diff options
Diffstat (limited to 'cloudinit/sources/DataSourceSmartOS.py')
| -rw-r--r-- | cloudinit/sources/DataSourceSmartOS.py | 89 |
1 files changed, 69 insertions, 20 deletions
diff --git a/cloudinit/sources/DataSourceSmartOS.py b/cloudinit/sources/DataSourceSmartOS.py index 9d48beab..c9b497df 100644 --- a/cloudinit/sources/DataSourceSmartOS.py +++ b/cloudinit/sources/DataSourceSmartOS.py @@ -29,9 +29,12 @@ # http://us-east.manta.joyent.com/jmc/public/mdata/datadict.html # Comments with "@datadictionary" are snippets of the definition -import base64 import binascii +import contextlib import os +import random +import re + import serial from cloudinit import log as logging @@ -301,6 +304,65 @@ def get_serial(seed_device, seed_timeout): return ser +class JoyentMetadataFetchException(Exception): + pass + + +class JoyentMetadataClient(object): + """ + A client implementing v2 of the Joyent Metadata Protocol Specification. + + The full specification can be found at + http://eng.joyent.com/mdata/protocol.html + """ + line_regex = re.compile( + r'V2 (?P<length>\d+) (?P<checksum>[0-9a-f]+)' + r' (?P<body>(?P<request_id>[0-9a-f]+) (?P<status>SUCCESS|NOTFOUND)' + r'( (?P<payload>.+))?)') + + def __init__(self, serial): + self.serial = serial + + def _checksum(self, body): + return '{0:08x}'.format( + binascii.crc32(body.encode('utf-8')) & 0xffffffff) + + def _get_value_from_frame(self, expected_request_id, frame): + frame_data = self.line_regex.match(frame).groupdict() + if int(frame_data['length']) != len(frame_data['body']): + raise JoyentMetadataFetchException( + 'Incorrect frame length given ({0} != {1}).'.format( + frame_data['length'], len(frame_data['body']))) + expected_checksum = self._checksum(frame_data['body']) + if frame_data['checksum'] != expected_checksum: + raise JoyentMetadataFetchException( + 'Invalid checksum (expected: {0}; got {1}).'.format( + expected_checksum, frame_data['checksum'])) + if frame_data['request_id'] != expected_request_id: + raise JoyentMetadataFetchException( + 'Request ID mismatch (expected: {0}; got {1}).'.format( + expected_request_id, frame_data['request_id'])) + if not frame_data.get('payload', None): + LOG.debug('No value found.') + return None + value = util.b64d(frame_data['payload']) + LOG.debug('Value "%s" found.', value) + return value + + def get_metadata(self, metadata_key): + LOG.debug('Fetching metadata key "%s"...', metadata_key) + request_id = '{0:08x}'.format(random.randint(0, 0xffffffff)) + message_body = '{0} GET {1}'.format(request_id, + util.b64e(metadata_key)) + msg = 'V2 {0} {1} {2}\n'.format( + len(message_body), self._checksum(message_body), message_body) + LOG.debug('Writing "%s" to serial port.', msg) + self.serial.write(msg.encode('ascii')) + response = self.serial.readline().decode('ascii') + LOG.debug('Read "%s" from serial port.', response) + return self._get_value_from_frame(request_id, response) + + def query_data(noun, seed_device, seed_timeout, strip=False, default=None, b64=None): """Makes a request to via the serial console via "GET <NOUN>" @@ -314,33 +376,20 @@ def query_data(noun, seed_device, seed_timeout, strip=False, default=None, encoded, so this method relies on being told if the data is base64 or not. """ - if not noun: return False - ser = get_serial(seed_device, seed_timeout) - ser.write("GET %s\n" % noun.rstrip()) - status = str(ser.readline()).rstrip() - response = [] - eom_found = False + with contextlib.closing(get_serial(seed_device, seed_timeout)) as ser: + client = JoyentMetadataClient(ser) + response = client.get_metadata(noun) - if 'SUCCESS' not in status: - ser.close() + if response is None: return default - while not eom_found: - m = ser.readline() - if m.rstrip() == ".": - eom_found = True - else: - response.append(m) - - ser.close() - if b64 is None: b64 = query_data('b64-%s' % noun, seed_device=seed_device, - seed_timeout=seed_timeout, b64=False, - default=False, strip=True) + seed_timeout=seed_timeout, b64=False, + default=False, strip=True) b64 = util.is_true(b64) resp = None |