1# Copyright (c) 2012 The Chromium OS Authors. All rights reserved.
2# Use of this source code is governed by a BSD-style license that can be
3# found in the LICENSE file.
4
5"""Module for discovering Chrome OS test images and payloads."""
6
7import logging
8import re
9
10import common
11from autotest_lib.client.common_lib import global_config
12from autotest_lib.utils import external_packages
13
14from autotest_lib.site_utils.autoupdate import import_common
15devserver = import_common.download_and_import('devserver',
16                                              external_packages.DevServerRepo())
17from devserver import gsutil_util
18
19
20# A string indicating a zip-file boundary within a URI path. This string must
21# end with a '/', in order for standard basename code to work correctly for
22# zip-encapsulated paths.
23ZIPFILE_BOUNDARY = '//'
24ARCHIVE_URL_FORMAT = '%(archive_prefix)s/%(version)s'
25
26
27class TestImageError(BaseException):
28    """Raised on any error in this module."""
29    pass
30
31
32class NotSingleItem(Exception):
33    """Raised when we want a single item but got multiple."""
34
35
36def get_default_archive_url(board, build_version):
37    """Returns the default archive_url for the given board and build_version .
38
39    @param board: the platform/board name
40    @param build_version: the full build version i.e. R27-3823.0.0-a2.
41    """
42    archive_base = global_config.global_config.get_config_value(
43            'CROS', 'image_storage_server')
44    archive_base = archive_base.rstrip('/') # Remove any trailing /'s.
45
46    # TODO(garnold) adjustment to -he variant board names; should be removed
47    # once we switch to using artifacts from gs://chromeos-images/
48    # (see chromium-os:38222)
49    board = re.sub('-he$', '_he', board)
50    archive_prefix = archive_base + '/%s-release' % board
51    return ARCHIVE_URL_FORMAT % dict(
52            archive_prefix=archive_prefix, version=build_version)
53
54
55def get_archive_url_from_prefix(archive_prefix, build_version):
56    """Returns the gs archive_url given a particular archive_prefix.
57
58    @param archive_prefix: Use the archive_prefix as the base of your URL
59
60                           construction (instead of config + board-release) e.g.
61                           gs://my_location/my_super_awesome_directory.
62    @param build_version: the full build version i.e. R27-3823.0.0-a2.
63    """
64    return ARCHIVE_URL_FORMAT % dict(
65            archive_prefix=archive_prefix, version=build_version)
66
67
68def gs_ls(pattern, archive_url, single):
69    """Returns a list of URIs that match a given pattern.
70
71    @param pattern: a regexp pattern to match (feeds into re.match).
72    @param archive_url: the gs uri where to search (see ARCHIVE_URL_FORMAT).
73    @param single: if true, expect a single match and return it.
74
75    @return A list of URIs (possibly an empty list).
76
77    """
78    try:
79        logging.debug('Searching for pattern %s from url %s', pattern,
80                      archive_url)
81        uri_list = gsutil_util.GetGSNamesWithWait(
82                pattern, archive_url, err_str=__name__, timeout=1)
83        # Convert to the format our clients expect (full archive path).
84        if uri_list:
85            if not single or (single and len(uri_list) == 1):
86                return ['/'.join([archive_url, u]) for u in uri_list]
87            else:
88                raise NotSingleItem()
89
90        return []
91    except gsutil_util.PatternNotSpecific as e:
92        raise TestImageError(str(e))
93    except gsutil_util.GSUtilError:
94        return []
95
96
97def find_payload_uri(archive_url, delta=False, single=False):
98    """Finds test payloads corresponding to a given board/release.
99
100    @param archive_url: Archive_url directory to find the payload.
101    @param delta: if true, seek delta payloads to the given release
102    @param single: if true, expect a single match and return it, otherwise
103           None
104
105    @return A (possibly empty) list of URIs, or a single (possibly None) URI if
106            |single| is True.
107
108    @raise TestImageError if an error has occurred.
109
110    """
111    if delta:
112        pattern = '*_delta_*'
113    else:
114        pattern = '*_full_*'
115
116    payload_uri_list = gs_ls(pattern, archive_url, single)
117    if not payload_uri_list:
118        return None if single else []
119
120    return payload_uri_list[0] if single else payload_uri_list
121
122
123def find_image_uri(archive_url):
124    """Returns a URI to a test image.
125
126    @param archive_url: archive_url directory to find the payload.
127
128    @return A URI to the desired image if found, None otherwise. It will most
129            likely be a file inside an image archive (image.zip), in which case
130            we'll be using ZIPFILE_BOUNDARY ('//') to denote a zip-encapsulated
131            file, for example:
132            gs://chromeos-image-archive/.../image.zip//chromiumos_test_image.bin
133
134    @raise TestImageError if an error has occurred.
135
136    """
137    image_archive = gs_ls('image.zip', archive_url, single=True)
138    if not image_archive:
139        return None
140
141    return (image_archive[0] + ZIPFILE_BOUNDARY + 'chromiumos_test_image.bin')
142