virt-manager/virtinst/install/urlfetcher.py
Cole Robinson f793986378 urlfetcher: Add xorriso ISOReader implementation
xorisso is the still maintained isoinfo alternative, and may be
the only iso reading tool in RHEL9, so we need to support it.
Make it the default for our spec file and test suite too

Signed-off-by: Cole Robinson <crobinso@redhat.com>
2021-05-22 14:56:10 -04:00

427 lines
12 KiB
Python

#
# Copyright 2006-2007, 2013 Red Hat, Inc.
#
# This work is licensed under the GNU GPLv2 or later.
# See the COPYING file in the top-level directory.
#
# Backends for the various URL types we support (http, https, ftp, local)
import ftplib
import io
import os
import subprocess
import tempfile
import urllib
import requests
from ..logger import log
#########################
# isoreader abstraction #
#########################
class _ISOReader:
def __init__(self, location):
self._location = location
def grabFile(self, url, scratchdir):
raise NotImplementedError()
def hasFile(self, url):
raise NotImplementedError()
class _ISOinfoReader(_ISOReader):
"""
Handle reading reading files off an iso
"""
def __init__(self, location):
super().__init__(location)
self._cache_file_list = self._make_file_list()
def _make_file_list(self):
cmd = ["isoinfo", "-J", "-i", self._location, "-f"]
log.debug("Generating iso filelist: %s", cmd)
output = subprocess.check_output(cmd, stderr=subprocess.DEVNULL)
return output.splitlines(False)
def grabFile(self, url, scratchdir):
ignore = scratchdir
cmd = ["isoinfo", "-J", "-i", self._location, "-x", url]
log.debug("Extracting iso file: %s", cmd)
return subprocess.check_output(cmd)
def hasFile(self, url):
return url.encode("ascii") in self._cache_file_list
class _XorrisoReader(_ISOReader):
def __init__(self, location):
super().__init__(location)
self._cache_file_list = self._make_file_list()
def _make_file_list(self):
delim = "VIRTINST_BEGINLIST"
cmd = ["xorriso", "-indev", self._location, "-print", delim, "-find"]
log.debug("Generating iso filelist: %s", cmd)
output = subprocess.check_output(cmd,
stderr=subprocess.DEVNULL, text=True)
return output.split(delim, 1)[1].strip().splitlines()
def grabFile(self, url, scratchdir):
tmp = tempfile.NamedTemporaryFile(
prefix="virtinst-iso", suffix="-" + os.path.basename(url),
dir=scratchdir)
cmd = ["xorriso", "-osirrox", "on", "-indev", self._location,
"-extract", url, tmp.name]
log.debug("Extracting iso file: %s", cmd)
subprocess.check_output(cmd)
return open(tmp.name, "rb").read()
def hasFile(self, url):
return ("'.%s'" % url) in self._cache_file_list
###########################
# Fetcher implementations #
###########################
class _URLFetcher(object):
"""
This is a generic base class for fetching/extracting files from
a media source, such as CD ISO, or HTTP/HTTPS/FTP server
"""
_block_size = 16384
_is_iso = False
def __init__(self, location, scratchdir, meter):
self.location = location
self.scratchdir = scratchdir
self.meter = meter
log.debug("Using scratchdir=%s", scratchdir)
self._prepare()
####################
# Internal helpers #
####################
def _make_full_url(self, filename):
"""
Generate a full fetchable URL from the passed filename, which
is relative to the self.location
"""
if not filename:
return self.location
return os.path.join(self.location, filename)
def _grabURL(self, filename, fileobj, fullurl=None):
"""
Download the filename from self.location, and write contents to
fileobj
"""
if fullurl:
url = fullurl
else:
url = self._make_full_url(filename)
try:
urlobj, size = self._grabber(url)
except Exception as e:
msg = (_("Couldn't acquire file %(url)s: %(error)s") % {
"url": url, "error": str(e)})
raise ValueError(msg) from None
log.debug("Fetching URI: %s", url)
self.meter.start(
text=_("Retrieving file %s...") % os.path.basename(filename),
size=size)
total = self._write(urlobj, fileobj)
self.meter.end(total)
def _write(self, urlobj, fileobj):
"""
Write the contents of urlobj to python file like object fileobj
"""
total = 0
while 1:
buff = urlobj.read(self._block_size)
if not buff:
break
fileobj.write(buff)
total += len(buff)
self.meter.update(total)
fileobj.flush()
return total
def _grabber(self, url):
"""
Returns the urlobj, size for the passed URL. urlobj is whatever
data needs to be passed to self._write
"""
raise NotImplementedError("must be implemented in subclass")
##############
# Public API #
##############
def is_iso(self):
"""
If this is a fetcher for local CDROM/ISO
"""
return self._is_iso
def _prepare(self):
"""
Perform any necessary setup
"""
def _cleanup(self):
"""
Perform any necessary cleanup
"""
def __del__(self):
self._cleanup()
def can_access(self):
"""
Return True if the location URL seems to be valid
"""
return True
def _hasFile(self, url):
raise NotImplementedError("Must be implemented in subclass")
def hasFile(self, filename):
"""
Return True if self.location has the passed filename
"""
url = self._make_full_url(filename)
ret = self._hasFile(url)
log.debug("hasFile(%s) returning %s", url, ret)
return ret
def acquireFile(self, filename, fullurl=None):
"""
Grab the passed filename from self.location and save it to
a temporary file, returning the temp filename
"""
# pylint: disable=redefined-variable-type
fn = None
try:
fileobj = tempfile.NamedTemporaryFile(
prefix="virtinst-", suffix="-" + os.path.basename(filename),
dir=self.scratchdir, delete=False)
fn = fileobj.name
self._grabURL(filename, fileobj, fullurl=fullurl)
log.debug("Saved file to %s", fn)
return fn
except BaseException: # pragma: no cover
if fn and os.path.exists(fn):
os.unlink(fn)
raise
def acquireFileContent(self, filename):
"""
Grab the passed filename from self.location and return it as a string
"""
fileobj = io.BytesIO()
self._grabURL(filename, fileobj)
return fileobj.getvalue().decode("utf-8")
class _HTTPURLFetcher(_URLFetcher):
_session = None
def _prepare(self):
self._session = requests.Session()
def _cleanup(self):
if self._session:
try:
self._session.close()
except Exception: # pragma: no cover
log.debug("Error closing requests.session", exc_info=True)
self._session = None
def can_access(self):
return self.hasFile("")
def _hasFile(self, url):
"""
We just do a HEAD request to see if the file exists
"""
try:
response = self._session.head(url, allow_redirects=True)
response.raise_for_status()
except Exception as e: # pragma: no cover
log.debug("HTTP hasFile request failed: %s", str(e))
return False
return True
def _grabber(self, url):
"""
Use requests for this
"""
response = self._session.get(url, stream=True)
response.raise_for_status()
try:
size = int(response.headers.get('content-length'))
except Exception: # pragma: no cover
size = None
return response, size
def _write(self, urlobj, fileobj):
"""
The requests object doesn't have a file-like read() option, so
we need to implement it ourselves
"""
total = 0
for data in urlobj.iter_content(chunk_size=self._block_size):
fileobj.write(data)
total += len(data)
self.meter.update(total)
fileobj.flush()
return total
class _FTPURLFetcher(_URLFetcher):
_ftp = None
def _prepare(self):
if self._ftp:
return # pragma: no cover
try:
parsed = urllib.parse.urlparse(self.location)
self._ftp = ftplib.FTP()
username = urllib.parse.unquote(parsed.username or '')
password = urllib.parse.unquote(parsed.password or '')
self._ftp.connect(parsed.hostname, parsed.port or 0)
self._ftp.login(username, password)
# Force binary mode
self._ftp.voidcmd("TYPE I")
except Exception as e: # pragma: no cover
msg = (_("Opening URL %(url)s failed: %(error)s") % {
"url": self.location, "error": str(e)})
raise ValueError(msg) from None
def _grabber(self, url):
"""
Use urllib and ftplib to grab the file
"""
request = urllib.request.Request(url)
urlobj = urllib.request.urlopen(request)
size = self._ftp.size(urllib.parse.urlparse(url)[2])
return urlobj, size
def _cleanup(self):
if not self._ftp:
return # pragma: no cover
try:
self._ftp.quit()
except Exception: # pragma: no cover
log.debug("Error quitting ftp connection", exc_info=True)
self._ftp = None
def _hasFile(self, url):
path = urllib.parse.urlparse(url)[2]
try:
try:
# If it's a file
self._ftp.size(path)
except ftplib.all_errors: # pragma: no cover
# If it's a dir
self._ftp.cwd(path)
except ftplib.all_errors as e: # pragma: no cover
log.debug("FTP hasFile: couldn't access %s: %s",
url, str(e))
return False
return True
class _LocalURLFetcher(_URLFetcher):
"""
For grabbing files from a local directory
"""
def _hasFile(self, url):
parsed = urllib.parse.urlparse(url)
return os.path.exists(parsed.path)
def _grabber(self, url):
parsed = urllib.parse.urlparse(url)
urlobj = open(parsed.path, "rb")
size = os.path.getsize(parsed.path)
return urlobj, size
class _ISOURLFetcher(_URLFetcher):
_isoreader = None
_is_iso = True
def _make_full_url(self, filename):
return os.path.join("/", filename)
def _get_isoreader(self):
if not self._isoreader:
self._isoreader = _XorrisoReader(self.location)
return self._isoreader
def _grabber(self, url):
if not self._hasFile(url):
raise RuntimeError("iso doesn't have file=%s" % url)
output = self._get_isoreader().grabFile(url, self.scratchdir)
return io.BytesIO(output), len(output)
def _hasFile(self, url):
return self._get_isoreader().hasFile(url)
class DirectFetcher(_URLFetcher):
def _make_full_url(self, filename):
return filename
def acquireFile(self, filename, fullurl=None):
if not fullurl:
fullurl = filename
filename = os.path.basename(filename)
fetcher = fetcherForURI(fullurl, self.scratchdir, self.meter, direct=True)
return fetcher.acquireFile(filename, fullurl) # pylint: disable=protected-access
def _hasFile(self, url):
return True
def _grabber(self, url):
raise RuntimeError( # pragma: no cover
"DirectFetcher shouldn't be used for file access.")
def fetcherForURI(uri, scratchdir, meter, direct=False):
if uri.startswith("http://") or uri.startswith("https://"):
fclass = _HTTPURLFetcher
elif uri.startswith("ftp://"):
fclass = _FTPURLFetcher
elif direct or os.path.isdir(uri):
# Pointing to a local tree
fclass = _LocalURLFetcher
else:
# Pointing to a path (e.g. iso), or a block device (e.g. /dev/cdrom)
fclass = _ISOURLFetcher
return fclass(uri, scratchdir, meter)