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quay/image/docker/schema2/config.py
Joseph Schorr 171c7e5238 Further fixes for unicode handling in manifests
We were occasionally trying to compute schema 2 version 1 signatures on the *unicode* representation, which was failing the signature check. This PR adds a new wrapper type called `Bytes`, which all manifests must take in, and which handles the unicodes vs encoded utf-8 stuff in a central location. This PR also adds a test for the manifest that was breaking in production.
2019-01-09 15:14:41 -05:00

275 lines
8.7 KiB
Python

"""
Implements validation and conversion for the Schema2 config JSON.
Example:
{
"architecture": "amd64",
"config": {
"Hostname": "",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"HTTP_PROXY=http:\/\/localhost:8080",
"http_proxy=http:\/\/localhost:8080",
"PATH=\/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\/usr\/bin:\/sbin:\/bin"
],
"Cmd": [
"sh"
],
"Image": "",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
}
},
"container": "b7a43694b435c8e9932615643f61f975a9213e453b15cd6c2a386f144a2d2de9",
"container_config": {
"Hostname": "b7a43694b435",
"Domainname": "",
"User": "",
"AttachStdin": true,
"AttachStdout": true,
"AttachStderr": true,
"Tty": true,
"OpenStdin": true,
"StdinOnce": true,
"Env": [
"HTTP_PROXY=http:\/\/localhost:8080",
"http_proxy=http:\/\/localhost:8080",
"PATH=\/usr\/local\/sbin:\/usr\/local\/bin:\/usr\/sbin:\/usr\/bin:\/sbin:\/bin"
],
"Cmd": [
"sh"
],
"Image": "somenamespace\/somerepo",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
}
},
"created": "2018-04-16T10:41:19.079522722Z",
"docker_version": "17.09.0-ce",
"history": [
{
"created": "2018-04-03T18:37:09.284840891Z",
"created_by": "\/bin\/sh -c #(nop) ADD file:9e4ca21cbd24dc05b454b6be21c7c639216ae66559b21ba24af0d665c62620dc in \/ "
},
{
"created": "2018-04-03T18:37:09.613317719Z",
"created_by": "\/bin\/sh -c #(nop) CMD [\"sh\"]",
"empty_layer": true
},
{
"created": "2018-04-16T10:37:44.418262777Z",
"created_by": "sh"
},
{
"created": "2018-04-16T10:41:19.079522722Z",
"created_by": "sh"
}
],
"os": "linux",
"rootfs": {
"type": "layers",
"diff_ids": [
"sha256:3e596351c689c8827a3c9635bc1083cff17fa4a174f84f0584bd0ae6f384195b",
"sha256:4552be273c71275a88de0b8c8853dcac18cb74d5790f5383d9b38d4ac55062d5",
"sha256:1319c76152ca37fbeb7fb71e0ffa7239bc19ffbe3b95c00417ece39d89d06e6e"
]
}
}
"""
import copy
import json
import hashlib
from collections import namedtuple
from jsonschema import validate as validate_schema, ValidationError
from dateutil.parser import parse as parse_date
from digest import digest_tools
from image.docker import ManifestException
from util.bytes import Bytes
DOCKER_SCHEMA2_CONFIG_HISTORY_KEY = "history"
DOCKER_SCHEMA2_CONFIG_ROOTFS_KEY = "rootfs"
DOCKER_SCHEMA2_CONFIG_CREATED_KEY = "created"
DOCKER_SCHEMA2_CONFIG_CREATED_BY_KEY = "created_by"
DOCKER_SCHEMA2_CONFIG_COMMENT_KEY = "comment"
DOCKER_SCHEMA2_CONFIG_AUTHOR_KEY = "author"
DOCKER_SCHEMA2_CONFIG_EMPTY_LAYER_KEY = "empty_layer"
DOCKER_SCHEMA2_CONFIG_TYPE_KEY = "type"
LayerHistory = namedtuple('LayerHistory', ['created', 'created_datetime', 'command', 'is_empty',
'author', 'comment', 'raw_entry'])
class MalformedSchema2Config(ManifestException):
"""
Raised when a config fails an assertion that should be true according to the Docker Manifest
v2.2 Config Specification.
"""
pass
class DockerSchema2Config(object):
METASCHEMA = {
'type': 'object',
'description': 'The container configuration found in a schema 2 manifest',
'required': [DOCKER_SCHEMA2_CONFIG_HISTORY_KEY, DOCKER_SCHEMA2_CONFIG_ROOTFS_KEY],
'properties': {
DOCKER_SCHEMA2_CONFIG_HISTORY_KEY: {
'type': 'array',
'description': 'The history used to create the container image',
'items': {
'type': 'object',
'properties': {
DOCKER_SCHEMA2_CONFIG_EMPTY_LAYER_KEY: {
'type': 'boolean',
'description': 'If present, this layer is empty',
},
DOCKER_SCHEMA2_CONFIG_CREATED_KEY: {
'type': 'string',
'description': 'The date/time that the layer was created',
'format': 'date-time',
'x-example': '2018-04-03T18:37:09.284840891Z',
},
DOCKER_SCHEMA2_CONFIG_CREATED_BY_KEY: {
'type': 'string',
'description': 'The command used to create the layer',
'x-example': '\/bin\/sh -c #(nop) ADD file:somesha in /',
},
DOCKER_SCHEMA2_CONFIG_COMMENT_KEY: {
'type': 'string',
'description': 'Comment describing the layer',
},
DOCKER_SCHEMA2_CONFIG_AUTHOR_KEY: {
'type': 'string',
'description': 'The author of the layer',
},
},
'additionalProperties': True,
},
},
DOCKER_SCHEMA2_CONFIG_ROOTFS_KEY: {
'type': 'object',
'description': 'Describes the root filesystem for this image',
'properties': {
DOCKER_SCHEMA2_CONFIG_TYPE_KEY: {
'type': 'string',
'description': 'The type of the root file system entries',
},
},
'required': [DOCKER_SCHEMA2_CONFIG_TYPE_KEY],
'additionalProperties': True,
},
},
'additionalProperties': True,
}
def __init__(self, config_bytes):
assert isinstance(config_bytes, Bytes)
self._config_bytes = config_bytes
try:
self._parsed = json.loads(config_bytes.as_unicode())
except ValueError as ve:
raise MalformedSchema2Config('malformed config data: %s' % ve)
try:
validate_schema(self._parsed, DockerSchema2Config.METASCHEMA)
except ValidationError as ve:
raise MalformedSchema2Config('config data does not match schema: %s' % ve)
@property
def digest(self):
""" Returns the digest of this config object. """
return digest_tools.sha256_digest(self._config_bytes.as_encoded_str())
@property
def size(self):
""" Returns the size of this config object. """
return len(self._config_bytes.as_encoded_str())
@property
def bytes(self):
""" Returns the bytes of this config object. """
return self._config_bytes
@property
def labels(self):
""" Returns a dictionary of all the labels defined in this configuration. """
return self._parsed.get('config', {}).get('Labels', {}) or {}
@property
def has_empty_layer(self):
""" Returns whether this config contains an empty layer. """
for history_entry in self._parsed[DOCKER_SCHEMA2_CONFIG_HISTORY_KEY]:
if history_entry.get(DOCKER_SCHEMA2_CONFIG_EMPTY_LAYER_KEY, False):
return True
return False
@property
def history(self):
""" Returns the history of the image, started at the base layer. """
for history_entry in self._parsed[DOCKER_SCHEMA2_CONFIG_HISTORY_KEY]:
created_datetime = parse_date(history_entry[DOCKER_SCHEMA2_CONFIG_CREATED_KEY])
yield LayerHistory(created_datetime=created_datetime,
created=history_entry.get(DOCKER_SCHEMA2_CONFIG_CREATED_KEY),
command=history_entry.get(DOCKER_SCHEMA2_CONFIG_CREATED_BY_KEY),
author=history_entry.get(DOCKER_SCHEMA2_CONFIG_AUTHOR_KEY),
comment=history_entry.get(DOCKER_SCHEMA2_CONFIG_COMMENT_KEY),
is_empty=history_entry.get(DOCKER_SCHEMA2_CONFIG_EMPTY_LAYER_KEY, False),
raw_entry=history_entry)
def build_v1_compatibility(self, history, v1_id, v1_parent_id, is_leaf, compressed_size=None):
""" Builds the V1 compatibility block for the given layer.
"""
# If the layer is the leaf, it gets the full config (minus 2 fields). Otherwise, it gets only
# IDs.
v1_compatibility = copy.deepcopy(self._parsed) if is_leaf else {}
v1_compatibility['id'] = v1_id
if v1_parent_id is not None:
v1_compatibility['parent'] = v1_parent_id
if 'created' not in v1_compatibility and history.created:
v1_compatibility['created'] = history.created
if 'author' not in v1_compatibility and history.author:
v1_compatibility['author'] = history.author
if 'comment' not in v1_compatibility and history.comment:
v1_compatibility['comment'] = history.comment
if 'throwaway' not in v1_compatibility and history.is_empty:
v1_compatibility['throwaway'] = True
if 'container_config' not in v1_compatibility:
v1_compatibility['container_config'] = {
'Cmd': [history.command],
}
if compressed_size is not None:
v1_compatibility['Size'] = compressed_size
# The history and rootfs keys are schema2-config specific.
v1_compatibility.pop(DOCKER_SCHEMA2_CONFIG_HISTORY_KEY, None)
v1_compatibility.pop(DOCKER_SCHEMA2_CONFIG_ROOTFS_KEY, None)
return v1_compatibility