_sequence([('k1', 'v1'), ('k2', 'v2')]),
                         'k1=v1&k2=v2')

    def test_percent_encode_dict_single_pair(self):
        self.assertEqual(percent_encode_sequence({'k1': 'v1'}), 'k1=v1')

    def test_percent_encode_dict_string_string(self):
        self.assertEqual(
            percent_encode_sequence(OrderedDict([('k1', 'v1'), ('k2', 'v2')])),
                                    'k1=v1&k2=v2')

    def test_percent_encode_single_list_of_values(self):
        self.assertEqual(percent_encode_sequence({'k1': ['a', 'b', 'c']}),
                         'k1=a&k1=b&k1=c')

    def test_percent_encode_list_values_of_string(self):
        self.assertEqual(
            percent_encode_sequence(
                OrderedDict([('k1', ['a', 'list']),
                             ('k2', ['another', 'list'])])),
            'k1=a&k1=list&k2=another&k2=list')


class TestSwitchHostS3Accelerate(unittest.TestCase):
    def setUp(self):
        self.original_url = 'https://s3.amazonaws.com/foo/key.txt'
        self.request = AWSRequest(
            method='PUT', headers={},
            url=self.original_url
        )
        self.client_config = Config()
        self.request.context['client_config'] = self.client_config

    def test_switch_host(self):
        switch_host_s3_accelerate(self.request, 'PutObject')
        self.assertEqual(
            self.request.url,
            'https://s3-accelerate.amazonaws.com/foo/key.txt')

    def test_do_not_switch_black_listed_operations(self):
        # It should not get switched for ListBuckets, DeleteBucket, and
        # CreateBucket
        blacklist_ops = [
            'ListBuckets',
            'DeleteBucket',
            'CreateBucket'
        ]
        for op_name in blacklist_ops:
            switch_host_s3_accelerate(self.request, op_name)
            self.assertEqual(self.request.url, self.original_url)

    def test_uses_original_endpoint_scheme(self):
        self.request.url = 'http://s3.amazonaws.com/foo/key.txt'
        switch_host_s3_accelerate(self.request, 'PutObject')
        self.assertEqual(
            self.request.url,
            'http://s3-accelerate.amazonaws.com/foo/key.txt')

    def test_uses_dualstack(self):
        self.client_config.s3 = {'use_dualstack_endpoint': True}
        self.original_url = 'https://s3.dualstack.amazonaws.com/foo/key.txt'
        self.request = AWSRequest(
            method='PUT', headers={},
            url=self.original_url
        )
        self.request.context['client_config'] = self.client_config
        switch_host_s3_accelerate(self.request, 'PutObject')
        self.assertEqual(
            self.request.url,
            'https://s3-accelerate.dualstack.amazonaws.com/foo/key.txt')


class TestDeepMerge(unittest.TestCase):
    def test_simple_merge(self):
        a = {'key': 'value'}
        b = {'otherkey': 'othervalue'}
        deep_merge(a, b)

        expected = {'key': 'value', 'otherkey': 'othervalue'}
        self.assertEqual(a, expected)

    def test_merge_list(self):
        # Lists are treated as opaque data and so no effort should be made to
        # combine them.
        a = {'key': ['original']}
        b = {'key': ['new']}
        deep_merge(a, b)
        self.assertEqual(a, {'key': ['new']})

    def test_merge_number(self):
        # The value from b is always taken
        a = {'key': 10}
        b = {'key': 45}
        deep_merge(a, b)
        self.assertEqual(a, {'key': 45})

        a = {'key': 45}
        b = {'key': 10}
        deep_merge(a, b)
        self.assertEqual(a, {'key': 10})

    def test_merge_boolean(self):
        # The value from b is always taken
        a = {'key': False}
        b = {'key': True}
        deep_merge(a, b)
        self.assertEqual(a, {'key': True})

        a = {'key': True}
        b = {'key': False}
        deep_merge(a, b)
        self.assertEqual(a, {'key': False})

    def test_merge_string(self):
        a = {'key': 'value'}
        b = {'key': 'othervalue'}
        deep_merge(a, b)
        self.assertEqual(a, {'key': 'othervalue'})

    def test_merge_overrides_value(self):
        # The value from b is always taken, even when it's a different type
        a = {'key': 'original'}
        b = {'key': {'newkey': 'newvalue'}}
        deep_merge(a, b)
        self.assertEqual(a, {'key': {'newkey': 'newvalue'}})

        a = {'key': {'anotherkey': 'value'}}
        b = {'key': 'newvalue'}
        deep_merge(a, b)
        self.assertEqual(a, {'key': 'newvalue'})

    def test_deep_merge(self):
        a = {
            'first': {
                'second': {
                    'key': 'value',
                    'otherkey': 'othervalue'
                },
                'key': 'value'
            }
        }
        b = {
            'first': {
                'second': {
                    'otherkey': 'newvalue',
                    'yetanotherkey': 'yetanothervalue'
                }
            }
        }
        deep_merge(a, b)

        expected = {
            'first': {
                'second': {
                    'key': 'value',
                    'otherkey': 'newvalue',
                    'yetanotherkey': 'yetanothervalue'
                },
                'key': 'value'
            }
        }
        self.assertEqual(a, expected)


class TestS3RegionRedirector(unittest.TestCase):
    def setUp(self):
        self.endpoint_bridge = mock.Mock()
        self.endpoint_bridge.resolve.return_value = {
            'endpoint_url': 'https://eu-central-1.amazonaws.com'
        }
        self.client = mock.Mock()
        self.cache = {}
        self.redirector = S3RegionRedirector(self.endpoint_bridge, self.client)
        self.set_client_response_headers({})
        self.operation = mock.Mock()
        self.operation.name = 'foo'

    def set_client_response_headers(self, headers):
        error_response = ClientError({
            'Error': {
                'Code': '',
                'Message': ''
            },
            'ResponseMetadata': {
                'HTTPHeaders': headers
            }
        }, 'HeadBucket')
        success_response = {
            'ResponseMetadata': {
                'HTTPHeaders': headers
            }
        }
        self.client.head_bucket.side_effect = [
            error_response, success_response]

    def test_set_request_url(self):
        params = {'url': 'https://us-west-2.amazonaws.com/foo'}
        context = {'signing': {
            'endpoint': 'https://eu-central-1.amazonaws.com'
        }}
        self.redirector.set_request_url(params, context)
        self.assertEqual(
            params['url'], 'https://eu-central-1.amazonaws.com/foo')

    def test_only_changes_request_url_if_endpoint_present(self):
        params = {'url': 'https://us-west-2.amazonaws.com/foo'}
        context = {}
        self.redirector.set_request_url(params, context)
        self.assertEqual(
            params['url'], 'https://us-west-2.amazonaws.com/foo')

    def test_set_request_url_keeps_old_scheme(self):
        params = {'url': 'http://us-west-2.amazonaws.com/foo'}
        context = {'signing': {
            'endpoint': 'https://eu-central-1.amazonaws.com'
        }}
        self.redirector.set_request_url(params, context)
        self.assertEqual(
            params['url'], 'http://eu-central-1.amazonaws.com/foo')

    def test_sets_signing_context_from_cache(self):
        signing_context = {'endpoint': 'bar'}
        self.cache['foo'] = signing_context
        self.redirector = S3RegionRedirector(
            self.endpoint_bridge, self.client, cache=self.cache)
        params = {'Bucket': 'foo'}
        context = {}
        self.redirector.redirect_from_cache(params, context)
        self.assertEqual(context.get('signing'), signing_context)

    def test_only_changes_context_if_bucket_in_cache(self):
        signing_context = {'endpoint': 'bar'}
        self.cache['bar'] = signing_context
        self.redirector = S3RegionRedirector(
            self.endpoint_bridge, self.client, cache=self.cache)
        params = {'Bucket': 'foo'}
        context = {}
        self.redirector.redirect_from_cache(params, context)
        self.assertNotEqual(context.get('signing'), signing_context)

    def test_redirect_from_error(self):
        request_dict = {
            'context': {'signing': {'bucket': 'foo'}},
            'url': 'https://us-west-2.amazonaws.com/foo'
        }
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo'
            },
            'ResponseMetadata': {
                'HTTPHeaders': {'x-amz-bucket-region': 'eu-central-1'}
            }
        })

        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)

        # The response needs to be 0 so that there is no retry delay
        self.assertEqual(redirect_response, 0)

        self.assertEqual(
            request_dict['url'], 'https://eu-central-1.amazonaws.com/foo')

        expected_signing_context = {
            'endpoint': 'https://eu-central-1.amazonaws.com',
            'bucket': 'foo',
            'region': 'eu-central-1'
        }
        signing_context = request_dict['context'].get('signing')
        self.assertEqual(signing_context, expected_signing_context)

    def test_does_not_redirect_unless_permanentredirect_recieved(self):
        request_dict = {}
        response = (None, {})
        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)
        self.assertIsNone(redirect_response)
        self.assertEqual(request_dict, {})

    def test_does_not_redirect_if_region_cannot_be_found(self):
        request_dict = {'url': 'https://us-west-2.amazonaws.com/foo',
                        'context': {'signing': {'bucket': 'foo'}}}
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo'
            },
            'ResponseMetadata': {
                'HTTPHeaders': {}
            }
        })

        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)

        self.assertIsNone(redirect_response)

    def test_redirects_301(self):
        request_dict = {'url': 'https://us-west-2.amazonaws.com/foo',
                        'context': {'signing': {'bucket': 'foo'}}}
        response = (None, {
            'Error': {
                'Code': '301',
                'Message': 'Moved Permanently'
            },
            'ResponseMetadata': {
                'HTTPHeaders': {'x-amz-bucket-region': 'eu-central-1'}
            }
        })

        self.operation.name = 'HeadObject'
        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)
        self.assertEqual(redirect_response, 0)

        self.operation.name = 'ListObjects'
        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)
        self.assertIsNone(redirect_response)

    def test_does_not_redirect_if_None_response(self):
        request_dict = {'url': 'https://us-west-2.amazonaws.com/foo',
                        'context': {'signing': {'bucket': 'foo'}}}
        response = None
        redirect_response = self.redirector.redirect_from_error(
            request_dict, response, self.operation)
        self.assertIsNone(redirect_response)

    def test_get_region_from_response(self):
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo'
            },
            'ResponseMetadata': {
                'HTTPHeaders': {'x-amz-bucket-region': 'eu-central-1'}
            }
        })
        region = self.redirector.get_bucket_region('foo', response)
        self.assertEqual(region, 'eu-central-1')

    def test_get_region_from_response_error_body(self):
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo',
                'Region': 'eu-central-1'
            },
            'ResponseMetadata': {
                'HTTPHeaders': {}
            }
        })
        region = self.redirector.get_bucket_region('foo', response)
        self.assertEqual(region, 'eu-central-1')

    def test_get_region_from_head_bucket_error(self):
        self.set_client_response_headers(
            {'x-amz-bucket-region': 'eu-central-1'})
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo',
            },
            'ResponseMetadata': {
                'HTTPHeaders': {}
            }
        })
        region = self.redirector.get_bucket_region('foo', response)
        self.assertEqual(region, 'eu-central-1')

    def test_get_region_from_head_bucket_success(self):
        success_response = {
            'ResponseMetadata': {
                'HTTPHeaders': {'x-amz-bucket-region': 'eu-central-1'}
            }
        }
        self.client.head_bucket.side_effect = None
        self.client.head_bucket.return_value = success_response
        response = (None, {
            'Error': {
                'Code': 'PermanentRedirect',
                'Endpoint': 'foo.eu-central-1.amazonaws.com',
                'Bucket': 'foo',
            },
            'ResponseMetadata': {
                'HTTPHeaders': {}
            }
        })
        region = self.redirector.get_bucket_region('foo', response)
        self.assertEqual(region, 'eu-central-1')


class TestContainerMetadataFetcher(unittest.TestCase):
    def setUp(self):
        self.responses = []
        self.http = mock.Mock()
        self.sleep = mock.Mock()

    def create_fetcher(self):
        return ContainerMetadataFetcher(self.http, sleep=self.sleep)

    def fake_response(self, status_code, body):
        response = mock.Mock()
        response.status_code = status_code
        response.text = body
        return response

    def set_http_responses_to(self, *responses):
        http_responses = []
        for response in responses:
            if isinstance(response, Exception):
                # Simulating an error condition.
                http_response = response
            elif hasattr(response, 'status_code'):
                # It's a precreated fake_response.
                http_response = response
            else:
                http_response = self.fake_response(
                    status_code=200, body=json.dumps(response))
            http_responses.append(http_response)
        self.http.get.side_effect = http_responses

    def test_can_retrieve_uri(self):
        json_body =  {
            "AccessKeyId" : "a",
            "SecretAccessKey" : "b",
            "Token" : "c",
            "Expiration" : "d"
        }
        self.set_http_responses_to(json_body)

        fetcher = self.create_fetcher()
        response = fetcher.retrieve_uri('/foo?id=1')

        self.assertEqual(response, json_body)
        # Ensure we made calls to the right endpoint.
        self.http.get.assert_called_with(
            'http://169.254.170.2/foo?id=1',
            headers={'Accept': 'application/json'},
            timeout=fetcher.TIMEOUT_SECONDS,
        )

    def test_can_retry_requests(self):
        success_response = {
            "AccessKeyId" : "a",
            "SecretAccessKey" : "b",
            "Token" : "c",
            "Expiration" : "d"
        }
        self.set_http_responses_to(
            # First response is a connection error, should
            # be retried.
            requests.ConnectionError(),
            # Second response is the successful JSON response
            # with credentials.
            success_response,
        )
        fetcher = self.create_fetcher()
        response = fetcher.retrieve_uri('/foo?id=1')
        self.assertEqual(response, success_response)

    def test_propagates_credential_error_on_http_errors(self):
        self.set_http_responses_to(
            # In this scenario, we never get a successful response.
            requests.ConnectionError(),
            requests.ConnectionError(),
            requests.ConnectionError(),
            requests.ConnectionError(),
            requests.ConnectionError(),
        )
        # As a result, we expect an appropriate error to be raised.
        fetcher = self.create_fetcher()
        with self.assertRaises(MetadataRetrievalError):
            fetcher.retrieve_uri('/foo?id=1')
        self.assertEqual(self.http.get.call_count, fetcher.RETRY_ATTEMPTS)

    def test_error_raised_on_non_200_response(self):
        self.set_http_responses_to(
            self.fake_response(status_code=404, body='Error not found'),
            self.fake_response(status_code=404, body='Error not found'),
            self.fake_response(status_code=404, body='Error not found'),
        )
        fetcher = self.create_fetcher()
        with self.assertRaises(MetadataRetrievalError):
            fetcher.retrieve_uri('/foo?id=1')
        # Should have tried up to RETRY_ATTEMPTS.
        self.assertEqual(self.http.get.call_count, fetcher.RETRY_ATTEMPTS)

    def test_error_raised_on_no_json_response(self):
        # If the service returns a sucess response but with a body that
        # does not contain JSON, we should still retry up to RETRY_ATTEMPTS,
        # but after exhausting retries we propagate the exception.
        self.set_http_responses_to(
            self.fake_response(status_code=200, body='Not JSON'),
            self.fake_response(status_code=200, body='Not JSON'),
            self.fake_response(status_code=200, body='Not JSON'),
        )
        fetcher = self.create_fetcher()
        with self.assertRaises(MetadataRetrievalError):
            fetcher.retrieve_uri('/foo?id=1')
        # Should have tried up to RETRY_ATTEMPTS.
        self.assertEqual(self.http.get.call_count, fetcher.RETRY_ATTEMPTS)


if __name__ == '__main__':
    unittest.main()