nvchecker/nvchecker_source/container.py

103 lines
3.1 KiB
Python

# MIT licensed
# Copyright (c) 2020 Chih-Hsuan Yen <yan12125 at gmail dot com>
from typing import Dict, List, NamedTuple, Optional, Tuple
from urllib.request import parse_http_list
from urllib.parse import urljoin
from nvchecker.api import session, HTTPError
class AuthInfo(NamedTuple):
service: Optional[str]
realm: str
def parse_www_authenticate_header(header: str) -> Tuple[str, Dict[str, str]]:
'''
Parse WWW-Authenticate header used in OAuth2 authentication for container
registries. This is NOT RFC-compliant!
Simplified from http.parse_www_authenticate_header in Werkzeug (BSD license)
'''
auth_type, auth_info = header.split(None, 1)
result = {}
for item in parse_http_list(auth_info):
name, value = item.split("=", 1)
if value[:1] == value[-1:] == '"':
value = value[1:-1]
result[name] = value
return auth_type, result
# Inspired by https://stackoverflow.com/a/51921869
# Reference: https://github.com/containers/image/blob/v5.6.0/docker/docker_client.go
class UnsupportedAuthenticationError(NotImplementedError):
def __init__(self):
super().__init__('Only Bearer authentication supported for now')
async def get_registry_auth_info(registry_host: str) -> AuthInfo:
auth_service = auth_realm = None
try:
await session.get(f'https://{registry_host}/v2/')
raise UnsupportedAuthenticationError # No authentication needed
except HTTPError as e:
if e.code != 401:
raise
auth_type, auth_info = parse_www_authenticate_header(e.response.headers['WWW-Authenticate'])
if auth_type.lower() != 'bearer':
raise UnsupportedAuthenticationError
# Although 'service' is needed as per https://docs.docker.com/registry/spec/auth/token/,
# ghcr.io (GitHub container registry) does not provide it
auth_service = auth_info.get('service')
auth_realm = auth_info['realm']
return AuthInfo(auth_service, auth_realm)
async def get_container_tags(info: Tuple[str, str, AuthInfo]) -> List[str]:
image_path, registry_host, auth_info = info
auth_params = {
'scope': f'repository:{image_path}:pull',
}
if auth_info.service:
auth_params['service'] = auth_info.service
res = await session.get(auth_info.realm, params=auth_params)
token = res.json()['token']
tags = []
url = f'https://{registry_host}/v2/{image_path}/tags/list'
while True:
res = await session.get(url, headers={
'Authorization': f'Bearer {token}',
'Accept': 'application/json',
})
tags += res.json()['tags']
link = res.headers.get('Link')
if link is None:
break
else:
url = urljoin(url, parse_next_link(link))
return tags
def parse_next_link(value: str) -> str:
ending = '>; rel="next"'
if value.endswith(ending):
return value[1:-len(ending)]
else:
raise ValueError(value)
async def get_version(name, conf, *, cache, **kwargs):
image_path = conf.get('container', name)
registry_host = conf.get('registry', 'docker.io')
if registry_host == 'docker.io':
registry_host = 'registry-1.docker.io'
auth_info = await cache.get(registry_host, get_registry_auth_info)
key = image_path, registry_host, auth_info
return await cache.get(key, get_container_tags)