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# Author: Vaidas Jablonskis <jablonskis@gmail.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
from base64 import b64decode
from cloudinit import log as logging
from cloudinit import sources
from cloudinit import url_helper
from cloudinit import util
LOG = logging.getLogger(__name__)
MD_V1_URL = 'http://metadata.google.internal/computeMetadata/v1/'
BUILTIN_DS_CONFIG = {'metadata_url': MD_V1_URL}
REQUIRED_FIELDS = ('instance-id', 'availability-zone', 'local-hostname')
class GoogleMetadataFetcher(object):
headers = {'X-Google-Metadata-Request': 'True'}
def __init__(self, metadata_address):
self.metadata_address = metadata_address
def get_value(self, path, is_text):
value = None
try:
resp = url_helper.readurl(url=self.metadata_address + path,
headers=self.headers)
except url_helper.UrlError as exc:
msg = "url %s raised exception %s"
LOG.debug(msg, path, exc)
else:
if resp.code == 200:
if is_text:
value = util.decode_binary(resp.contents)
else:
value = resp.contents
else:
LOG.debug("url %s returned code %s", path, resp.code)
return value
class DataSourceGCE(sources.DataSource):
dsname = 'GCE'
def __init__(self, sys_cfg, distro, paths):
sources.DataSource.__init__(self, sys_cfg, distro, paths)
self.metadata = dict()
self.ds_cfg = util.mergemanydict([
util.get_cfg_by_path(sys_cfg, ["datasource", "GCE"], {}),
BUILTIN_DS_CONFIG])
self.metadata_address = self.ds_cfg['metadata_url']
def _get_data(self):
ret = util.log_time(
LOG.debug, 'Crawl of GCE metadata service',
read_md, kwargs={'address': self.metadata_address})
if not ret['success']:
if ret['platform_reports_gce']:
LOG.warning(ret['reason'])
else:
LOG.debug(ret['reason'])
return False
self.metadata = ret['meta-data']
self.userdata_raw = ret['user-data']
return True
@property
def launch_index(self):
# GCE does not provide lauch_index property
return None
def get_instance_id(self):
return self.metadata['instance-id']
def get_public_ssh_keys(self):
return self.metadata['public-keys']
def get_hostname(self, fqdn=False, resolve_ip=False):
# GCE has long FDQN's and has asked for short hostnames
return self.metadata['local-hostname'].split('.')[0]
@property
def availability_zone(self):
return self.metadata['availability-zone']
@property
def region(self):
return self.availability_zone.rsplit('-', 1)[0]
def _trim_key(public_key):
# GCE takes sshKeys attribute in the format of '<user>:<public_key>'
# so we have to trim each key to remove the username part
try:
index = public_key.index(':')
if index > 0:
return public_key[(index + 1):]
except Exception:
return public_key
def read_md(address=None, platform_check=True):
if address is None:
address = MD_V1_URL
ret = {'meta-data': None, 'user-data': None,
'success': False, 'reason': None}
ret['platform_reports_gce'] = platform_reports_gce()
if platform_check and not ret['platform_reports_gce']:
ret['reason'] = "Not running on GCE."
return ret
# if we cannot resolve the metadata server, then no point in trying
if not util.is_resolvable_url(address):
LOG.debug("%s is not resolvable", address)
ret['reason'] = 'address "%s" is not resolvable' % address
return ret
# url_map: (our-key, path, required, is_text)
url_map = [
('instance-id', ('instance/id',), True, True),
('availability-zone', ('instance/zone',), True, True),
('local-hostname', ('instance/hostname',), True, True),
('public-keys', ('project/attributes/sshKeys',
'instance/attributes/ssh-keys'), False, True),
('user-data', ('instance/attributes/user-data',), False, False),
('user-data-encoding', ('instance/attributes/user-data-encoding',),
False, True),
]
metadata_fetcher = GoogleMetadataFetcher(address)
md = {}
# iterate over url_map keys to get metadata items
for (mkey, paths, required, is_text) in url_map:
value = None
for path in paths:
new_value = metadata_fetcher.get_value(path, is_text)
if new_value is not None:
value = new_value
if required and value is None:
msg = "required key %s returned nothing. not GCE"
ret['reason'] = msg % mkey
return ret
md[mkey] = value
if md['public-keys']:
lines = md['public-keys'].splitlines()
md['public-keys'] = [_trim_key(k) for k in lines]
if md['availability-zone']:
md['availability-zone'] = md['availability-zone'].split('/')[-1]
encoding = md.get('user-data-encoding')
if encoding:
if encoding == 'base64':
md['user-data'] = b64decode(md['user-data'])
else:
LOG.warning('unknown user-data-encoding: %s, ignoring', encoding)
if 'user-data' in md:
ret['user-data'] = md['user-data']
del md['user-data']
ret['meta-data'] = md
ret['success'] = True
return ret
def platform_reports_gce():
pname = util.read_dmi_data('system-product-name') or "N/A"
if pname == "Google Compute Engine":
return True
# system-product-name is not always guaranteed (LP: #1674861)
serial = util.read_dmi_data('system-serial-number') or "N/A"
if serial.startswith("GoogleCloud-"):
return True
LOG.debug("Not running on google cloud. product-name=%s serial=%s",
pname, serial)
return False
# Used to match classes to dependencies
datasources = [
(DataSourceGCE, (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)
if __name__ == "__main__":
import argparse
import json
import sys
from base64 import b64encode
parser = argparse.ArgumentParser(description='Query GCE Metadata Service')
parser.add_argument("--endpoint", metavar="URL",
help="The url of the metadata service.",
default=MD_V1_URL)
parser.add_argument("--no-platform-check", dest="platform_check",
help="Ignore smbios platform check",
action='store_false', default=True)
args = parser.parse_args()
data = read_md(address=args.endpoint, platform_check=args.platform_check)
if 'user-data' in data:
# user-data is bytes not string like other things. Handle it specially.
# if it can be represented as utf-8 then do so. Otherwise print base64
# encoded value in the key user-data-b64.
try:
data['user-data'] = data['user-data'].decode()
except UnicodeDecodeError:
sys.stderr.write("User-data cannot be decoded. "
"Writing as base64\n")
del data['user-data']
# b64encode returns a bytes value. decode to get the string.
data['user-data-b64'] = b64encode(data['user-data']).decode()
print(json.dumps(data, indent=1, sort_keys=True, separators=(',', ': ')))
# vi: ts=4 expandtab
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