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