3:11 p.m.
From: Daniel P Berrange <berrange(a)redhat.com>
virt-sandbox-image.py is a python script that lets you download Docker
images easily. It is a proof of concept code and consumes Docker Rest API.
---
po/POTFILES.in | 1 +
virt-sandbox-image/virt-sandbox-image.py | 394 +++++++++++++++++++++++++++++++
2 files changed, 395 insertions(+)
create mode 100644 virt-sandbox-image/virt-sandbox-image.py
diff --git a/po/POTFILES.in b/po/POTFILES.in
index afcb050..7204112 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -11,3 +11,4 @@ libvirt-sandbox/libvirt-sandbox-context-interactive.c
libvirt-sandbox/libvirt-sandbox-init-common.c
libvirt-sandbox/libvirt-sandbox-rpcpacket.c
libvirt-sandbox/libvirt-sandbox-util.c
+virt-sandbox-image/virt-sandbox-image.py
diff --git a/virt-sandbox-image/virt-sandbox-image.py
b/virt-sandbox-image/virt-sandbox-image.py
new file mode 100644
index 0000000..4f5443b
--- /dev/null
+++ b/virt-sandbox-image/virt-sandbox-image.py
@@ -0,0 +1,394 @@
+#!/usr/bin/python -Es
+#
+# Authors: Daniel P. Berrange <berrange(a)redhat.com>
+#
+# Copyright (C) 2013 Red Hat, Inc.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+#
+
+import argparse
+import gettext
+import hashlib
+import json
+import os
+import os.path
+import shutil
+import sys
+import urllib2
+import subprocess
+
+default_index_server = "index.docker.io"
+default_template_dir = "/var/lib/libvirt/templates"
+
+debug = True
+verbose = True
+
+gettext.bindtextdomain("libvirt-sandbox", "/usr/share/locale")
+gettext.textdomain("libvirt-sandbox")
+try:
+ gettext.install("libvirt-sandbox",
+ localedir="/usr/share/locale",
+ unicode=False,
+ codeset = 'utf-8')
+except IOError:
+ import __builtin__
+ __builtin__.__dict__['_'] = unicode
+
+
+def debug(msg):
+ sys.stderr.write(msg)
+
+def info(msg):
+ sys.stdout.write(msg)
+
+def get_url(server, path, headers):
+ url = "https://" + server + path
+ debug(" Fetching %s..." % url)
+ req = urllib2.Request(url=url)
+
+ if json:
+ req.add_header("Accept", "application/json")
+
+ for h in headers.keys():
+ req.add_header(h, headers[h])
+
+ return urllib2.urlopen(req)
+
+def get_json(server, path, headers):
+ try:
+ res = get_url(server, path, headers)
+ data = json.loads(res.read())
+ debug("OK\n")
+ return (data, res)
+ except Exception, e:
+ debug("FAIL %s\n" % str(e))
+ raise
+
+def save_data(server, path, headers, dest, checksum=None, datalen=None):
+ try:
+ res = get_url(server, path, headers)
+
+ csum = None
+ if checksum is not None:
+ csum = hashlib.sha256()
+
+ pattern = [".", "o", "O", "o"]
+ patternIndex = 0
+ donelen = 0
+
+ with open(dest, "w") as f:
+ while 1:
+ buf = res.read(1024*64)
+ if not buf:
+ break
+ if csum is not None:
+ csum.update(buf)
+ f.write(buf)
+
+ if datalen is not None:
+ donelen = donelen + len(buf)
+ debug("\x1b[s%s (%5d Kb of %5d Kb)\x1b8" % (
+ pattern[patternIndex], (donelen/1024), (datalen/1024)
+ ))
+ patternIndex = (patternIndex + 1) % 4
+
+ debug("\x1b[K")
+ if csum is not None:
+ csumstr = "sha256:" + csum.hexdigest()
+ if csumstr != checksum:
+ debug("FAIL checksum '%s' does not match '%s'"
% (csumstr, checksum))
+ os.remove(dest)
+ raise IOError("Checksum '%s' for data does not match
'%s'" % (csumstr, checksum))
+ debug("OK\n")
+ return res
+ except Exception, e:
+ debug("FAIL %s\n" % str(e))
+ raise
+
+
+def download_template(name, server, destdir):
+ tag = "latest"
+
+ offset = name.find(':')
+ if offset != -1:
+ tag = name[offset + 1:]
+ name = name[0:offset]
+
+ # First we must ask the index server about the image name. THe
+ # index server will return an auth token we can use when talking
+ # to the registry server. We need this token even when anonymous
+ try:
+ (data, res) = get_json(server, "/v1/repositories/" + name +
"/images",
+ {"X-Docker-Token": "true"})
+ except urllib2.HTTPError, e:
+ raise ValueError(["Image '%s' does not exist" % name])
+
+ registryserver = res.info().getheader('X-Docker-Endpoints')
+ token = res.info().getheader('X-Docker-Token')
+ checksums = {}
+ for layer in data:
+ pass
+ # XXX Checksums here don't appear to match the data in
+ # image download later. Find out what these are sums of
+ #checksums[layer["id"]] = layer["checksum"]
+
+ # Now we ask the registry server for the list of tags associated
+ # with the image. Tags usually reflect some kind of version of
+ # the image, but they aren't officially "versions". There is
+ # always a "latest" tag which is the most recent upload
+ #
+ # We must pass in the auth token from the index server. This
+ # token can only be used once, and we're given a cookie back
+ # in return to use for later RPC calls.
+ (data, res) = get_json(registryserver, "/v1/repositories/" + name +
"/tags",
+ { "Authorization": "Token " + token })
+
+ cookie = res.info().getheader('Set-Cookie')
+
+ if not tag in data:
+ raise ValueError(["Tag '%s' does not exist for image
'%s'" % (tag, name)])
+ imagetagid = data[tag]
+
+ # Only base images are self-contained, most images reference one
+ # or more parents, in a linear stack. Here we are getting the list
+ # of layers for the image with the tag we used.
+ (data, res) = get_json(registryserver, "/v1/images/" + imagetagid +
"/ancestry",
+ { "Cookie": cookie })
+
+ if data[0] != imagetagid:
+ raise ValueError(["Expected first layer id '%s' to match image id
'%s'",
+ data[0], imagetagid])
+
+ try:
+ createdFiles = []
+ createdDirs = []
+
+ for layerid in data:
+ templatedir = destdir + "/" + layerid
+ if not os.path.exists(templatedir):
+ os.mkdir(templatedir)
+ createdDirs.append(templatedir)
+
+ jsonfile = templatedir + "/template.json"
+ datafile = templatedir + "/template.tar.gz"
+
+ if not os.path.exists(jsonfile) or not os.path.exists(datafile):
+ # The '/json' URL gives us some metadata about the layer
+ res = save_data(registryserver, "/v1/images/" + layerid +
"/json",
+ { "Cookie": cookie }, jsonfile)
+ createdFiles.append(jsonfile)
+ layersize = int(res.info().getheader("x-docker-size"))
+
+ datacsum = None
+ if layerid in checksums:
+ datacsum = checksums[layerid]
+
+ # and the '/layer' URL is the actual payload, provided
+ # as a tar.gz archive
+ save_data(registryserver, "/v1/images/" + layerid +
"/layer",
+ { "Cookie": cookie }, datafile, datacsum, layersize)
+ createdFiles.append(datafile)
+
+ # Strangely the 'json' data for a layer doesn't include
+ # its actual name, so we save that in a json file of our own
+ index = {
+ "name": name,
+ }
+
+ indexfile = destdir + "/" + imagetagid + "/index.json"
+ with open(indexfile, "w") as f:
+ f.write(json.dumps(index))
+ except Exception, e:
+ for f in createdFiles:
+ try:
+ os.remove(f)
+ except:
+ pass
+ for d in createdDirs:
+ try:
+ os.rmdir(d)
+ except:
+ pass
+
+
+def delete_template(name, destdir):
+ imageusage = {}
+ imageparent = {}
+ imagenames = {}
+ imagedirs = os.listdir(destdir)
+ for imagetagid in imagedirs:
+ indexfile = destdir + "/" + imagetagid + "/index.json"
+ if os.path.exists(indexfile):
+ with open(indexfile, "r") as f:
+ index = json.load(f)
+ imagenames[index["name"]] = imagetagid
+ jsonfile = destdir + "/" + imagetagid + "/template.json"
+ if os.path.exists(jsonfile):
+ with open(jsonfile, "r") as f:
+ template = json.load(f)
+
+ parent = template.get("parent", None)
+ if parent:
+ if parent not in imageusage:
+ imageusage[parent] = []
+ imageusage[parent].append(imagetagid)
+ imageparent[imagetagid] = parent
+
+ if not name in imagenames:
+ raise ValueError(["Image %s does not exist locally" % name])
+
+ imagetagid = imagenames[name]
+ while imagetagid != None:
+ debug("Remove %s\n" % imagetagid)
+ parent = imageparent.get(imagetagid, None)
+
+ indexfile = destdir + "/" + imagetagid + "/index.json"
+ if os.path.exists(indexfile):
+ os.remove(indexfile)
+ jsonfile = destdir + "/" + imagetagid + "/template.json"
+ if os.path.exists(jsonfile):
+ os.remove(jsonfile)
+ datafile = destdir + "/" + imagetagid + "/template.tar.gz"
+ if os.path.exists(datafile):
+ os.remove(datafile)
+ imagedir = destdir + "/" + imagetagid
+ os.rmdir(imagedir)
+
+ if parent:
+ if len(imageusage[parent]) != 1:
+ debug("Parent %s is shared\n" % parent)
+ parent = None
+ imagetagid = parent
+
+
+def get_image_list(name, destdir):
+ imageparent = {}
+ imagenames = {}
+ imagedirs = os.listdir(destdir)
+ for imagetagid in imagedirs:
+ indexfile = destdir + "/" + imagetagid + "/index.json"
+ if os.path.exists(indexfile):
+ with open(indexfile, "r") as f:
+ index = json.load(f)
+ imagenames[index["name"]] = imagetagid
+ jsonfile = destdir + "/" + imagetagid + "/template.json"
+ if os.path.exists(jsonfile):
+ with open(jsonfile, "r") as f:
+ template = json.load(f)
+
+ parent = template.get("parent", None)
+ if parent:
+ imageparent[imagetagid] = parent
+
+ if not name in imagenames:
+ raise ValueError(["Image %s does not exist locally" % name])
+
+ imagetagid = imagenames[name]
+ imagelist = []
+ while imagetagid != None:
+ imagelist.append(imagetagid)
+ parent = imageparent.get(imagetagid, None)
+ imagetagid = parent
+
+ return imagelist
+
+def create_template(name, imagepath, format, destdir):
+ if not format in ["qcow2"]:
+ raise ValueError(["Unsupported image format %s" % format])
+
+ imagelist = get_image_list(name, destdir)
+ imagelist.reverse()
+
+ parentImage = None
+ for imagetagid in imagelist:
+ templateImage = destdir + "/" + imagetagid + "/template." +
format
+ cmd = ["qemu-img", "create", "-f",
"qcow2"]
+ if parentImage is not None:
+ cmd.append("-o")
+ cmd.append("backing_fmt=qcow2,backing_file=%s" % parentImage)
+ cmd.append(templateImage)
+ if parentImage is None:
+ cmd.append("10G")
+ debug("Run %s\n" % " ".join(cmd))
+ subprocess.call(cmd)
+ parentImage = templateImage
+
+def download(args):
+ info("Downloading %s from %s to %s\n" % (args.name, default_index_server,
default_template_dir))
+ download_template(args.name, default_index_server, default_template_dir)
+
+def delete(args):
+ info("Deleting %s from %s\n" % (args.name, default_template_dir))
+ delete_template(args.name, default_template_dir)
+
+def create(args):
+ info("Creating %s from %s in format %s\n" % (args.imagepath, args.name,
args.format))
+ create_template(args.name, args.imagepath, args.format, default_template_dir)
+
+def requires_name(parser):
+ parser.add_argument("name",
+ help=_("name of the template"))
+
+def gen_download_args(subparser):
+ parser = subparser.add_parser("download",
+ help=_("Download template data"))
+ requires_name(parser)
+ parser.set_defaults(func=download)
+
+def gen_delete_args(subparser):
+ parser = subparser.add_parser("delete",
+ help=_("Delete template data"))
+ requires_name(parser)
+ parser.set_defaults(func=delete)
+
+def gen_create_args(subparser):
+ parser = subparser.add_parser("create",
+ help=_("Create image from template data"))
+ requires_name(parser)
+ parser.add_argument("imagepath",
+ help=_("path for image"))
+ parser.add_argument("format",
+ help=_("format"))
+ parser.set_defaults(func=create)
+
+if __name__ == '__main__':
+ parser = argparse.ArgumentParser(description='Sandbox Container Image Tool')
+
+ subparser = parser.add_subparsers(help=_("commands"))
+ gen_download_args(subparser)
+ gen_delete_args(subparser)
+ gen_create_args(subparser)
+
+ try:
+ args = parser.parse_args()
+ args.func(args)
+ sys.exit(0)
+ except KeyboardInterrupt, e:
+ sys.exit(0)
+ except ValueError, e:
+ for line in e:
+ for l in line:
+ sys.stderr.write("%s: %s\n" % (sys.argv[0], l))
+ sys.stderr.flush()
+ sys.exit(1)
+ except IOError, e:
+ sys.stderr.write("%s: %s: %s\n" % (sys.argv[0], e.filename, e.reason))
+ sys.stderr.flush()
+ sys.exit(1)
+ except OSError, e:
+ sys.stderr.write("%s: %s\n" % (sys.argv[0], e))
+ sys.stderr.flush()
+ sys.exit(1)
--
2.1.0