deb-glance/bin/glance-replicator
Michael Still 7335088d89 Handle images which exist but can't be seen.
If the master and the slave glance have different permissions, you
can end up with a 409 exception at upload. For example:

 - the image is visible to the replication user on the master
 - the image is present on the slave, but not visible to the
   replication user

The replicator checks for the existance of the image by doing a HEAD
on http://server:port/v1/images/uuid and gets a 404 back. It therefore
decides the image doesn't exist and that it should be replicated. It
does a POST for that URL, and gets a 409 back saying that UUID is
already in use.

Resolves bug 1030396.

Change-Id: Id5fdb7977692593fd6c2e203f0440d4aa5339d92
2012-08-04 10:36:06 +10:00

706 lines
25 KiB
Python
Executable File

#!/usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4
# Copyright 2012 Michael Still and Canonical Inc
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import gettext
import httplib
import json
import logging
import logging.config
import logging.handlers
import optparse
import os
import sys
import urllib
import uuid
# If ../glance/__init__.py exists, add ../ to Python search path, so that
# it will override what happens to be installed in /usr/(local/)lib/python...
possible_topdir = os.path.normpath(os.path.join(os.path.abspath(sys.argv[0]),
os.pardir,
os.pardir))
if os.path.exists(os.path.join(possible_topdir, 'glance', '__init__.py')):
sys.path.insert(0, possible_topdir)
gettext.install('glance', unicode=1)
COMMANDS = """Commands:
help <command> Output help for one of the commands below
compare What is missing from the slave glance?
dump Dump the contents of a glance instance to local disk.
livecopy Load the contents of one glance instance into another.
load Load the contents of a local directory into glance.
size Determine the size of a glance instance if dumped to disk.
"""
IMAGE_ALREADY_PRESENT_MESSAGE = _('The image %s is already present on '
'the slave, but our check for it did '
'not find it. This indicates that we '
'do not have permissions to see all '
'the images on the slave server.')
class AuthenticationException(Exception):
pass
class ImageAlreadyPresentException(Exception):
pass
class ServerErrorException(Exception):
pass
class UploadException(Exception):
pass
class ImageService(object):
def __init__(self, conn, auth_token):
""" Initialize the ImageService.
conn: a httplib.HTTPConnection to the glance server
auth_token: authentication token to pass in the x-auth-token header
"""
self.auth_token = auth_token
self.conn = conn
def _http_request(self, method, url, headers, body,
ignore_result_body=False):
"""Perform an HTTP request against the server.
method: the HTTP method to use
url: the URL to request (not including server portion)
headers: headers for the request
body: body to send with the request
ignore_result_body: the body of the result will be ignored
Returns: a httplib response object
"""
if self.auth_token:
headers.setdefault('x-auth-token', self.auth_token)
logging.debug(_('Request: %(method)s http://%(server)s:%(port)s'
'%(url)s with headers %(headers)s')
% {'method': method,
'server': self.conn.host,
'port': self.conn.port,
'url': url,
'headers': repr(headers)})
self.conn.request(method, url, body, headers)
response = self.conn.getresponse()
headers = self._header_list_to_dict(response.getheaders())
code = response.status
code_description = httplib.responses[code]
logging.debug(_('Response: %(code)s %(status)s %(headers)s')
% {'code': code,
'status': code_description,
'headers': repr(headers)})
if code in [400, 500]:
raise ServerErrorException(response.read())
if code in [401, 403]:
raise AuthenticationException(response.read())
if code == 409:
raise ImageAlreadyPresentException(response.read())
if ignore_result_body:
# NOTE: because we are pipelining requests through a single HTTP
# connection, httplib requires that we read the response body
# before we can make another request. If the caller knows they
# don't care about the body, they can ask us to do that for them.
response.read()
return response
def get_images(self):
"""Return a detailed list of images.
Yields a series of images as dicts containing metadata.
"""
params = {'is_public': None}
while True:
url = '/v1/images/detail'
query = urllib.urlencode(params)
if query:
url += '?%s' % query
response = self._http_request('GET', url, {}, '')
result = json.loads(response.read())
if not result or not 'images' in result or not result['images']:
return
for image in result.get('images', []):
params['marker'] = image['id']
yield image
def get_image(self, image_uuid):
"""Fetch image data from glance.
image_uuid: the id of an image
Returns: a httplib Response object where the body is the image.
"""
url = '/v1/images/%s' % image_uuid
return self._http_request('GET', url, {}, '')
@staticmethod
def _header_list_to_dict(headers):
"""Expand a list of headers into a dictionary.
headers: a list of [(key, value), (key, value), (key, value)]
Returns: a dictionary representation of the list
"""
d = {}
for (header, value) in headers:
if header.startswith('x-image-meta-property-'):
prop = header.replace('x-image-meta-properties', '')
d.setdefault('properties', {})
d['properties'][prop] = value
else:
d[header.replace('x-image-meta-', '')] = value
return d
def get_image_meta(self, image_uuid):
"""Return the metadata for a single image.
image_uuid: the id of an image
Returns: image metadata as a dictionary
"""
url = '/v1/images/%s' % image_uuid
response = self._http_request('HEAD', url, {}, '',
ignore_result_body=True)
return self._header_list_to_dict(response.getheaders())
@staticmethod
def _dict_to_headers(d):
"""Convert a dictionary into one suitable for a HTTP request.
d: a dictionary
Returns: the same dictionary, with x-image-meta added to every key
"""
h = {}
for key in d:
if key == 'properties':
for subkey in d[key]:
h['x-image-meta-property-%s' % subkey] = d[key][subkey]
else:
h['x-image-meta-%s' % key] = d[key]
return h
def add_image(self, image_meta, image_data):
"""Upload an image.
image_meta: image metadata as a dictionary
image_data: image data as a object with a read() method
Returns: a tuple of (http response headers, http response body)
"""
url = '/v1/images'
headers = self._dict_to_headers(image_meta)
headers['Content-Type'] = 'application/octet-stream'
headers['Content-Length'] = int(image_meta['size'])
response = self._http_request('POST', url, headers, image_data)
headers = self._header_list_to_dict(response.getheaders())
logging.debug(_('Image post done'))
body = response.read()
return headers, body
def add_image_meta(self, image_meta):
"""Update image metadata.
image_meta: image metadata as a dictionary
Returns: a tuple of (http response headers, http response body)
"""
url = '/v1/images/%s' % image_meta['id']
headers = self._dict_to_headers(image_meta)
headers['Content-Type'] = 'application/octet-stream'
response = self._http_request('PUT', url, headers, '')
headers = self._header_list_to_dict(response.getheaders())
logging.debug(_('Image post done'))
body = response.read()
return headers, body
def replication_size(options, args):
"""%(prog)s size <server:port>
Determine the size of a glance instance if dumped to disk.
server:port: the location of the glance instance.
"""
server_port = args.pop()
server, port = server_port.split(':')
total_size = 0
count = 0
client = ImageService(httplib.HTTPConnection(server, port),
options.slavetoken)
for image in client.get_images():
logging.debug(_('Considering image: %(image)s') % {'image': image})
if image['status'] == 'active':
total_size += int(image['size'])
count += 1
print _('Total size is %d bytes across %d images') % (total_size, count)
def replication_dump(options, args):
"""%(prog)s dump <server:port> <path>
Dump the contents of a glance instance to local disk.
server:port: the location of the glance instance.
path: a directory on disk to contain the data.
"""
path = args.pop()
server_port = args.pop()
server, port = server_port.split(':')
client = ImageService(httplib.HTTPConnection(server, port),
options.mastertoken)
for image in client.get_images():
logging.info(_('Considering: %s' % image['id']))
data_path = os.path.join(path, image['id'])
if not os.path.exists(data_path):
logging.info(_('... storing'))
# Dump glance information
with open(data_path, 'w') as f:
f.write(json.dumps(image))
if image['status'] == 'active' and not options.metaonly:
# Now fetch the image. The metadata returned in headers here
# is the same as that which we got from the detailed images
# request earlier, so we can ignore it here. Note that we also
# only dump active images.
logging.info(_('... image is active'))
image_response = client.get_image(image['id'])
with open(data_path + '.img', 'wb') as f:
while True:
chunk = image_response.read(options.chunksize)
if not chunk:
break
f.write(chunk)
def _dict_diff(a, b):
"""A one way dictionary diff.
a: a dictionary
b: a dictionary
Returns: True if the dictionaries are different
"""
# Only things the master has which the slave lacks matter
if set(a.keys()) - set(b.keys()):
logging.debug(_('metadata diff -- master has extra keys: %(keys)s')
% {'keys': ' '.join(set(a.keys()) - set(b.keys()))})
return True
for key in a:
if str(a[key]) != str(b[key]):
logging.debug(_('metadata diff -- value differs for key '
'%(key)s: master "%(master_value)s" vs '
'slave "%(slave_value)s"')
% {'key': key,
'master_value': a[key],
'slave_value': b[key]})
return True
return False
# This is lifted from openstack-common, but copied here to reduce dependancies
def is_uuid_like(value):
try:
uuid.UUID(value)
return True
except Exception:
return False
def replication_load(options, args):
"""%(prog)s load <server:port> <path>
Load the contents of a local directory into glance.
server:port: the location of the glance instance.
path: a directory on disk containing the data.
"""
path = args.pop()
server_port = args.pop()
server, port = server_port.split(':')
client = ImageService(httplib.HTTPConnection(server, port),
options.slavetoken)
for ent in os.listdir(path):
if is_uuid_like(ent):
image_uuid = ent
logging.info(_('Considering: %s') % image_uuid)
meta_file_name = os.path.join(path, image_uuid)
with open(meta_file_name) as meta_file:
meta = json.loads(meta_file.read())
# Remove keys which don't make sense for replication
for key in options.dontreplicate.split(' '):
if key in meta:
logging.debug(_('Stripping %(header)s from saved '
'metadata'), {'header': key})
del meta[key]
if _image_present(client, image_uuid):
# NOTE(mikal): Perhaps we just need to update the metadata?
# Note that we don't attempt to change an image file once it
# has been uploaded.
headers = client.get_image_meta(image_uuid)
for key in options.dontreplicate.split(' '):
if key in headers:
logging.debug(_('Stripping %(header)s from slave '
'metadata'), {'header': key})
del headers[key]
if _dict_diff(meta, headers):
logging.info(_('... metadata has changed'))
headers, body = client.add_image_meta(meta)
_check_upload_response_headers(headers, body)
else:
if not os.path.exists(os.path.join(path, image_uuid + '.img')):
logging.info(_('... dump is missing image data, skipping'))
continue
# Upload the image itself
with open(os.path.join(path, image_uuid + '.img')) as img_file:
try:
headers, body = client.add_image(meta, img_file)
_check_upload_response_headers(headers, body)
except ImageAlreadyPresentException:
logging.error(IMAGE_ALREADY_PRESENT_MESSAGE
% image_uuid)
def replication_livecopy(options, args):
"""%(prog)s livecopy <fromserver:port> <toserver:port>
Load the contents of one glance instance into another.
fromserver:port: the location of the master glance instance.
toserver:port: the location of the slave glance instance.
"""
slave_server_port = args.pop()
slave_server, slave_port = slave_server_port.split(':')
slave_conn = httplib.HTTPConnection(slave_server, slave_port)
slave_client = ImageService(slave_conn, options.slavetoken)
master_server_port = args.pop()
master_server, master_port = master_server_port.split(':')
master_conn = httplib.HTTPConnection(master_server, master_port)
master_client = ImageService(master_conn, options.mastertoken)
for image in master_client.get_images():
logging.info(_('Considering %(id)s') % {'id': image['id']})
for key in options.dontreplicate.split(' '):
if key in image:
logging.debug(_('Stripping %(header)s from master metadata'),
{'header': key})
del image[key]
if _image_present(slave_client, image['id']):
# NOTE(mikal): Perhaps we just need to update the metadata?
# Note that we don't attempt to change an image file once it
# has been uploaded.
headers = slave_client.get_image_meta(image['id'])
if headers['status'] == 'active':
for key in options.dontreplicate.split(' '):
if key in image:
logging.debug(_('Stripping %(header)s from master '
'metadata'), {'header': key})
del image[key]
if key in headers:
logging.debug(_('Stripping %(header)s from slave '
'metadata'), {'header': key})
del headers[key]
if _dict_diff(image, headers):
logging.info(_('... metadata has changed'))
headers, body = slave_client.add_image_meta(image)
_check_upload_response_headers(headers, body)
elif image['status'] == 'active':
logging.info(_('%s is being synced') % image['id'])
if not options.metaonly:
image_response = master_client.get_image(image['id'])
try:
headers, body = slave_client.add_image(image,
image_response)
_check_upload_response_headers(headers, body)
except ImageAlreadyPresentException:
logging.error(IMAGE_ALREADY_PRESENT_MESSAGE % image['id'])
def replication_compare(options, args):
"""%(prog)s compare <fromserver:port> <toserver:port>
Compare the contents of fromserver with those of toserver.
fromserver:port: the location of the master glance instance.
toserver:port: the location of the slave glance instance.
"""
slave_server_port = args.pop()
slave_server, slave_port = slave_server_port.split(':')
slave_conn = httplib.HTTPConnection(slave_server, slave_port)
slave_client = ImageService(slave_conn, options.slavetoken)
master_server_port = args.pop()
master_server, master_port = master_server_port.split(':')
master_conn = httplib.HTTPConnection(master_server, master_port)
master_client = ImageService(master_conn, options.mastertoken)
for image in master_client.get_images():
if _image_present(slave_client, image['id']):
headers = slave_client.get_image_meta(image['id'])
for key in options.dontreplicate.split(' '):
if key in image:
logging.debug(_('Stripping %(header)s from master '
'metadata'), {'header': key})
del image[key]
if key in headers:
logging.debug(_('Stripping %(header)s from slave '
'metadata'), {'header': key})
del headers[key]
for key in image:
if image[key] != headers.get(key, None):
logging.info(_('%(image_id)s: field %(key)s differs '
'(source is %(master_value)s, destination '
'is %(slave_value)s)')
% {'image_id': image['id'],
'key': key,
'master_value': image[key],
'slave_value': headers.get(key,
'undefined')})
else:
logging.debug(_('%(image_id)s is identical')
% {'image_id': image['id']})
elif image['status'] == 'active':
logging.info(_('%s: entirely missing from the destination')
% image['id'])
def _check_upload_response_headers(headers, body):
"""Check that the headers of an upload are reasonable.
headers: the headers from the upload
body: the body from the upload
"""
if 'status' not in headers:
try:
d = json.loads(body)
if 'image' in d and 'status' in d['image']:
return
except:
raise UploadException('Image upload problem: %s' % body)
def _image_present(client, image_uuid):
"""Check if an image is present in glance.
client: the ImageService
image_uuid: the image uuid to check
Returns: True if the image is present
"""
headers = client.get_image_meta(image_uuid)
return 'status' in headers
def parse_options(parser, cli_args):
"""Returns the parsed CLI options, command to run and its arguments, merged
with any same-named options found in a configuration file
parser: the option parser
cli_args: the arguments passed on the command line
Returns: a tuple of (the parsed options, the command, the command name)
"""
if not cli_args:
cli_args.append('-h') # Show options in usage output...
(options, args) = parser.parse_args(cli_args)
# HACK(sirp): Make the parser available to the print_help method
# print_help is a command, so it only accepts (options, args); we could
# one-off have it take (parser, options, args), however, for now, I think
# this little hack will suffice
options.__parser = parser
if not args:
parser.print_usage()
sys.exit(0)
command_name = args.pop(0)
command = lookup_command(parser, command_name)
return (options, command, args)
def print_help(options, args):
"""Print help specific to a command.
options: the parsed command line options
args: the command line
"""
if len(args) != 1:
print COMMANDS
sys.exit(1)
parser = options.__parser
command_name = args.pop()
command = lookup_command(parser, command_name)
print command.__doc__ % {'prog': os.path.basename(sys.argv[0])}
def lookup_command(parser, command_name):
"""Lookup a command.
parser: the command parser
command_name: the command name
Returns: a method which implements that command
"""
BASE_COMMANDS = {'help': print_help}
REPLICATION_COMMANDS = {
'compare': replication_compare,
'dump': replication_dump,
'livecopy': replication_livecopy,
'load': replication_load,
'size': replication_size,
}
commands = {}
for command_set in (BASE_COMMANDS, REPLICATION_COMMANDS):
commands.update(command_set)
try:
command = commands[command_name]
except KeyError:
parser.print_usage()
sys.exit(_("Unknown command: %s") % command_name)
return command
if __name__ == '__main__':
usage = """
%%prog <command> [options] [args]
%s
""" % COMMANDS
oparser = optparse.OptionParser(version='%%prog',
usage=usage.strip())
# Options
oparser.add_option('-c', '--chunksize', action="store", default=65536,
help="Amount of data to transfer per HTTP write")
oparser.add_option('-d', '--debug', action="store_true", default=False,
help="Print debugging information")
oparser.add_option('-D', '--dontreplicate', action="store",
default=('created_at date deleted_at location '
'updated_at'),
help="List of fields to not replicate")
oparser.add_option('-m', '--metaonly', action="store_true", default=False,
help="Only replicate metadata, not images")
oparser.add_option('-l', '--logfile', action="store", default='',
help="Path of file to log to")
oparser.add_option('-s', '--syslog', action="store_true", default=False,
help="Log to syslog instead of a file")
oparser.add_option('-t', '--token', action="store", default='',
help=("Pass in your authentication token if you have "
"one. If you use this option the same token is "
"used for both the master and the slave."))
oparser.add_option('-M', '--mastertoken', action="store", default='',
help=("Pass in your authentication token if you have "
"one. This is the token used for the master."))
oparser.add_option('-S', '--slavetoken', action="store", default='',
help=("Pass in your authentication token if you have "
"one. This is the token used for the slave."))
oparser.add_option('-v', '--verbose', action="store_true", default=False,
help="Print more verbose output")
(options, command, args) = parse_options(oparser, sys.argv[1:])
# Setup logging
root_logger = logging.root
if options.debug:
root_logger.setLevel(logging.DEBUG)
elif options.verbose:
root_logger.setLevel(logging.INFO)
else:
root_logger.setLevel(logging.WARNING)
formatter = logging.Formatter()
if options.syslog:
handler = logging.handlers.SysLogHandler(address='/dev/log')
elif options.logfile:
handler = logging.handlers.WatchedFileHandler(options.logfile)
else:
handler = logging.StreamHandler(sys.stdout)
if options.token:
options.slavetoken = options.token
options.mastertoken = options.token
handler.setFormatter(formatter)
root_logger.addHandler(handler)
command(options, args)