x/cloud-init
Code Issues Proposed changes
cloud-init/cloudinit/DataSourceEc2.py
Scott Moser ccdf959986 Add HP to Copyright, and Juerg Haefliger Authors. 
This copyright change reflects previous changes that Juerg made for pylint and
pep8 cleanups.

From: Juerg Haefliger <juerg.haefliger@hp.com>
Date: Mon, 16 Jan 2012 10:45:12 +0100
2012-01-18 09:07:33 -05:00

300 lines
10 KiB
Python
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# vi: ts=4 expandtab
#
# Copyright (C) 2009-2010 Canonical Ltd.
# Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
#
# Author: Scott Moser <scott.moser@canonical.com>
# Author: Juerg Hafliger <juerg.haefliger@hp.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 cloudinit.DataSource as DataSource
from cloudinit import seeddir as base_seeddir
from cloudinit import log
import cloudinit.util as util
import socket
import urllib2
import time
import boto.utils as boto_utils
import os.path
class DataSourceEc2(DataSource.DataSource):
api_ver = '2009-04-04'
seeddir = base_seeddir + '/ec2'
metadata_address = "http://169.254.169.254"
def __str__(self):
return("DataSourceEc2")
def get_data(self):
seedret = {}
if util.read_optional_seed(seedret, base=self.seeddir + "/"):
self.userdata_raw = seedret['user-data']
self.metadata = seedret['meta-data']
log.debug("using seeded ec2 data in %s" % self.seeddir)
return True
try:
if not self.wait_for_metadata_service():
return False
start = 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 %ds" % (time.time() -
start))
return True
except Exception as e:
print e
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 == None:
availability_zone = self.get_availability_zone()
fallback = None
if self.is_vpc():
return fallback
try:
host = "%s.ec2.archive.ubuntu.com" % availability_zone[:-1]
socket.getaddrinfo(host, None, 0, socket.SOCK_STREAM)
return 'http://%s/ubuntu/' % host
except:
return fallback
def wait_for_metadata_service(self):
mcfg = self.ds_cfg
if not hasattr(mcfg, "get"):
mcfg = {}
max_wait = 120
try:
max_wait = int(mcfg.get("max_wait", max_wait))
except Exception:
util.logexc(log)
log.warn("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)
log.warn("Failed to get timeout, using %s" % timeout)
def_mdurls = ["http://169.254.169.254", "http://instance-data:8773"]
mdurls = mcfg.get("metadata_urls", def_mdurls)
# Remove addresses from the list that wont resolve.
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_mdurls
urls = []
url2base = {False: False}
for url in mdurls:
cur = "%s/%s/meta-data/instance-id" % (url, self.api_ver)
urls.append(cur)
url2base[cur] = url
starttime = time.time()
url = wait_for_metadata_service(urls=urls, max_wait=max_wait,
timeout=timeout, status_cb=log.warn)
if url:
log.debug("Using metadata source: '%s'" % url2base[url])
else:
log.critical("giving up on md after %i seconds\n" %
int(time.time() - starttime))
self.metadata_address = url2base[url]
return (bool(url))
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)
found = None
for entname, device in self.metadata['block-device-mapping'].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 == None:
log.debug("unable to convert %s to a device" % name)
return None
# 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")}
ofound = found
short = os.path.basename(found)
if not found.startswith("/"):
found = "/dev/%s" % found
if os.path.exists(found):
return(found)
for nfrom, tlist in mappings.items():
if not short.startswith(nfrom):
continue
for nto in tlist:
cand = "/dev/%s%s" % (nto, short[len(nfrom):])
if os.path.exists(cand):
log.debug("remapped device name %s => %s" % (found, cand))
return(cand)
# on t1.micro, ephemeral0 will appear in block-device-mapping from
# metadata, but it will not exist on disk (and never will)
# at this pint, 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):
# per comment in LP: #615545
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
def wait_for_metadata_service(urls, max_wait=None, timeout=None,
status_cb=None):
"""
urls: a list of urls to try
max_wait: roughly the maximum time to wait before giving up
The max time is *actually* len(urls)*timeout as each url will
be tried once and given the timeout provided.
timeout: the timeout provided to urllib2.urlopen
status_cb: call method with string message when a url is not available
the idea of this routine is to wait for the EC2 metdata service to
come up. On both Eucalyptus and EC2 we have seen the case where
the instance hit the MD before the MD service was up. EC2 seems
to have permenantely fixed this, though.
In openstack, the metadata service might be painfully slow, and
unable to avoid hitting a timeout of even up to 10 seconds or more
(LP: #894279) for a simple GET.
Offset those needs with the need to not hang forever (and block boot)
on a system where cloud-init is configured to look for EC2 Metadata
service but is not going to find one. It is possible that the instance
data host (169.254.169.254) may be firewalled off Entirely for a sytem,
meaning that the connection will block forever unless a timeout is set.
"""
starttime = time.time()
sleeptime = 1
def nullstatus_cb(msg):
return
if status_cb == None:
status_cb = nullstatus_cb
def timeup(max_wait, starttime):
return((max_wait <= 0 or max_wait == None) or
(time.time() - starttime > max_wait))
loop_n = 0
while True:
sleeptime = int(loop_n / 5) + 1
for url in urls:
now = time.time()
if loop_n != 0:
if timeup(max_wait, starttime):
break
if timeout and (now + timeout > (starttime + max_wait)):
# shorten timeout to not run way over max_time
timeout = int((starttime + max_wait) - now)
reason = ""
try:
req = urllib2.Request(url)
resp = urllib2.urlopen(req, timeout=timeout)
if resp.read() != "":
return url
reason = "empty data [%s]" % resp.getcode()
except urllib2.HTTPError as e:
reason = "http error [%s]" % e.code
except urllib2.URLError as e:
reason = "url error [%s]" % e.reason
except socket.timeout as e:
reason = "socket timeout [%s]" % e
except Exception as e:
reason = "unexpected error [%s]" % e
if log:
status_cb("'%s' failed [%s/%ss]: %s" %
(url, int(time.time() - starttime), max_wait,
reason))
if timeup(max_wait, starttime):
break
loop_n = loop_n + 1
time.sleep(sleeptime)
return False
datasources = [
(DataSourceEc2, (DataSource.DEP_FILESYSTEM, DataSource.DEP_NETWORK)),
]
# return a list of data sources that match this set of dependencies
def get_datasource_list(depends):
return(DataSource.list_from_depends(depends, datasources))
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