# Copyright (C) 2013 Canonical Ltd.

# Copyright 2019 Joyent, Inc.

#

# Author: Ben Howard <ben.howard@canonical.com>

#

# This file is part of cloud-init. See LICENSE file for license information.

'''This is a testcase for the SmartOS datasource.

It replicates a serial console and acts like the SmartOS console does in

order to validate return responses.

'''

from binascii import crc32

import json

import multiprocessing

import os

import os.path

import re

import signal

import stat

import unittest

import uuid

from cloudinit import serial

from cloudinit.sources import DataSourceSmartOS

from cloudinit.sources.DataSourceSmartOS import (

    convert_smartos_network_data as convert_net,

    SMARTOS_ENV_KVM, SERIAL_DEVICE, get_smartos_environ,

    identify_file)

from cloudinit.event import EventType

from cloudinit import helpers as c_helpers

from cloudinit.util import (b64e, write_file)

from cloudinit.subp import (subp, ProcessExecutionError, which)

from cloudinit.tests.helpers import (

    CiTestCase, mock, FilesystemMockingTestCase, skipIf)

try:

    import serial as _pyserial

    assert _pyserial  # avoid pyflakes error F401: import unused

    HAS_PYSERIAL = True

except ImportError:

    HAS_PYSERIAL = False

DSMOS = 'cloudinit.sources.DataSourceSmartOS'

SDC_NICS = json.loads("""

[

    {

        "nic_tag": "external",

        "primary": true,

        "mtu": 1500,

        "model": "virtio",

        "gateway": "8.12.42.1",

        "netmask": "255.255.255.0",

        "ip": "8.12.42.102",

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "gateways": [

            "8.12.42.1"

        ],

        "vlan_id": 324,

        "mac": "90:b8:d0:f5:e4:f5",

        "interface": "net0",

        "ips": [

            "8.12.42.102/24"

        ]

    },

    {

        "nic_tag": "sdc_overlay/16187209",

        "gateway": "192.168.128.1",

        "model": "virtio",

        "mac": "90:b8:d0:a5:ff:cd",

        "netmask": "255.255.252.0",

        "ip": "192.168.128.93",

        "network_uuid": "4cad71da-09bc-452b-986d-03562a03a0a9",

        "gateways": [

            "192.168.128.1"

        ],

        "vlan_id": 2,

        "mtu": 8500,

        "interface": "net1",

        "ips": [

            "192.168.128.93/22"

        ]

    }

]

""")

SDC_NICS_ALT = json.loads("""

[

    {

        "interface": "net0",

        "mac": "90:b8:d0:ae:64:51",

        "vlan_id": 324,

        "nic_tag": "external",

        "gateway": "8.12.42.1",

        "gateways": [

          "8.12.42.1"

        ],

        "netmask": "255.255.255.0",

        "ip": "8.12.42.51",

        "ips": [

          "8.12.42.51/24"

        ],

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "model": "virtio",

        "mtu": 1500,

        "primary": true

    },

    {

        "interface": "net1",

        "mac": "90:b8:d0:bd:4f:9c",

        "vlan_id": 600,

        "nic_tag": "internal",

        "netmask": "255.255.255.0",

        "ip": "10.210.1.217",

        "ips": [

          "10.210.1.217/24"

        ],

        "network_uuid": "98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

        "model": "virtio",

        "mtu": 1500

    }

]

""")

SDC_NICS_DHCP = json.loads("""

[

    {

        "interface": "net0",

        "mac": "90:b8:d0:ae:64:51",

        "vlan_id": 324,

        "nic_tag": "external",

        "gateway": "8.12.42.1",

        "gateways": [

          "8.12.42.1"

        ],

        "netmask": "255.255.255.0",

        "ip": "8.12.42.51",

        "ips": [

          "8.12.42.51/24"

        ],

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "model": "virtio",

        "mtu": 1500,

        "primary": true

    },

    {

        "interface": "net1",

        "mac": "90:b8:d0:bd:4f:9c",

        "vlan_id": 600,

        "nic_tag": "internal",

        "netmask": "255.255.255.0",

        "ip": "10.210.1.217",

        "ips": [

          "dhcp"

        ],

        "network_uuid": "98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

        "model": "virtio",

        "mtu": 1500

    }

]

""")

SDC_NICS_MIP = json.loads("""

[

    {

        "interface": "net0",

        "mac": "90:b8:d0:ae:64:51",

        "vlan_id": 324,

        "nic_tag": "external",

        "gateway": "8.12.42.1",

        "gateways": [

          "8.12.42.1"

        ],

        "netmask": "255.255.255.0",

        "ip": "8.12.42.51",

        "ips": [

          "8.12.42.51/24",

          "8.12.42.52/24"

        ],

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "model": "virtio",

        "mtu": 1500,

        "primary": true

    },

    {

        "interface": "net1",

        "mac": "90:b8:d0:bd:4f:9c",

        "vlan_id": 600,

        "nic_tag": "internal",

        "netmask": "255.255.255.0",

        "ip": "10.210.1.217",

        "ips": [

          "10.210.1.217/24",

          "10.210.1.151/24"

        ],

        "network_uuid": "98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

        "model": "virtio",

        "mtu": 1500

    }

]

""")

SDC_NICS_MIP_IPV6 = json.loads("""

[

    {

        "interface": "net0",

        "mac": "90:b8:d0:ae:64:51",

        "vlan_id": 324,

        "nic_tag": "external",

        "gateway": "8.12.42.1",

        "gateways": [

          "8.12.42.1"

        ],

        "netmask": "255.255.255.0",

        "ip": "8.12.42.51",

        "ips": [

          "2001:4800:78ff:1b:be76:4eff:fe06:96b3/64",

          "8.12.42.51/24"

        ],

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "model": "virtio",

        "mtu": 1500,

        "primary": true

    },

    {

        "interface": "net1",

        "mac": "90:b8:d0:bd:4f:9c",

        "vlan_id": 600,

        "nic_tag": "internal",

        "netmask": "255.255.255.0",

        "ip": "10.210.1.217",

        "ips": [

          "10.210.1.217/24"

        ],

        "network_uuid": "98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

        "model": "virtio",

        "mtu": 1500

    }

]

""")

SDC_NICS_IPV4_IPV6 = json.loads("""

[

    {

        "interface": "net0",

        "mac": "90:b8:d0:ae:64:51",

        "vlan_id": 324,

        "nic_tag": "external",

        "gateway": "8.12.42.1",

        "gateways": ["8.12.42.1", "2001::1", "2001::2"],

        "netmask": "255.255.255.0",

        "ip": "8.12.42.51",

        "ips": ["2001::10/64", "8.12.42.51/24", "2001::11/64",

                "8.12.42.52/32"],

        "network_uuid": "992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

        "model": "virtio",

        "mtu": 1500,

        "primary": true

    },

    {

        "interface": "net1",

        "mac": "90:b8:d0:bd:4f:9c",

        "vlan_id": 600,

        "nic_tag": "internal",

        "netmask": "255.255.255.0",

        "ip": "10.210.1.217",

        "ips": ["10.210.1.217/24"],

        "gateways": ["10.210.1.210"],

        "network_uuid": "98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

        "model": "virtio",

        "mtu": 1500

    }

]

""")

SDC_NICS_SINGLE_GATEWAY = json.loads("""

[

  {

    "interface":"net0",

    "mac":"90:b8:d0:d8:82:b4",

    "vlan_id":324,

    "nic_tag":"external",

    "gateway":"8.12.42.1",

    "gateways":["8.12.42.1"],

    "netmask":"255.255.255.0",

    "ip":"8.12.42.26",

    "ips":["8.12.42.26/24"],

    "network_uuid":"992fc7ce-6aac-4b74-aed6-7b9d2c6c0bfe",

    "model":"virtio",

    "mtu":1500,

    "primary":true

  },

  {

    "interface":"net1",

    "mac":"90:b8:d0:0a:51:31",

    "vlan_id":600,

    "nic_tag":"internal",

    "netmask":"255.255.255.0",

    "ip":"10.210.1.27",

    "ips":["10.210.1.27/24"],

    "network_uuid":"98657fdf-11f4-4ee2-88a4-ce7fe73e33a6",

    "model":"virtio",

    "mtu":1500

  }

]

""")

MOCK_RETURNS = {

    'hostname': 'test-host',

    'root_authorized_keys': 'ssh-rsa AAAAB3Nz...aC1yc2E= keyname',

    'disable_iptables_flag': None,

    'enable_motd_sys_info': None,

    'test-var1': 'some data',

    'cloud-init:user-data': '\n'.join(['#!/bin/sh', '/bin/true', '']),

    'sdc:datacenter_name': 'somewhere2',

    'sdc:operator-script': '\n'.join(['bin/true', '']),

    'sdc:uuid': str(uuid.uuid4()),

    'sdc:vendor-data': '\n'.join(['VENDOR_DATA', '']),

    'user-data': '\n'.join(['something', '']),

    'user-script': '\n'.join(['/bin/true', '']),

    'sdc:nics': json.dumps(SDC_NICS),

}

DMI_DATA_RETURN = 'smartdc'

# Useful for calculating the length of a frame body.  A SUCCESS body will be

# followed by more characters or be one character less if SUCCESS with no

# payload.  See Section 4.3 of https://eng.joyent.com/mdata/protocol.html.

SUCCESS_LEN = len('0123abcd SUCCESS ')

NOTFOUND_LEN = len('0123abcd NOTFOUND')

class PsuedoJoyentClient(object):

    def __init__(self, data=None):

        if data is None:

            data = MOCK_RETURNS.copy()

        self.data = data

        self._is_open = False

        return

    def get(self, key, default=None, strip=False):

        if key in self.data:

            r = self.data[key]

            if strip:

                r = r.strip()

        else:

            r = default

        return r

    def get_json(self, key, default=None):

        result = self.get(key, default=default)

        if result is None:

            return default

        return json.loads(result)

    def exists(self):

        return True

    def open_transport(self):

        assert(not self._is_open)

        self._is_open = True

    def close_transport(self):

        assert(self._is_open)

        self._is_open = False

class TestSmartOSDataSource(FilesystemMockingTestCase):

    jmc_cfact = None

    get_smartos_environ = None

    def setUp(self):

        super(TestSmartOSDataSource, self).setUp()

        self.add_patch(DSMOS + ".get_smartos_environ", "get_smartos_environ")

        self.add_patch(DSMOS + ".jmc_client_factory", "jmc_cfact")

        self.legacy_user_d = self.tmp_path('legacy_user_tmp')

        os.mkdir(self.legacy_user_d)

        self.add_patch(DSMOS + ".LEGACY_USER_D", "m_legacy_user_d",

                       autospec=False, new=self.legacy_user_d)

        self.add_patch(DSMOS + ".identify_file", "m_identify_file",

                       return_value="text/plain")

    def _get_ds(self, mockdata=None, mode=DataSourceSmartOS.SMARTOS_ENV_KVM,

                sys_cfg=None, ds_cfg=None):

        self.jmc_cfact.return_value = PsuedoJoyentClient(mockdata)

        self.get_smartos_environ.return_value = mode

        tmpd = self.tmp_dir()

        dirs = {'cloud_dir': self.tmp_path('cloud_dir', tmpd),

                'run_dir': self.tmp_path('run_dir')}

        for d in dirs.values():

            os.mkdir(d)

        paths = c_helpers.Paths(dirs)

        if sys_cfg is None:

            sys_cfg = {}

        if ds_cfg is not None:

            sys_cfg['datasource'] = sys_cfg.get('datasource', {})

            sys_cfg['datasource']['SmartOS'] = ds_cfg

        return DataSourceSmartOS.DataSourceSmartOS(

            sys_cfg, distro=None, paths=paths)

    def test_no_base64(self):

        ds_cfg = {'no_base64_decode': ['test_var1'], 'all_base': True}

        dsrc = self._get_ds(ds_cfg=ds_cfg)

        ret = dsrc.get_data()

        self.assertTrue(ret)

    def test_uuid(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['sdc:uuid'],

                         dsrc.metadata['instance-id'])

    def test_platform_info(self):

        """All platform-related attributes are properly set."""

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        self.assertEqual('joyent', dsrc.cloud_name)

        self.assertEqual('joyent', dsrc.platform_type)

        self.assertEqual('serial (/dev/ttyS1)', dsrc.subplatform)

    def test_root_keys(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['root_authorized_keys'],

                         dsrc.metadata['public-keys'])

    def test_hostname_b64(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['hostname'],

                         dsrc.metadata['local-hostname'])

    def test_hostname(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['hostname'],

                         dsrc.metadata['local-hostname'])

    def test_hostname_if_no_sdc_hostname(self):

        my_returns = MOCK_RETURNS.copy()

        my_returns['sdc:hostname'] = 'sdc-' + my_returns['hostname']

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(my_returns['hostname'],

                         dsrc.metadata['local-hostname'])

    def test_sdc_hostname_if_no_hostname(self):

        my_returns = MOCK_RETURNS.copy()

        my_returns['sdc:hostname'] = 'sdc-' + my_returns['hostname']

        del my_returns['hostname']

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(my_returns['sdc:hostname'],

                         dsrc.metadata['local-hostname'])

    def test_sdc_uuid_if_no_hostname_or_sdc_hostname(self):

        my_returns = MOCK_RETURNS.copy()

        del my_returns['hostname']

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(my_returns['sdc:uuid'],

                         dsrc.metadata['local-hostname'])

    def test_userdata(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['user-data'],

                         dsrc.metadata['legacy-user-data'])

        self.assertEqual(MOCK_RETURNS['cloud-init:user-data'],

                         dsrc.userdata_raw)

    def test_sdc_nics(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(json.loads(MOCK_RETURNS['sdc:nics']),

                         dsrc.metadata['network-data'])

    def test_sdc_scripts(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['user-script'],

                         dsrc.metadata['user-script'])

        legacy_script_f = "%s/user-script" % self.legacy_user_d

        print("legacy_script_f=%s" % legacy_script_f)

        self.assertTrue(os.path.exists(legacy_script_f))

        self.assertTrue(os.path.islink(legacy_script_f))

        user_script_perm = oct(os.stat(legacy_script_f)[stat.ST_MODE])[-3:]

        self.assertEqual(user_script_perm, '700')

    def test_scripts_shebanged(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['user-script'],

                         dsrc.metadata['user-script'])

        legacy_script_f = "%s/user-script" % self.legacy_user_d

        self.assertTrue(os.path.exists(legacy_script_f))

        self.assertTrue(os.path.islink(legacy_script_f))

        shebang = None

        with open(legacy_script_f, 'r') as f:

            shebang = f.readlines()[0].strip()

        self.assertEqual(shebang, "#!/bin/bash")

        user_script_perm = oct(os.stat(legacy_script_f)[stat.ST_MODE])[-3:]

        self.assertEqual(user_script_perm, '700')

    def test_scripts_shebang_not_added(self):

        """

            Test that the SmartOS requirement that plain text scripts

            are executable. This test makes sure that plain texts scripts

            with out file magic have it added appropriately by cloud-init.

        """

        my_returns = MOCK_RETURNS.copy()

        my_returns['user-script'] = '\n'.join(['#!/usr/bin/perl',

                                               'print("hi")', ''])

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(my_returns['user-script'],

                         dsrc.metadata['user-script'])

        legacy_script_f = "%s/user-script" % self.legacy_user_d

        self.assertTrue(os.path.exists(legacy_script_f))

        self.assertTrue(os.path.islink(legacy_script_f))

        shebang = None

        with open(legacy_script_f, 'r') as f:

            shebang = f.readlines()[0].strip()

        self.assertEqual(shebang, "#!/usr/bin/perl")

    def test_userdata_removed(self):

        """

            User-data in the SmartOS world is supposed to be written to a file

            each and every boot. This tests to make sure that in the event the

            legacy user-data is removed, the existing user-data is backed-up

            and there is no /var/db/user-data left.

        """

        user_data_f = "%s/mdata-user-data" % self.legacy_user_d

        with open(user_data_f, 'w') as f:

            f.write("PREVIOUS")

        my_returns = MOCK_RETURNS.copy()

        del my_returns['user-data']

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertFalse(dsrc.metadata.get('legacy-user-data'))

        found_new = False

        for root, _dirs, files in os.walk(self.legacy_user_d):

            for name in files:

                name_f = os.path.join(root, name)

                permissions = oct(os.stat(name_f)[stat.ST_MODE])[-3:]

                if re.match(r'.*\/mdata-user-data$', name_f):

                    found_new = True

                    print(name_f)

                    self.assertEqual(permissions, '400')

        self.assertFalse(found_new)

    def test_vendor_data_not_default(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['sdc:vendor-data'],

                         dsrc.metadata['vendor-data'])

    def test_default_vendor_data(self):

        my_returns = MOCK_RETURNS.copy()

        def_op_script = my_returns['sdc:vendor-data']

        del my_returns['sdc:vendor-data']

        dsrc = self._get_ds(mockdata=my_returns)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertNotEqual(def_op_script, dsrc.metadata['vendor-data'])

        # we expect default vendor-data is a boothook

        self.assertTrue(dsrc.vendordata_raw.startswith("#cloud-boothook"))

    def test_disable_iptables_flag(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['disable_iptables_flag'],

                         dsrc.metadata['iptables_disable'])

    def test_motd_sys_info(self):

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(MOCK_RETURNS['enable_motd_sys_info'],

                         dsrc.metadata['motd_sys_info'])

    def test_default_ephemeral(self):

        # Test to make sure that the builtin config has the ephemeral

        # configuration.

        dsrc = self._get_ds()

        cfg = dsrc.get_config_obj()

        ret = dsrc.get_data()

        self.assertTrue(ret)

        assert 'disk_setup' in cfg

        assert 'fs_setup' in cfg

        self.assertIsInstance(cfg['disk_setup'], dict)

        self.assertIsInstance(cfg['fs_setup'], list)

    def test_override_disk_aliases(self):

        # Test to make sure that the built-in DS is overriden

        builtin = DataSourceSmartOS.BUILTIN_DS_CONFIG

        mydscfg = {'disk_aliases': {'FOO': '/dev/bar'}}

        # expect that these values are in builtin, or this is pointless

        for k in mydscfg:

            self.assertIn(k, builtin)

        dsrc = self._get_ds(ds_cfg=mydscfg)

        ret = dsrc.get_data()

        self.assertTrue(ret)

        self.assertEqual(mydscfg['disk_aliases']['FOO'],

                         dsrc.ds_cfg['disk_aliases']['FOO'])

        self.assertEqual(dsrc.device_name_to_device('FOO'),

                         mydscfg['disk_aliases']['FOO'])

    def test_reconfig_network_on_boot(self):

        # Test to ensure that network is configured from metadata on each boot

        dsrc = self._get_ds(mockdata=MOCK_RETURNS)

        self.assertSetEqual(set([EventType.BOOT_NEW_INSTANCE, EventType.BOOT]),

                            dsrc.update_events['network'])

class TestIdentifyFile(CiTestCase):

    """Test the 'identify_file' utility."""

    @skipIf(not which("file"), "command 'file' not available.")

    def test_file_happy_path(self):

        """Test file is available and functional on plain text."""

        fname = self.tmp_path("myfile")

        write_file(fname, "plain text content here\n")

        with self.allow_subp(["file"]):

            self.assertEqual("text/plain", identify_file(fname))

    @mock.patch(DSMOS + ".subp.subp")

    def test_returns_none_on_error(self, m_subp):

        """On 'file' execution error, None should be returned."""

        m_subp.side_effect = ProcessExecutionError("FILE_FAILED", exit_code=99)

        fname = self.tmp_path("myfile")

        write_file(fname, "plain text content here\n")

        self.assertEqual(None, identify_file(fname))

        self.assertEqual(

            [mock.call(["file", "--brief", "--mime-type", fname])],

            m_subp.call_args_list)

class ShortReader(object):

    """Implements a 'read' interface for bytes provided.

    much like io.BytesIO but the 'endbyte' acts as if EOF.

    When it is reached a short will be returned."""

    def __init__(self, initial_bytes, endbyte=b'\0'):

        self.data = initial_bytes

        self.index = 0

        self.len = len(self.data)

        self.endbyte = endbyte

    @property

    def emptied(self):

        return self.index >= self.len

    def read(self, size=-1):

        """Read size bytes but not past a null."""

        if size == 0 or self.index >= self.len:

            return b''

        rsize = size

        if size < 0 or size + self.index > self.len:

            rsize = self.len - self.index

        next_null = self.data.find(self.endbyte, self.index, rsize)

        if next_null >= 0:

            rsize = next_null - self.index + 1

        i = self.index

        self.index += rsize

        ret = self.data[i:i + rsize]

        if len(ret) and ret[-1:] == self.endbyte:

            ret = ret[:-1]

        return ret

class TestJoyentMetadataClient(FilesystemMockingTestCase):

    invalid = b'invalid command\n'

    failure = b'FAILURE\n'

    v2_ok = b'V2_OK\n'

    def setUp(self):

        super(TestJoyentMetadataClient, self).setUp()

        self.serial = mock.MagicMock(spec=serial.Serial)

        self.request_id = 0xabcdef12

        self.metadata_value = 'value'

        self.response_parts = {

            'command': 'SUCCESS',

            'crc': 'b5a9ff00',

            'length': SUCCESS_LEN + len(b64e(self.metadata_value)),

            'payload': b64e(self.metadata_value),

            'request_id': '{0:08x}'.format(self.request_id),

        }

        def make_response():

            payloadstr = ''

            if 'payload' in self.response_parts:

                payloadstr = ' {0}'.format(self.response_parts['payload'])

            return ('V2 {length} {crc} {request_id} '

                    '{command}{payloadstr}\n'.format(

                        payloadstr=payloadstr,

                        **self.response_parts).encode('ascii'))

        self.metasource_data = None

        def read_response(length):

            if not self.metasource_data:

                self.metasource_data = make_response()

                self.metasource_data_len = len(self.metasource_data)

            resp = self.metasource_data[:length]

            self.metasource_data = self.metasource_data[length:]

            return resp

        self.serial.read.side_effect = read_response

        self.patched_funcs.enter_context(

            mock.patch('cloudinit.sources.DataSourceSmartOS.random.randint',

                       mock.Mock(return_value=self.request_id)))

    def _get_client(self):

        return DataSourceSmartOS.JoyentMetadataClient(

            fp=self.serial, smartos_type=DataSourceSmartOS.SMARTOS_ENV_KVM)

    def _get_serial_client(self):

        self.serial.timeout = 1

        return DataSourceSmartOS.JoyentMetadataSerialClient(None,

                                                            fp=self.serial)

    def assertEndsWith(self, haystack, prefix):

        self.assertTrue(haystack.endswith(prefix),

                        "{0} does not end with '{1}'".format(

                            repr(haystack), prefix))

    def assertStartsWith(self, haystack, prefix):

        self.assertTrue(haystack.startswith(prefix),

                        "{0} does not start with '{1}'".format(

                            repr(haystack), prefix))

    def assertNoMoreSideEffects(self, obj):

        self.assertRaises(StopIteration, obj)

    def test_get_metadata_writes_a_single_line(self):

        client = self._get_client()

        client.get('some_key')

        self.assertEqual(1, self.serial.write.call_count)

        written_line = self.serial.write.call_args[0][0]

        self.assertEndsWith(written_line.decode('ascii'),

                            b'\n'.decode('ascii'))

        self.assertEqual(1, written_line.count(b'\n'))

    def _get_written_line(self, key='some_key'):

        client = self._get_client()

        client.get(key)

        return self.serial.write.call_args[0][0]

    def test_get_metadata_writes_bytes(self):

        self.assertIsInstance(self._get_written_line(), bytes)

    def test_get_metadata_line_starts_with_v2(self):

        foo = self._get_written_line()

        self.assertStartsWith(foo.decode('ascii'), b'V2'.decode('ascii'))

    def test_get_metadata_uses_get_command(self):

        parts = self._get_written_line().decode('ascii').strip().split(' ')

        self.assertEqual('GET', parts[4])

    def test_get_metadata_base64_encodes_argument(self):

        key = 'my_key'

        parts = self._get_written_line(key).decode('ascii').strip().split(' ')

        self.assertEqual(b64e(key), parts[5])

    def test_get_metadata_calculates_length_correctly(self):

        parts = self._get_written_line().decode('ascii').strip().split(' ')

        expected_length = len(' '.join(parts[3:]))

        self.assertEqual(expected_length, int(parts[1]))

    def test_get_metadata_uses_appropriate_request_id(self):

        parts = self._get_written_line().decode('ascii').strip().split(' ')

        request_id = parts[3]

        self.assertEqual(8, len(request_id))

        self.assertEqual(request_id, request_id.lower())

    def test_get_metadata_uses_random_number_for_request_id(self):

        line = self._get_written_line()

        request_id = line.decode('ascii').strip().split(' ')[3]

        self.assertEqual('{0:08x}'.format(self.request_id), request_id)

    def test_get_metadata_checksums_correctly(self):

        parts = self._get_written_line().decode('ascii').strip().split(' ')

        expected_checksum = '{0:08x}'.format(

            crc32(' '.join(parts[3:]).encode('utf-8')) & 0xffffffff)

        checksum = parts[2]

        self.assertEqual(expected_checksum, checksum)

    def test_get_metadata_reads_a_line(self):

        client = self._get_client()

        client.get('some_key')

        self.assertEqual(self.metasource_data_len, self.serial.read.call_count)

    def test_get_metadata_returns_valid_value(self):

        client = self._get_client()

        value = client.get('some_key')

        self.assertEqual(self.metadata_value, value)

    def test_get_metadata_throws_exception_for_incorrect_length(self):

        self.response_parts['length'] = 0

        client = self._get_client()

        self.assertRaises(DataSourceSmartOS.JoyentMetadataFetchException,

                          client.get, 'some_key')

    def test_get_metadata_throws_exception_for_incorrect_crc(self):

        self.response_parts['crc'] = 'deadbeef'

        client = self._get_client()

        self.assertRaises(DataSourceSmartOS.JoyentMetadataFetchException,

                          client.get, 'some_key')

    def test_get_metadata_throws_exception_for_request_id_mismatch(self):

        self.response_parts['request_id'] = 'deadbeef'

        client = self._get_client()

        client._checksum = lambda _: self.response_parts['crc']

        self.assertRaises(DataSourceSmartOS.JoyentMetadataFetchException,

                          client.get, 'some_key')

    def test_get_metadata_returns_None_if_value_not_found(self):

        self.response_parts['payload'] = ''

        self.response_parts['command'] = 'NOTFOUND'

        self.response_parts['length'] = NOTFOUND_LEN

        client = self._get_client()

        client._checksum = lambda _: self.response_parts['crc']

        self.assertIsNone(client.get('some_key'))

    def test_negotiate(self):

        client = self._get_client()

        reader = ShortReader(self.v2_ok)

        client.fp.read.side_effect = reader.read

        client._negotiate()

        self.assertTrue(reader.emptied)

    def test_negotiate_short_response(self):