[virt-tools-list] [virt-bootstrap] [PATCH 1/1] docker-source: Get list of layers without `--raw`
Radostin Stoyanov
rstoyanov1 at gmail.com
Mon Dec 18 19:20:28 UTC 2017
When `skopeo inspect --raw docker://feodra` is used the returned
manifest content contains a list with manifests for specific
platforms [1] rather than a list with layers.
By using `skopeo inpect docker://fedora` the correct manifest
content is retrieved and a list with layers is provided. In addition,
skopeo handles the difference between schemaVersion 1 and 2.
[1] https://docs.docker.com/registry/spec/manifest-v2-2/#manifest-list-field-descriptions
---
src/virtBootstrap/sources/docker_source.py | 29 ++++++-------
tests/docker_source.py | 66 +++++-------------------------
2 files changed, 22 insertions(+), 73 deletions(-)
diff --git a/src/virtBootstrap/sources/docker_source.py b/src/virtBootstrap/sources/docker_source.py
index ec1a812..0eace81 100644
--- a/src/virtBootstrap/sources/docker_source.py
+++ b/src/virtBootstrap/sources/docker_source.py
@@ -77,7 +77,7 @@ class DockerSource(object):
self.no_cache = kwargs.get('no_cache', False)
self.progress = kwargs['progress'].update_progress
self.images_dir = utils.get_image_dir(self.no_cache)
- self.manifest = None
+ self.image_details = None
self.layers = []
self.checksums = []
@@ -91,30 +91,25 @@ class DockerSource(object):
Retrive manifest from registry and get layers' digest,
sum_type, size and file_path in a list.
"""
- self.manifest = utils.get_image_details(self.url, raw=True,
+ image_details = utils.get_image_details(self.url, raw=False,
insecure=self.insecure,
username=self.username,
password=self.password)
- if self.manifest['schemaVersion'] == 1:
- layers_list = self.manifest['fsLayers'][::-1]
- digest_field = 'blobSum'
- elif self.manifest['schemaVersion'] == 2:
- layers_list = self.manifest['layers']
- digest_field = 'digest'
- else:
- raise ValueError('Unsupported manifest schema.')
+ if not 'Layers' in image_details or not image_details['Layers']:
+ raise ValueError('No image layers.')
- for layer in layers_list:
- # Store checksums of layers
- layer_digest = layer[digest_field]
+ # Layers are in order:
+ # - root layer first, and then successive layered layers
+ # Ref: https://github.com/containers/image/blob/master/image/oci.go
+ for layer_digest in image_details['Layers']:
sum_type, layer_sum = layer_digest.split(':')
- self.checksums.append([sum_type, layer_sum])
+ self.checksums.append([sum_type, layer_sum]) # Store checksums
- # Store file path and size of each layer
+ # Layers are tar files with hashsum used as name
file_path = os.path.join(self.images_dir, layer_sum + '.tar')
- layer_size = layer.get('size', None)
- self.layers.append([file_path, layer_size])
+ # Store 'file path' and set placeholder for 'size'
+ self.layers.append([file_path, None])
def gen_valid_uri(self, uri):
"""
diff --git a/tests/docker_source.py b/tests/docker_source.py
index 9090988..c8f4e08 100644
--- a/tests/docker_source.py
+++ b/tests/docker_source.py
@@ -90,11 +90,8 @@ class CreateLayers(object):
"""
return {
"schemaVersion": 2,
- "layers": [
- {
- "digest":
- "sha256:" + os.path.basename(layer).split('.')[0]
- }
+ "Layers": [
+ "sha256:" + os.path.basename(layer).split('.')[0]
for layer in self.layers
]
}
@@ -340,7 +337,7 @@ class TestDockerSource(unittest.TestCase):
'progress': mock.Mock()
}
- manifest = {'schemaVersion': 2, 'layers': []}
+ manifest = {'schemaVersion': 2, 'Layers': ['sha256:a7050fc1']}
(src_instance,
m_uri, m_utils) = self._mock_retrieve_layers_info(manifest,
src_kwargs)
@@ -349,7 +346,7 @@ class TestDockerSource(unittest.TestCase):
'insecure': src_instance.insecure,
'username': src_instance.username,
'password': src_instance.password,
- 'raw': True
+ 'raw': False
}
m_utils['get_image_details'].assert_called_once_with(m_uri(), **kwargs)
@@ -365,11 +362,11 @@ class TestDockerSource(unittest.TestCase):
}
manifest = {
- 'schemaVersion': 1,
- 'fsLayers': [
- {'blobSum': 'sha256:75c416ea'},
- {'blobSum': 'sha256:c6ff40b6'},
- {'blobSum': 'sha256:a7050fc1'}
+ 'schemaVersion': 2,
+ 'Layers': [
+ 'sha256:a7050fc1',
+ 'sha256:c6ff40b6',
+ 'sha256:75c416ea'
]
}
@@ -382,47 +379,4 @@ class TestDockerSource(unittest.TestCase):
with mock.patch('os.path.getsize') as m_getsize:
m_getsize.return_value = None
src_instance = self._mock_retrieve_layers_info(manifest, kwargs)[0]
- self.assertEqual(src_instance.layers, expected_result)
-
- def test_retrieve_layers_info_schema_version_2(self):
- """
- Ensures that retrieve_layers_info() extracts the layers' information
- from manifest with schema version 2 a list with format:
- ["digest", "sum_type", "file_path", "size"].
- """
- kwargs = {
- 'uri': '',
- 'progress': mock.Mock()
- }
-
- manifest = {
- 'schemaVersion': 2,
- "layers": [
- {"size": 47103294, "digest": "sha256:75c416ea"},
- {"size": 814, "digest": "sha256:c6ff40b6"},
- {"size": 513, "digest": "sha256:a7050fc1"}
- ]
- }
-
- expected_result = [
- ['/images_path/75c416ea.tar', 47103294],
- ['/images_path/c6ff40b6.tar', 814],
- ['/images_path/a7050fc1.tar', 513]
- ]
-
- src_instance = self._mock_retrieve_layers_info(manifest, kwargs)[0]
- self.assertEqual(src_instance.layers, expected_result)
-
- def test_retrieve_layers_info_raise_error_on_invalid_schema_version(self):
- """
- Ensures that retrieve_layers_info() calls get_image_details()
- with all passed arguments.
- """
- kwargs = {
- 'uri': '',
- 'progress': mock.Mock()
- }
-
- manifest = {'schemaVersion': 3}
- with self.assertRaises(ValueError):
- self._mock_retrieve_layers_info(manifest, kwargs)
+ self.assertEqual(src_instance.layers, expected_result)
\ No newline at end of file
--
2.13.6
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