diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/virtBootstrap/sources/docker_source.py | 10 | ||||
| -rw-r--r-- | src/virtBootstrap/sources/file_source.py | 14 | ||||
| -rw-r--r-- | src/virtBootstrap/utils.py | 146 |
3 files changed, 102 insertions, 68 deletions
diff --git a/src/virtBootstrap/sources/docker_source.py b/src/virtBootstrap/sources/docker_source.py index 2dadb42..a6ea3e6 100644 --- a/src/virtBootstrap/sources/docker_source.py +++ b/src/virtBootstrap/sources/docker_source.py @@ -272,7 +272,15 @@ class DockerSource(object): elif self.output_format == 'qcow2': self.progress("Extracting container layers into qcow2 images", value=50, logger=logger) - utils.extract_layers_in_qcow2(self.layers, dest, self.progress) + + img = utils.BuildImage( + layers=self.layers, + dest=dest, + progress=self.progress + ) + img.create_base_layer() + img.create_backing_chains() + else: raise Exception("Unknown format:" + self.output_format) diff --git a/src/virtBootstrap/sources/file_source.py b/src/virtBootstrap/sources/file_source.py index 412db8a..69f024c 100644 --- a/src/virtBootstrap/sources/file_source.py +++ b/src/virtBootstrap/sources/file_source.py @@ -64,14 +64,16 @@ class FileSource(object): utils.untar_layers(layer, dest, self.progress) elif self.output_format == 'qcow2': - # Remove the old path - file_name = os.path.basename(self.path) - qcow2_file = os.path.realpath('{}/{}.qcow2'.format(dest, - file_name)) - self.progress("Extracting files into qcow2 image", value=0, logger=logger) - utils.create_qcow2(self.path, qcow2_file) + + img = utils.BuildImage( + layers=layer, + dest=dest, + progress=self.progress + ) + img.create_base_layer() + else: raise Exception("Unknown format:" + self.output_format) diff --git a/src/virtBootstrap/utils.py b/src/virtBootstrap/utils.py index be9133c..5fb5d8c 100644 --- a/src/virtBootstrap/utils.py +++ b/src/virtBootstrap/utils.py @@ -33,6 +33,7 @@ import tempfile import logging import re +import guestfs import passlib.hosts # pylint: disable=invalid-name @@ -42,6 +43,8 @@ logger = logging.getLogger(__name__) DEFAULT_OUTPUT_FORMAT = 'dir' # Default virtual size of qcow2 image DEF_QCOW2_SIZE = '5G' +DEF_BASE_IMAGE_SIZE = 5 * 1024 * 1024 * 1024 + if os.geteuid() == 0: LIBVIRT_CONN = "lxc:///" DEFAULT_IMG_DIR = "/var/lib/virt-bootstrap/docker_images" @@ -51,6 +54,88 @@ else: DEFAULT_IMG_DIR += "/.local/share/virt-bootstrap/docker_images" +class BuildImage(object): + """ + Use guestfs-python to create qcow2 disk images. + """ + + def __init__(self, layers, dest, progress): + """ + @param tar_files: Tarballs to be converted to qcow2 images + @param dest: Directory where the qcow2 images will be created + @param progress: Instance of the progress module + """ + self.g = guestfs.GuestFS(python_return_dict=True) + self.layers = layers + self.nlayers = len(layers) + self.dest = dest + self.progress = progress + self.qcow2_files = [] + + def create_base_layer(self, fmt='qcow2', size=DEF_BASE_IMAGE_SIZE): + """ + Create and format qcow2 disk image which represnts the base layer. + """ + self.qcow2_files = [os.path.join(self.dest, 'layer-0.qcow2')] + self.progress("Creating base layer", logger=logger) + self.g.disk_create(self.qcow2_files[0], fmt, size) + self.g.add_drive(self.qcow2_files[0], format=fmt) + self.g.launch() + self.progress("Formating disk image", logger=logger) + self.g.mkfs("ext3", '/dev/sda') + self.extract_layer(0, '/dev/sda') + # Shutdown qemu instance to avoid hot-plugging of devices. + self.g.shutdown() + + def create_backing_chains(self): + """ + Convert other layers to qcow2 images linked as backing chains. + """ + for i in range(1, self.nlayers): + self.qcow2_files.append( + os.path.join(self.dest, 'layer-%d.qcow2' % i) + ) + self.progress( + "Creating image (%d/%d)" % (i + 1, self.nlayers), + logger=logger + ) + self.g.disk_create( + filename=self.qcow2_files[i], + format='qcow2', + size=-1, + backingfile=self.qcow2_files[i - 1], + backingformat='qcow2' + ) + self.g.add_drive(self.qcow2_files[i], format='qcow2') + self.g.launch() + devices = self.g.list_devices() + # Tar-in layers (skip the base layer) + for index in range(1, self.nlayers): + self.extract_layer(index, devices[index - 1]) + self.g.shutdown() + + def extract_layer(self, index, dev): + """ + Extract tarball of layer to device + """ + tar_file, tar_size = self.layers[index] + log_layer_extract( + tar_file, tar_size, index + 1, self.nlayers, self.progress + ) + self.tar_in(dev, tar_file) + + def tar_in(self, dev, tar_file): + """ + Common pattern used to tar-in archive into image + """ + self.g.mount(dev, '/') + # Restore extended attributes, SELinux contexts and POSIX ACLs + # from tar file. + self.g.tar_in(tar_file, '/', get_compression_type(tar_file), + xattrs=True, selinux=True, acls=True) + self.g.umount('/') + + def get_compression_type(tar_file): """ Get compression type of tar file. @@ -212,67 +297,6 @@ def get_mime_type(path): return output.read().decode('utf-8').split()[1] -def create_qcow2(tar_file, layer_file, backing_file=None, size=DEF_QCOW2_SIZE): - """ - Create qcow2 image from tarball. - """ - qemu_img_cmd = ["qemu-img", "create", "-f", "qcow2", layer_file, size] - - if not backing_file: - logger.info("Creating base qcow2 image") - execute(qemu_img_cmd) - - logger.info("Formatting qcow2 image") - execute(['virt-format', - '--format=qcow2', - '--partition=none', - '--filesystem=ext3', - '-a', layer_file]) - else: - # Add backing chain - qemu_img_cmd.insert(2, "-b") - qemu_img_cmd.insert(3, backing_file) - - logger.info("Creating qcow2 image with backing chain") - execute(qemu_img_cmd) - - # Extract tarball using "tar-in" command from libguestfs - tar_in_cmd = ["guestfish", - "-a", layer_file, - '-m', '/dev/sda', - 'tar-in', tar_file, "/"] - - # Check if tarball is compressed - compression = get_compression_type(tar_file) - if compression is not None: - tar_in_cmd.append('compress:' + compression) - - # Execute virt-tar-in command - execute(tar_in_cmd) - - -def extract_layers_in_qcow2(layers_list, dest_dir, progress): - """ - Extract docker layers in qcow2 images with backing chains. - """ - qcow2_backing_file = None - - nlayers = len(layers_list) - for index, layer in enumerate(layers_list): - tar_file, tar_size = layer - log_layer_extract(tar_file, tar_size, index + 1, nlayers, progress) - - # Name format for the qcow2 image - qcow2_layer_file = "{}/layer-{}.qcow2".format(dest_dir, index) - # Create the image layer - create_qcow2(tar_file, qcow2_layer_file, qcow2_backing_file) - # Keep the file path for the next layer - qcow2_backing_file = qcow2_layer_file - - # Update progress value - progress(value=(float(index + 1) / nlayers * 50) + 50) - - def get_image_dir(no_cache=False): """ Get the directory where image layers are stored. |