diff options
Diffstat (limited to 'src/virtBootstrap/sources.py')
| -rw-r--r-- | src/virtBootstrap/sources.py | 93 |
1 files changed, 59 insertions, 34 deletions
diff --git a/src/virtBootstrap/sources.py b/src/virtBootstrap/sources.py index a1f8544..87278d2 100644 --- a/src/virtBootstrap/sources.py +++ b/src/virtBootstrap/sources.py @@ -15,6 +15,11 @@ # You should have received a copy of the GNU General Public License # along with this program. If not, see <http://www.gnu.org/licenses/>. +""" +Class definitions which process container image or +archive from source and unpack them in destination directory. +""" + import hashlib import json import shutil @@ -26,22 +31,24 @@ from subprocess import call, CalledProcessError, PIPE, Popen # Default virtual size of qcow2 image DEF_QCOW2_SIZE = '5G' -# default_image_dir - Path where Docker images (tarballs) will be stored if os.geteuid() == 0: - virt_sandbox_connection = "lxc:///" - default_image_dir = "/var/lib/virt-bootstrap/docker_images" + LIBVIRT_CONN = "lxc:///" + DEFAULT_IMG_DIR = "/var/lib/virt-bootstrap/docker_images" else: - virt_sandbox_connection = "qemu:///session" - default_image_dir = \ - os.environ['HOME'] + "/.local/share/virt-bootstrap/docker_images" + LIBVIRT_CONN = "qemu:///session" + DEFAULT_IMG_DIR = os.environ['HOME'] + DEFAULT_IMG_DIR += "/.local/share/virt-bootstrap/docker_images" def checksum(path, sum_type, sum_expected): + """ + Validate file using checksum. + """ algorithm = getattr(hashlib, sum_type) try: - fd = open(path, 'rb') - content = fd.read() - fd.close() + handle = open(path, 'rb') + content = handle.read() + handle.close() actual = algorithm(content).hexdigest() return actual == sum_expected @@ -50,9 +57,11 @@ def checksum(path, sum_type, sum_expected): def safe_untar(src, dest): - # Extract tarball in LXC container for safety + """ + Extract tarball within LXC container for safety. + """ virt_sandbox = ['virt-sandbox', - '-c', virt_sandbox_connection, + '-c', LIBVIRT_CONN, '-m', 'host-bind:/mnt=' + dest] # Bind destination folder # Compression type is auto detected from tar @@ -64,16 +73,22 @@ def safe_untar(src, dest): def get_layer_info(digest, image_dir): + """ + Get checksum type/value and path to corresponding tarball. + """ sum_type, sum_value = digest.split(':') layer_file = "{}/{}.tar".format(image_dir, sum_value) return (sum_type, sum_value, layer_file) def untar_layers(layers_list, image_dir, dest_dir): + """ + Untar each of layers from container image. + """ for layer in layers_list: sum_type, sum_value, layer_file = get_layer_info(layer['digest'], image_dir) - logging.info('Untar layer file: ({}) {}'.format(sum_type, layer_file)) + logging.info('Untar layer file: (%s) %s', sum_type, layer_file) # Verify the checksum if not checksum(layer_file, sum_type, sum_value): @@ -139,6 +154,9 @@ def create_qcow2(tar_file, layer_file, backing_file=None, size=DEF_QCOW2_SIZE): def extract_layers_in_qcow2(layers_list, image_dir, dest_dir): + """ + Extract docker layers in qcow2 images with backing chains. + """ qcow2_backing_file = None for index, layer in enumerate(layers_list): @@ -146,7 +164,7 @@ def extract_layers_in_qcow2(layers_list, image_dir, dest_dir): sum_type, sum_value, tar_file = \ get_layer_info(layer['digest'], image_dir) - logging.info('Untar layer file: ({}) {}'.format(sum_type, tar_file)) + logging.info('Untar layer file: (%s) %s', sum_type, tar_file) # Verify the checksum if not checksum(tar_file, sum_type, sum_value): @@ -160,17 +178,20 @@ def extract_layers_in_qcow2(layers_list, image_dir, dest_dir): qcow2_backing_file = qcow2_layer_file -class FileSource: - def __init__(self, url, username, password, fmt, insecure, no_cache): +class FileSource(object): + """ + Extract root filesystem from file. + """ + def __init__(self, url, args): self.path = url.path - self.output_format = fmt + self.output_format = args.format def unpack(self, dest): - ''' + """ Safely extract root filesystem from tarball @param dest: Directory path where the files to be extraced - ''' + """ if self.output_format == 'dir': logging.info("Extracting files into destination directory") safe_untar(self.path, dest) @@ -190,9 +211,13 @@ class FileSource: logging.info("Files are stored in: " + dest) -class DockerSource: - def __init__(self, url, username, password, fmt, insecure, no_cache): - ''' +class DockerSource(object): + """ + Extract files from Docker image + """ + + def __init__(self, url, args): + """ Bootstrap root filesystem from Docker registry @param url: Address of source registry @@ -201,33 +226,33 @@ class DockerSource: @param fmt: Format used to store image [dir, qcow2] @param insecure: Do not require HTTPS and certificate verification @param no_cache: Whether to store downloaded images or not - ''' + """ self.registry = url.netloc self.image = url.path - self.username = username - self.password = password - self.output_format = fmt - self.insecure = insecure - self.no_cache = no_cache + self.username = args.username + self.password = args.password + self.output_format = args.format + self.insecure = args.not_secure + self.no_cache = args.no_cache if self.image and not self.image.startswith('/'): self.image = '/' + self.image self.url = "docker://" + self.registry + self.image def unpack(self, dest): - ''' + """ Extract image files from Docker image @param dest: Directory path where the files to be extraced - ''' + """ if self.no_cache: tmp_dest = tempfile.mkdtemp('virt-bootstrap') images_dir = tmp_dest else: - if not os.path.exists(default_image_dir): - os.makedirs(default_image_dir) - images_dir = default_image_dir + if not os.path.exists(DEFAULT_IMG_DIR): + os.makedirs(DEFAULT_IMG_DIR) + images_dir = DEFAULT_IMG_DIR try: # Run skopeo copy into a tmp folder @@ -247,8 +272,8 @@ class DockerSource: check_call(skopeo_copy) # Get the layers list from the manifest - mf = open(images_dir+"/manifest.json", "r") - manifest = json.load(mf) + manifest_file = open(images_dir+"/manifest.json", "r") + manifest = json.load(manifest_file) # Layers are in order - root layer first # Reference: |