summaryrefslogtreecommitdiffstats
path: root/taskcluster/taskgraph/util/docker.py
blob: df97e57bcf72fd9258a0f90fdc8f9b1f8bc06d5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.

from __future__ import absolute_import, print_function, unicode_literals

import hashlib
import os
import shutil
import subprocess
import tarfile
import tempfile

from mozpack.archive import (
    create_tar_gz_from_files,
)


GECKO = os.path.realpath(os.path.join(__file__, '..', '..', '..', '..'))
DOCKER_ROOT = os.path.join(GECKO, 'testing', 'docker')
INDEX_PREFIX = 'docker.images.v2'
ARTIFACT_URL = 'https://queue.taskcluster.net/v1/task/{}/artifacts/{}'


def docker_image(name, default_version=None):
    '''Determine the docker image name, including repository and tag, from an
    in-tree docker file.'''
    try:
        with open(os.path.join(DOCKER_ROOT, name, 'REGISTRY')) as f:
            registry = f.read().strip()
    except IOError:
        with open(os.path.join(DOCKER_ROOT, 'REGISTRY')) as f:
            registry = f.read().strip()

    try:
        with open(os.path.join(DOCKER_ROOT, name, 'VERSION')) as f:
            version = f.read().strip()
    except IOError:
        if not default_version:
            raise

        version = default_version

    return '{}/{}:{}'.format(registry, name, version)


def generate_context_hash(topsrcdir, image_path, image_name):
    """Generates a sha256 hash for context directory used to build an image."""

    # It is a bit unfortunate we have to create a temp file here - it would
    # be nicer to use an in-memory buffer.
    fd, p = tempfile.mkstemp()
    os.close(fd)
    try:
        return create_context_tar(topsrcdir, image_path, p, image_name)
    finally:
        os.unlink(p)


def create_context_tar(topsrcdir, context_dir, out_path, prefix):
    """Create a context tarball.

    A directory ``context_dir`` containing a Dockerfile will be assembled into
    a gzipped tar file at ``out_path``. Files inside the archive will be
    prefixed by directory ``prefix``.

    We also scan the source Dockerfile for special syntax that influences
    context generation.

    If a line in the Dockerfile has the form ``# %include <path>``,
    the relative path specified on that line will be matched against
    files in the source repository and added to the context under the
    path ``topsrcdir/``. If an entry is a directory, we add all files
    under that directory.

    Returns the SHA-256 hex digest of the created archive.
    """
    archive_files = {}

    for root, dirs, files in os.walk(context_dir):
        for f in files:
            source_path = os.path.join(root, f)
            rel = source_path[len(context_dir) + 1:]
            archive_path = os.path.join(prefix, rel)
            archive_files[archive_path] = source_path

    # Parse Dockerfile for special syntax of extra files to include.
    with open(os.path.join(context_dir, 'Dockerfile'), 'rb') as fh:
        for line in fh:
            line = line.rstrip()
            if not line.startswith('# %include'):
                continue

            p = line[len('# %include '):].strip()
            if os.path.isabs(p):
                raise Exception('extra include path cannot be absolute: %s' % p)

            fs_path = os.path.normpath(os.path.join(topsrcdir, p))
            # Check for filesystem traversal exploits.
            if not fs_path.startswith(topsrcdir):
                raise Exception('extra include path outside topsrcdir: %s' % p)

            if not os.path.exists(fs_path):
                raise Exception('extra include path does not exist: %s' % p)

            if os.path.isdir(fs_path):
                for root, dirs, files in os.walk(fs_path):
                    for f in files:
                        source_path = os.path.join(root, f)
                        archive_path = os.path.join(prefix, 'topsrcdir', p, f)
                        archive_files[archive_path] = source_path
            else:
                archive_path = os.path.join(prefix, 'topsrcdir', p)
                archive_files[archive_path] = fs_path

    with open(out_path, 'wb') as fh:
        create_tar_gz_from_files(fh, archive_files, '%s.tar.gz' % prefix)

    h = hashlib.sha256()
    with open(out_path, 'rb') as fh:
        while True:
            data = fh.read(32768)
            if not data:
                break
            h.update(data)
    return h.hexdigest()


def build_from_context(docker_bin, context_path, prefix, tag=None):
    """Build a Docker image from a context archive.

    Given the path to a `docker` binary, a image build tar.gz (produced with
    ``create_context_tar()``, a prefix in that context containing files, and
    an optional ``tag`` for the produced image, build that Docker image.
    """
    d = tempfile.mkdtemp()
    try:
        with tarfile.open(context_path, 'r:gz') as tf:
            tf.extractall(d)

        # If we wanted to do post-processing of the Dockerfile, this is
        # where we'd do it.

        args = [
            docker_bin,
            'build',
            # Use --no-cache so we always get the latest package updates.
            '--no-cache',
        ]

        if tag:
            args.extend(['-t', tag])

        args.append('.')

        res = subprocess.call(args, cwd=os.path.join(d, prefix))
        if res:
            raise Exception('error building image')
    finally:
        shutil.rmtree(d)