# Copyright 2010 OpenStack Foundation
# Copyright 2013 Hewlett-Packard Development Company, L.P.
# 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 abc
import datetime
import os
import shutil
from oslo_log import log
from oslo_utils import uuidutils
import requests
import sendfile
import six
from six.moves import http_client
import six.moves.urllib.parse as urlparse
from ironic.common import exception
from ironic.common.glance_service import image_service
from ironic.common.i18n import _
from ironic.common import utils
IMAGE_CHUNK_SIZE = 1024 * 1024 # 1mb
# NOTE(kaifeng) Image will be truncated to 2GiB by sendfile,
# we use a large chunk size here for a better performance
# while keep the chunk size less than the size limit.
SENDFILE_CHUNK_SIZE = 1024 * 1024 * 1024 # 1Gb
LOG = log.getLogger(__name__)
# TODO(dtantsur): temporary re-import, refactor the code and remove it.
GlanceImageService = image_service.GlanceImageService
[docs]@six.add_metaclass(abc.ABCMeta)
class BaseImageService(object):
"""Provides retrieval of disk images."""
[docs] @abc.abstractmethod
def validate_href(self, image_href):
"""Validate image reference.
:param image_href: Image reference.
:raises: exception.ImageRefValidationFailed.
:returns: Information needed to further operate with an image.
"""
[docs] @abc.abstractmethod
def download(self, image_href, image_file):
"""Downloads image to specified location.
:param image_href: Image reference.
:param image_file: File object to write data to.
:raises: exception.ImageRefValidationFailed.
:raises: exception.ImageDownloadFailed.
"""
[docs] @abc.abstractmethod
def show(self, image_href):
"""Get dictionary of image properties.
:param image_href: Image reference.
:raises: exception.ImageRefValidationFailed.
:returns: dictionary of image properties. It has three of them: 'size',
'updated_at' and 'properties'. 'updated_at' attribute is a naive
UTC datetime object.
"""
[docs]class HttpImageService(BaseImageService):
"""Provides retrieval of disk images using HTTP."""
[docs] def validate_href(self, image_href, secret=False):
"""Validate HTTP image reference.
:param image_href: Image reference.
:param secret: Specify if image_href being validated should not be
shown in exception message.
:raises: exception.ImageRefValidationFailed if HEAD request failed or
returned response code not equal to 200.
:returns: Response to HEAD request.
"""
output_url = 'secreturl' if secret else image_href
try:
response = requests.head(image_href)
if response.status_code != http_client.OK:
raise exception.ImageRefValidationFailed(
image_href=output_url,
reason=_("Got HTTP code %s instead of 200 in response to "
"HEAD request.") % response.status_code)
except requests.RequestException as e:
raise exception.ImageRefValidationFailed(image_href=output_url,
reason=six.text_type(e))
return response
[docs] def download(self, image_href, image_file):
"""Downloads image to specified location.
:param image_href: Image reference.
:param image_file: File object to write data to.
:raises: exception.ImageRefValidationFailed if GET request returned
response code not equal to 200.
:raises: exception.ImageDownloadFailed if:
* IOError happened during file write;
* GET request failed.
"""
try:
response = requests.get(image_href, stream=True)
if response.status_code != http_client.OK:
raise exception.ImageRefValidationFailed(
image_href=image_href,
reason=_("Got HTTP code %s instead of 200 in response to "
"GET request.") % response.status_code)
with response.raw as input_img:
shutil.copyfileobj(input_img, image_file, IMAGE_CHUNK_SIZE)
except (requests.RequestException, IOError) as e:
raise exception.ImageDownloadFailed(image_href=image_href,
reason=six.text_type(e))
[docs] def show(self, image_href):
"""Get dictionary of image properties.
:param image_href: Image reference.
:raises: exception.ImageRefValidationFailed if:
* HEAD request failed;
* HEAD request returned response code not equal to 200;
* Content-Length header not found in response to HEAD request.
:returns: dictionary of image properties. It has three of them: 'size',
'updated_at' and 'properties'. 'updated_at' attribute is a naive
UTC datetime object.
"""
response = self.validate_href(image_href)
image_size = response.headers.get('Content-Length')
if image_size is None:
raise exception.ImageRefValidationFailed(
image_href=image_href,
reason=_("Cannot determine image size as there is no "
"Content-Length header specified in response "
"to HEAD request."))
# Parse last-modified header to return naive datetime object
str_date = response.headers.get('Last-Modified')
date = None
if str_date:
http_date_format_strings = [
'%a, %d %b %Y %H:%M:%S GMT', # RFC 822
'%A, %d-%b-%y %H:%M:%S GMT', # RFC 850
'%a %b %d %H:%M:%S %Y' # ANSI C
]
for fmt in http_date_format_strings:
try:
date = datetime.datetime.strptime(str_date, fmt)
break
except ValueError:
continue
return {
'size': int(image_size),
'updated_at': date,
'properties': {}
}
[docs]class FileImageService(BaseImageService):
"""Provides retrieval of disk images available locally on the conductor."""
[docs] def validate_href(self, image_href):
"""Validate local image reference.
:param image_href: Image reference.
:raises: exception.ImageRefValidationFailed if source image file
doesn't exist.
:returns: Path to image file if it exists.
"""
image_path = urlparse.urlparse(image_href).path
if not os.path.isfile(image_path):
raise exception.ImageRefValidationFailed(
image_href=image_href,
reason=_("Specified image file not found."))
return image_path
[docs] def download(self, image_href, image_file):
"""Downloads image to specified location.
:param image_href: Image reference.
:param image_file: File object to write data to.
:raises: exception.ImageRefValidationFailed if source image file
doesn't exist.
:raises: exception.ImageDownloadFailed if exceptions were raised while
writing to file or creating hard link.
"""
source_image_path = self.validate_href(image_href)
dest_image_path = image_file.name
local_device = os.stat(dest_image_path).st_dev
try:
# We should have read and write access to source file to create
# hard link to it.
if (local_device == os.stat(source_image_path).st_dev
and os.access(source_image_path, os.R_OK | os.W_OK)):
image_file.close()
os.remove(dest_image_path)
os.link(source_image_path, dest_image_path)
else:
filesize = os.path.getsize(source_image_path)
offset = 0
with open(source_image_path, 'rb') as input_img:
while offset < filesize:
# TODO(kaifeng) Use os.sendfile() and remove sendfile
# dependency when python2 support is dropped.
count = min(SENDFILE_CHUNK_SIZE, filesize - offset)
nbytes_out = sendfile.sendfile(image_file.fileno(),
input_img.fileno(),
offset,
count)
offset += nbytes_out
except Exception as e:
raise exception.ImageDownloadFailed(image_href=image_href,
reason=six.text_type(e))
[docs] def show(self, image_href):
"""Get dictionary of image properties.
:param image_href: Image reference.
:raises: exception.ImageRefValidationFailed if image file specified
doesn't exist.
:returns: dictionary of image properties. It has three of them: 'size',
'updated_at' and 'properties'. 'updated_at' attribute is a naive
UTC datetime object.
"""
source_image_path = self.validate_href(image_href)
return {
'size': os.path.getsize(source_image_path),
'updated_at': utils.unix_file_modification_datetime(
source_image_path),
'properties': {}
}
protocol_mapping = {
'http': HttpImageService,
'https': HttpImageService,
'file': FileImageService,
'glance': GlanceImageService,
}
[docs]def get_image_service(image_href, client=None, context=None):
"""Get image service instance to download the image.
:param image_href: String containing href to get image service for.
:param client: Glance client to be used for download, used only if
image_href is Glance href.
:param context: request context, used only if image_href is Glance href.
:raises: exception.ImageRefValidationFailed if no image service can
handle specified href.
:returns: Instance of an image service class that is able to download
specified image.
"""
scheme = urlparse.urlparse(image_href).scheme.lower()
if not scheme:
if uuidutils.is_uuid_like(six.text_type(image_href)):
cls = GlanceImageService
else:
raise exception.ImageRefValidationFailed(
image_href=image_href,
reason=_('Scheme-less image href is not a UUID.'))
else:
cls = protocol_mapping.get(scheme)
if not cls:
raise exception.ImageRefValidationFailed(
image_href=image_href,
reason=_('Image download protocol %s is not supported.'
) % scheme)
if cls == GlanceImageService:
return cls(client, context)
return cls()
