xref: /qemu/tests/functional/qemu_test/asset.py (revision 9903217a4ed013228d95d8b1876b6053b2bc5e95) 
1# Test utilities for fetching & caching assets
2#
3# Copyright 2024 Red Hat, Inc.
4#
5# This work is licensed under the terms of the GNU GPL, version 2 or
6# later.  See the COPYING file in the top-level directory.
7
8import hashlib
9import logging
10import os
11import subprocess
12import urllib.request
13from pathlib import Path
14from shutil import copyfileobj
15
16
17# Instances of this class must be declared as class level variables
18# starting with a name "ASSET_". This enables the pre-caching logic
19# to easily find all referenced assets and download them prior to
20# execution of the tests.
21class Asset:
22
23    def __init__(self, url, hashsum):
24        self.url = url
25        self.hash = hashsum
26        cache_dir_env = os.getenv('QEMU_TEST_CACHE_DIR')
27        if cache_dir_env:
28            self.cache_dir = Path(cache_dir_env, "download")
29        else:
30            self.cache_dir = Path(Path("~").expanduser(),
31                                  ".cache", "qemu", "download")
32        self.cache_file = Path(self.cache_dir, hashsum)
33        self.log = logging.getLogger('qemu-test')
34
35    def __repr__(self):
36        return "Asset: url=%s hash=%s cache=%s" % (
37            self.url, self.hash, self.cache_file)
38
39    def _check(self, cache_file):
40        if self.hash is None:
41            return True
42        if len(self.hash) == 64:
43            sum_prog = 'sha256sum'
44        elif len(self.hash) == 128:
45            sum_prog = 'sha512sum'
46        else:
47            raise Exception("unknown hash type")
48
49        checksum = subprocess.check_output(
50            [sum_prog, str(cache_file)]).split()[0]
51        return self.hash == checksum.decode("utf-8")
52
53    def valid(self):
54        return self.cache_file.exists() and self._check(self.cache_file)
55
56    def fetch(self):
57        if not self.cache_dir.exists():
58            self.cache_dir.mkdir(parents=True, exist_ok=True)
59
60        if self.valid():
61            self.log.debug("Using cached asset %s for %s",
62                           self.cache_file, self.url)
63            return str(self.cache_file)
64
65        self.log.info("Downloading %s to %s...", self.url, self.cache_file)
66        tmp_cache_file = self.cache_file.with_suffix(".download")
67
68        try:
69            resp = urllib.request.urlopen(self.url)
70        except Exception as e:
71            self.log.error("Unable to download %s: %s", self.url, e)
72            raise
73
74        try:
75            with tmp_cache_file.open("wb+") as dst:
76                copyfileobj(resp, dst)
77        except:
78            tmp_cache_file.unlink()
79            raise
80        try:
81            # Set these just for informational purposes
82            os.setxattr(str(tmp_cache_file), "user.qemu-asset-url",
83                        self.url.encode('utf8'))
84            os.setxattr(str(tmp_cache_file), "user.qemu-asset-hash",
85                        self.hash.encode('utf8'))
86        except Exception as e:
87            self.log.debug("Unable to set xattr on %s: %s", tmp_cache_file, e)
88            pass
89
90        if not self._check(tmp_cache_file):
91            tmp_cache_file.unlink()
92            raise Exception("Hash of %s does not match %s" %
93                            (self.url, self.hash))
94        tmp_cache_file.replace(self.cache_file)
95
96        self.log.info("Cached %s at %s" % (self.url, self.cache_file))
97        return str(self.cache_file)
98