summaryrefslogtreecommitdiff
path: root/cloudinit/sources/DataSourceEc2.py
blob: 0598dfa2e620da282059de14d5e6f222dc3d5c5e (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
# vi: ts=4 expandtab
#
#    Copyright (C) 2009-2010 Canonical Ltd.
#    Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
#    Copyright (C) 2012 Yahoo! Inc.
#
#    Author: Scott Moser <scott.moser@canonical.com>
#    Author: Juerg Hafliger <juerg.haefliger@hp.com>
#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, as
#    published by the Free Software Foundation.
#
#    This program is distributed in the hope that it will be useful,
#    but WITHOUT ANY WARRANTY; without even the implied warranty of
#    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#    GNU General Public License for more details.
#
#    You should have received a copy of the GNU General Public License
#    along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os
import time

import boto.utils as boto_utils

from cloudinit import log as logging
from cloudinit import sources
from cloudinit import url_helper as uhelp
from cloudinit import util

LOG = logging.getLogger(__name__)

DEF_MD_URL = "http://169.254.169.254"

# Which version we are requesting of the ec2 metadata apis
DEF_MD_VERSION = '2009-04-04'

# Default metadata urls that will be used if none are provided
# They will be checked for 'resolveability' and some of the
# following may be discarded if they do not resolve
DEF_MD_URLS = [DEF_MD_URL, "http://instance-data:8773"]


class DataSourceEc2(sources.DataSource):
    def __init__(self, sys_cfg, distro, paths):
        sources.DataSource.__init__(self, sys_cfg, distro, paths)
        self.metadata_address = DEF_MD_URL
        self.seed_dir = os.path.join(paths.seed_dir, "ec2")
        self.api_ver = DEF_MD_VERSION

    def __str__(self):
        return util.obj_name(self)

    def get_data(self):
        seed_ret = {}
        if util.read_optional_seed(seed_ret, base=(self.seed_dir + "/")):
            self.userdata_raw = seed_ret['user-data']
            self.metadata = seed_ret['meta-data']
            LOG.debug("Using seeded ec2 data from %s", self.seed_dir)
            return True

        try:
            if not self.wait_for_metadata_service():
                return False
            start_time = time.time()
            self.userdata_raw = boto_utils.get_instance_userdata(self.api_ver,
                None, self.metadata_address)
            self.metadata = boto_utils.get_instance_metadata(self.api_ver,
                self.metadata_address)
            LOG.debug("Crawl of metadata service took %s seconds",
                       int(time.time() - start_time))
            return True
        except Exception:
            util.logexc(LOG, "Failed reading from metadata address %s",
                        self.metadata_address)
            return False

    def get_instance_id(self):
        return self.metadata['instance-id']

    def get_availability_zone(self):
        return self.metadata['placement']['availability-zone']

    def get_local_mirror(self):
        return self.get_mirror_from_availability_zone()

    def get_mirror_from_availability_zone(self, availability_zone=None):
        # Availability is like 'us-west-1b' or 'eu-west-1a'
        if availability_zone is None:
            availability_zone = self.get_availability_zone()

        if self.is_vpc():
            return None

        # Use the distro to get the mirror
        if not availability_zone:
            return None

        mirror_tpl = self.distro.get_option('availability_zone_template')
        if not mirror_tpl:
            return None

        tpl_params = {
            'zone': availability_zone.strip(),
        }
        mirror_url = mirror_tpl % (tpl_params)

        (max_wait, timeout) = self._get_url_settings()
        worked = uhelp.wait_for_url([mirror_url], max_wait=max_wait,
                                timeout=timeout, status_cb=LOG.warn)
        if not worked:
            return None

        return mirror_url

    def _get_url_settings(self):
        mcfg = self.ds_cfg
        if not mcfg:
            mcfg = {}
        max_wait = 120
        try:
            max_wait = int(mcfg.get("max_wait", max_wait))
        except Exception:
            util.logexc(LOG, "Failed to get max wait. using %s", max_wait)

        if max_wait == 0:
            return False

        timeout = 50
        try:
            timeout = int(mcfg.get("timeout", timeout))
        except Exception:
            util.logexc(LOG, "Failed to get timeout, using %s", timeout)

        return (max_wait, timeout)

    def wait_for_metadata_service(self):
        mcfg = self.ds_cfg
        if not mcfg:
            mcfg = {}

        (max_wait, timeout) = self._get_url_settings()

        # Remove addresses from the list that wont resolve.
        mdurls = mcfg.get("metadata_urls", DEF_MD_URLS)
        filtered = [x for x in mdurls if util.is_resolvable_url(x)]

        if set(filtered) != set(mdurls):
            LOG.debug("Removed the following from metadata urls: %s",
                      list((set(mdurls) - set(filtered))))

        if len(filtered):
            mdurls = filtered
        else:
            LOG.warn("Empty metadata url list! using default list")
            mdurls = DEF_MD_URLS

        urls = []
        url2base = {}
        for url in mdurls:
            cur = "%s/%s/meta-data/instance-id" % (url, self.api_ver)
            urls.append(cur)
            url2base[cur] = url

        start_time = time.time()
        url = uhelp.wait_for_url(urls=urls, max_wait=max_wait,
                                timeout=timeout, status_cb=LOG.warn)

        if url:
            LOG.info("Using metadata source: '%s'", url2base[url])
        else:
            LOG.critical("Giving up on md from %s after %s seconds",
                            urls, int(time.time() - start_time))

        self.metadata_address = url2base.get(url)
        return bool(url)

    def _remap_device(self, short_name):
        # LP: #611137
        # the metadata service may believe that devices are named 'sda'
        # when the kernel named them 'vda' or 'xvda'
        # we want to return the correct value for what will actually
        # exist in this instance
        mappings = {"sd": ("vd", "xvd")}
        for (nfrom, tlist) in mappings.iteritems():
            if not short_name.startswith(nfrom):
                continue
            for nto in tlist:
                cand = "/dev/%s%s" % (nto, short_name[len(nfrom):])
                if os.path.exists(cand):
                    return cand
        return None

    def device_name_to_device(self, name):
        # Consult metadata service, that has
        #  ephemeral0: sdb
        # and return 'sdb' for input 'ephemeral0'
        if 'block-device-mapping' not in self.metadata:
            return None

        # Example:
        # 'block-device-mapping':
        # {'ami': '/dev/sda1',
        # 'ephemeral0': '/dev/sdb',
        # 'root': '/dev/sda1'}
        found = None
        bdm_items = self.metadata['block-device-mapping'].iteritems()
        for (entname, device) in bdm_items:
            if entname == name:
                found = device
                break
            # LP: #513842 mapping in Euca has 'ephemeral' not 'ephemeral0'
            if entname == "ephemeral" and name == "ephemeral0":
                found = device

        if found is None:
            LOG.debug("Unable to convert %s to a device", name)
            return None

        ofound = found
        if not found.startswith("/"):
            found = "/dev/%s" % found

        if os.path.exists(found):
            return found

        remapped = self._remap_device(os.path.basename(found))
        if remapped:
            LOG.debug("Remapped device name %s => %s", (found, remapped))
            return remapped

        # On t1.micro, ephemeral0 will appear in block-device-mapping from
        # metadata, but it will not exist on disk (and never will)
        # at this point, we've verified that the path did not exist
        # in the special case of 'ephemeral0' return None to avoid bogus
        # fstab entry (LP: #744019)
        if name == "ephemeral0":
            return None
        return ofound

    def is_vpc(self):
        # See: https://bugs.launchpad.net/ubuntu/+source/cloud-init/+bug/615545
        # Detect that the machine was launched in a VPC.
        # But I did notice that when in a VPC, meta-data
        # does not have public-ipv4 and public-hostname
        # listed as a possibility.
        ph = "public-hostname"
        p4 = "public-ipv4"
        if ((ph not in self.metadata or self.metadata[ph] == "") and
            (p4 not in self.metadata or self.metadata[p4] == "")):
            return True
        return False


# Used to match classes to dependencies
datasources = [
  (DataSourceEc2, (sources.DEP_FILESYSTEM, sources.DEP_NETWORK)),
]


# Return a list of data sources that match this set of dependencies
def get_datasource_list(depends):
    return sources.list_from_depends(depends, datasources)