When using this flag with format='dir' the overhead when extracting the
root file system of container image will be reduce by running `tar` on
the host instead of in sandbox.
---
src/virtBootstrap/sources/docker_source.py | 9 ++++++++-
src/virtBootstrap/sources/file_source.py | 4 +++-
src/virtBootstrap/utils.py | 29 ++++++++++++++++++-----------
src/virtBootstrap/virt_bootstrap.py | 6 ++++++
4 files changed, 35 insertions(+), 13 deletions(-)
diff --git a/src/virtBootstrap/sources/docker_source.py b/src/virtBootstrap/sources/docker_source.py
index d990b89..d979a14 100644
--- a/src/virtBootstrap/sources/docker_source.py
+++ b/src/virtBootstrap/sources/docker_source.py
@@ -51,6 +51,7 @@ class DockerSource(object):
@param password: Password to access source registry
@param fmt: Format used to store image [dir, qcow2]
@param not_secure: Do not require HTTPS and certificate verification
+ @param faster: Reduce the overhead when untar images to rootfs
@param no_cache: Whether to store downloaded images or not
@param progress: Instance of the progress module
"""
@@ -63,6 +64,7 @@ class DockerSource(object):
self.root_password = kwargs.get('root_password', None)
self.output_format = kwargs.get('fmt', utils.DEFAULT_OUTPUT_FORMAT)
self.insecure = kwargs.get('not_secure', False)
+ self.faster = kwargs.get('faster', False)
self.no_cache = kwargs.get('no_cache', False)
self.progress = kwargs['progress'].update_progress
self.images_dir = utils.get_image_dir(self.no_cache)
@@ -261,7 +263,12 @@ class DockerSource(object):
if self.output_format == 'dir':
self.progress("Extracting container layers", value=50,
logger=logger)
- utils.untar_layers(self.layers, dest, self.progress)
+ utils.untar_layers(
+ self.layers,
+ dest,
+ self.progress,
+ self.faster
+ )
elif self.output_format == 'qcow2':
self.progress("Extracting container layers into qcow2 images",
value=50, logger=logger)
diff --git a/src/virtBootstrap/sources/file_source.py b/src/virtBootstrap/sources/file_source.py
index 2a7617c..f80bb6b 100644
--- a/src/virtBootstrap/sources/file_source.py
+++ b/src/virtBootstrap/sources/file_source.py
@@ -40,6 +40,7 @@ class FileSource(object):
@param uri: Path to tar archive file.
@param fmt: Format used to store image [dir, qcow2]
+ @param faster: Reduce the overhead when untar images to rootfs
@param progress: Instance of the progress module
"""
self.path = kwargs['uri'].path
@@ -47,6 +48,7 @@ class FileSource(object):
self.uid_map = kwargs.get('uid_map', None)
self.gid_map = kwargs.get('gid_map', None)
self.root_password = kwargs.get('root_password', None)
+ self.faster = kwargs.get('faster', False)
self.progress = kwargs['progress'].update_progress
def unpack(self, dest):
@@ -62,7 +64,7 @@ class FileSource(object):
if self.output_format == 'dir':
self.progress("Extracting files into destination directory",
value=0, logger=logger)
- utils.safe_untar(self.path, dest)
+ utils.untar(self.path, dest, self.faster)
elif self.output_format == 'qcow2':
self.progress("Extracting files into qcow2 image", value=0,
logger=logger)
diff --git a/src/virtBootstrap/utils.py b/src/virtBootstrap/utils.py
index 578c776..3b7758f 100644
--- a/src/virtBootstrap/utils.py
+++ b/src/virtBootstrap/utils.py
@@ -289,18 +289,25 @@ def execute(cmd):
raise CalledProcessError(proc.returncode, cmd_str)
-def safe_untar(src, dest):
+def untar(src, dest, faster=False):
"""
- Extract tarball within LXC container for safety.
+ Extract tarball to destination path.
+
+ @param faster: If True reduce the overhead by running tar on the host
"""
- virt_sandbox = ['virt-sandbox',
- '-c', LIBVIRT_CONN,
- '-m', 'host-bind:/mnt=' + dest] # Bind destination folder
+ cmd = ['/bin/tar',
+ 'xf', src,
+ '-C', dest if faster else '/mnt',
+ '--exclude', 'dev/*']
- # Compression type is auto detected from tar
- # Exclude files under /dev to avoid "Cannot mknod: Operation not permitted"
- params = ['--', '/bin/tar', 'xf', src, '-C', '/mnt', '--exclude', 'dev/*']
- execute(virt_sandbox + params)
+ if not faster:
+ cmd = ['virt-sandbox',
+ # Set connection
+ '-c', LIBVIRT_CONN,
+ # Bind destination folder
+ '-m', 'host-bind:/mnt=' + dest,
+ '--'] + cmd
+ execute(cmd)
def bytes_to_size(number):
@@ -355,7 +362,7 @@ def get_mime_type(path):
.stdout.read().decode('utf-8').split()[1])
-def untar_layers(layers_list, dest_dir, progress):
+def untar_layers(layers_list, dest_dir, progress, faster=False):
"""
Untar each of layers from container image.
"""
@@ -365,7 +372,7 @@ def untar_layers(layers_list, dest_dir, progress):
layer_file = layer[2]
# Extract layer tarball into destination directory
- safe_untar(layer_file, dest_dir)
+ untar(layer_file, dest_dir, faster)
# Update progress value
progress(value=(float(index + 1) / nlayers * 50) + 50)
diff --git a/src/virtBootstrap/virt_bootstrap.py b/src/virtBootstrap/virt_bootstrap.py
index cbd9f0c..e465fb2 100755
--- a/src/virtBootstrap/virt_bootstrap.py
+++ b/src/virtBootstrap/virt_bootstrap.py
@@ -100,6 +100,7 @@ def bootstrap(uri, dest,
uid_map=None,
gid_map=None,
not_secure=False,
+ faster=None,
no_cache=False,
progress_cb=None):
"""
@@ -127,6 +128,7 @@ def bootstrap(uri, dest,
uid_map=uid_map,
gid_map=gid_map,
not_secure=not_secure,
+ faster=faster,
no_cache=no_cache,
root_password=root_password,
progress=prog).unpack(dest)
@@ -210,6 +212,9 @@ def main():
parser.add_argument("--status-only", action="store_const",
const=utils.write_progress,
help=_("Show only progress information"))
+ parser.add_argument("--faster", action="store_true",
+ help=_("Reduce the overhead when extracting layers "
+ "(use this option only for trusted images)"))
try:
args = parser.parse_args()
@@ -235,6 +240,7 @@ def main():
uid_map=uid_map,
gid_map=gid_map,
not_secure=args.not_secure,
+ faster=args.faster,
no_cache=args.no_cache,
progress_cb=args.status_only)
--
2.13.3
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