def get_data(self):
try:
if not self.wait_for_metadata_service():
return False
start = time.time()
log.info("Calling into metadata service using boto at: %s", self.metadata_address)
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" % (time.time() - start))
log.debug("Received raw userdata: %s", self.userdata_raw)
log.debug("Received metadata: %s", self.metadata)
return True
except Exception:
return False
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 unresolveable addrs from metadata urls: %s" % list((set(mdurls) - set(filtered)))
)
if len(filtered):
mdurls = filtered
else:
log.warn("Empty metadata url list! using default list %s", def_mdurls)
mdurls = def_mdurls
urls = []
url2base = {}
for url in mdurls:
cur = "%s/%s/meta-data/instance-id" % (url, self.api_ver)
urls.append(cur)
url2base[cur] = url
starttime = time.time()
def status_cb(url, why, details):
log.warn("Calling %r failed due to %r: %s", url, why, details)
url = wait_for_metadata_service(urls=urls, max_wait=max_wait, timeout=timeout, status_cb=status_cb)
if url:
log.info("Using metadata source: '%s'" % url2base.get(url))
else:
log.critical("Giving up on metadata fetching after %i seconds" % int(time.time() - starttime))
self.metadata_address = url2base.get(url) or False
return bool(url)
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(url, why, details):
return
if not status_cb:
status_cb = nullstatus_cb
def timeup(max_wait, starttime):
return (max_wait <= 0 or max_wait == None) or (time.time() - starttime > max_wait)
log.info("Waiting for meta service at urls %s [maxwait=%s, timeout=%s]", urls, max_wait, timeout)
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
details = "[%s/%ss]" % (int(time.time() - starttime), max_wait)
status_cb(url, reason, details)
if timeup(max_wait, starttime):
break
loop_n = loop_n + 1
time.sleep(sleeptime)
return False
