path: root/python/servo/package_commands.py

# Copyright 2013 The Servo Project Developers. See the COPYRIGHT
# file at the top-level directory of this distribution.
#
# Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
# http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
# <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
# option. This file may not be copied, modified, or distributed
# except according to those terms.

from __future__ import absolute_import, print_function, unicode_literals

from datetime import datetime
import hashlib
import json
import os
import os.path as path
import platform
import shutil
import subprocess
import sys
import tempfile
import urllib

from mach.decorators import (
    CommandArgument,
    CommandProvider,
    Command,
)
from mach.registrar import Registrar
# Note: mako cannot be imported at the top level because it breaks mach bootstrap
sys.path.append(path.join(path.dirname(__file__), "..", "..",
                          "components", "style", "properties", "Mako-0.9.1.zip"))

from servo.command_base import (
    archive_deterministically,
    BuildNotFound,
    cd,
    CommandBase,
    is_macosx,
    is_windows,
)
from servo.util import delete


PACKAGES = {
    'android': [
        'target/android/armv7-linux-androideabi/release/servoapp.apk',
        'target/android/armv7-linux-androideabi/release/servoview.aar',
    ],
    'linux': [
        'target/release/servo-tech-demo.tar.gz',
    ],
    'mac': [
        'target/release/servo-tech-demo.dmg',
    ],
    'macbrew': [
        'target/release/brew/servo.tar.gz',
    ],
    'magicleap': [
        'target/magicleap/aarch64-linux-android/release/Servo.mpk',
    ],
    'maven': [
        'target/android/gradle/servoview/maven/org/mozilla/servoview/servoview-armv7/',
        'target/android/gradle/servoview/maven/org/mozilla/servoview/servoview-x86/',
    ],
    'windows-msvc': [
        r'target\release\msi\Servo.exe',
        r'target\release\msi\Servo.zip',
    ],
}


TemporaryDirectory = None
if sys.version_info >= (3, 2):
    TemporaryDirectory = tempfile.TemporaryDirectory
else:
    import contextlib

    # Not quite as robust as tempfile.TemporaryDirectory,
    # but good enough for most purposes
    @contextlib.contextmanager
    def TemporaryDirectory(**kwargs):
        dir_name = tempfile.mkdtemp(**kwargs)
        try:
            yield dir_name
        except Exception as e:
            shutil.rmtree(dir_name)
            raise e


def otool(s):
    o = subprocess.Popen(['/usr/bin/otool', '-L', s], stdout=subprocess.PIPE)
    for l in o.stdout:
        if l[0] == '\t':
            yield l.split(' ', 1)[0][1:]


def listfiles(directory):
    return [f for f in os.listdir(directory)
            if path.isfile(path.join(directory, f))]


def install_name_tool(old, new, binary):
    try:
        subprocess.check_call(['install_name_tool', '-change', old, '@executable_path/' + new, binary])
    except subprocess.CalledProcessError as e:
        print("install_name_tool exited with return value %d" % e.returncode)


def is_system_library(lib):
    return lib.startswith("/System/Library") or lib.startswith("/usr/lib")


def change_non_system_libraries_path(libraries, relative_path, binary):
    for lib in libraries:
        if is_system_library(lib):
            continue
        new_path = path.join(relative_path, path.basename(lib))
        install_name_tool(lib, new_path, binary)


def copy_dependencies(binary_path, lib_path):
    relative_path = path.relpath(lib_path, path.dirname(binary_path)) + "/"

    # Update binary libraries
    binary_dependencies = set(otool(binary_path))
    change_non_system_libraries_path(binary_dependencies, relative_path, binary_path)

    # Update dependencies libraries
    need_checked = binary_dependencies
    checked = set()
    while need_checked:
        checking = set(need_checked)
        need_checked = set()
        for f in checking:
            # No need to check these for their dylibs
            if is_system_library(f):
                continue
            need_relinked = set(otool(f))
            new_path = path.join(lib_path, path.basename(f))
            if not path.exists(new_path):
                shutil.copyfile(f, new_path)
            change_non_system_libraries_path(need_relinked, relative_path, new_path)
            need_checked.update(need_relinked)
        checked.update(checking)
        need_checked.difference_update(checked)


def copy_windows_dependencies(binary_path, destination):
    for f in os.listdir(binary_path):
        if os.path.isfile(path.join(binary_path, f)) and f.endswith(".dll"):
            shutil.copy(path.join(binary_path, f), destination)


def change_prefs(resources_path, platform, vr=False):
    print("Swapping prefs")
    prefs_path = path.join(resources_path, "prefs.json")
    package_prefs_path = path.join(resources_path, "package-prefs.json")
    with open(prefs_path) as prefs, open(package_prefs_path) as package_prefs:
        prefs = json.load(prefs)
        pref_sets = []
        package_prefs = json.load(package_prefs)
        if "all" in package_prefs:
            pref_sets += [package_prefs["all"]]
        if vr and "vr" in package_prefs:
            pref_sets += [package_prefs["vr"]]
        if platform in package_prefs:
            pref_sets += [package_prefs[platform]]
        for pref_set in pref_sets:
            for pref in pref_set:
                if pref in prefs:
                    prefs[pref] = pref_set[pref]
        with open(prefs_path, "w") as out:
            json.dump(prefs, out, sort_keys=True, indent=2)
    delete(package_prefs_path)


@CommandProvider
class PackageCommands(CommandBase):
    @Command('package',
             description='Package Servo',
             category='package')
    @CommandArgument('--release', '-r', action='store_true',
                     help='Package the release build')
    @CommandArgument('--dev', '-d', action='store_true',
                     help='Package the dev build')
    @CommandArgument('--android',
                     default=None,
                     action='store_true',
                     help='Package Android')
    @CommandArgument('--magicleap',
                     default=None,
                     action='store_true',
                     help='Package Magic Leap')
    @CommandArgument('--target', '-t',
                     default=None,
                     help='Package for given target platform')
    @CommandArgument('--flavor', '-f',
                     default=None,
                     help='Package using the given Gradle flavor')
    @CommandArgument('--maven',
                     default=None,
                     action='store_true',
                     help='Create a local Maven repository')
    def package(self, release=False, dev=False, android=None, magicleap=None, debug=False,
                debugger=None, target=None, flavor=None, maven=False):
        if android is None:
            android = self.config["build"]["android"]
        if target and android:
            print("Please specify either --target or --android.")
            sys.exit(1)
        if not android:
            android = self.handle_android_target(target)
        else:
            target = self.config["android"]["target"]
        if target and magicleap:
            print("Please specify either --target or --magicleap.")
            sys.exit(1)
        if magicleap:
            target = "aarch64-linux-android"
        env = self.build_env(target=target)
        binary_path = self.get_binary_path(release, dev, target=target, android=android, magicleap=magicleap)
        dir_to_root = self.get_top_dir()
        target_dir = path.dirname(binary_path)
        if magicleap:
            if platform.system() not in ["Darwin"]:
                raise Exception("Magic Leap builds are only supported on macOS.")
            if not env.get("MAGICLEAP_SDK"):
                raise Exception("Magic Leap builds need the MAGICLEAP_SDK environment variable")
            if not env.get("MLCERT"):
                raise Exception("Magic Leap builds need the MLCERT environment variable")
            # GStreamer configuration
            env.setdefault("GSTREAMER_DIR", path.join(
                self.get_target_dir(), "magicleap", target, "native", "gstreamer-1.16.0"
            ))

            mabu = path.join(env.get("MAGICLEAP_SDK"), "mabu")
            packages = [
                "./support/magicleap/Servo.package",
            ]
            if dev:
                build_type = "lumin_debug"
            else:
                build_type = "lumin_release"
            for package in packages:
                argv = [
                    mabu,
                    "-o", target_dir,
                    "-t", build_type,
                    "-r",
                    "GSTREAMER_DIR=" + env["GSTREAMER_DIR"],
                    package
                ]
                try:
                    subprocess.check_call(argv, env=env)
                except subprocess.CalledProcessError as e:
                    print("Packaging Magic Leap exited with return value %d" % e.returncode)
                    return e.returncode
        elif android:
            android_target = self.config["android"]["target"]
            if "aarch64" in android_target:
                build_type = "Arm64"
            elif "armv7" in android_target:
                build_type = "Armv7"
            elif "i686" in android_target:
                build_type = "x86"
            else:
                build_type = "Arm"

            if dev:
                build_mode = "Debug"
            else:
                build_mode = "Release"

            flavor_name = "Main"
            if flavor is not None:
                flavor_name = flavor.title()

            vr = flavor == "googlevr" or flavor == "oculusvr"

            dir_to_resources = path.join(self.get_top_dir(), 'target', 'android', 'resources')
            if path.exists(dir_to_resources):
                delete(dir_to_resources)

            shutil.copytree(path.join(dir_to_root, 'resources'), dir_to_resources)
            change_prefs(dir_to_resources, "android", vr=vr)

            variant = ":assemble" + flavor_name + build_type + build_mode
            apk_task_name = ":servoapp" + variant
            aar_task_name = ":servoview" + variant
            maven_task_name = ":servoview:uploadArchive"
            argv = ["./gradlew", "--no-daemon", apk_task_name, aar_task_name]
            if maven:
                argv.append(maven_task_name)
            try:
                with cd(path.join("support", "android", "apk")):
                    subprocess.check_call(argv, env=env)
            except subprocess.CalledProcessError as e:
                print("Packaging Android exited with return value %d" % e.returncode)
                return e.returncode
        elif is_macosx():
            print("Creating Servo.app")
            dir_to_dmg = path.join(target_dir, 'dmg')
            dir_to_app = path.join(dir_to_dmg, 'Servo.app')
            dir_to_resources = path.join(dir_to_app, 'Contents', 'Resources')
            if path.exists(dir_to_dmg):
                print("Cleaning up from previous packaging")
                delete(dir_to_dmg)

            print("Copying files")
            shutil.copytree(path.join(dir_to_root, 'resources'), dir_to_resources)
            shutil.copy2(path.join(dir_to_root, 'Info.plist'), path.join(dir_to_app, 'Contents', 'Info.plist'))

            content_dir = path.join(dir_to_app, 'Contents', 'MacOS')
            os.makedirs(content_dir)
            shutil.copy2(binary_path, content_dir)

            change_prefs(dir_to_resources, "macosx")

            print("Finding dylibs and relinking")
            copy_dependencies(path.join(content_dir, 'servo'), content_dir)

            print("Adding version to Credits.rtf")
            version_command = [binary_path, '--version']
            p = subprocess.Popen(version_command,
                                 stdout=subprocess.PIPE,
                                 stderr=subprocess.PIPE,
                                 universal_newlines=True)
            version, stderr = p.communicate()
            if p.returncode != 0:
                raise Exception("Error occurred when getting Servo version: " + stderr)
            version = "Nightly version: " + version

            import mako.template
            template_path = path.join(dir_to_resources, 'Credits.rtf.mako')
            credits_path = path.join(dir_to_resources, 'Credits.rtf')
            with open(template_path) as template_file:
                template = mako.template.Template(template_file.read())
                with open(credits_path, "w") as credits_file:
                    credits_file.write(template.render(version=version))
            delete(template_path)

            print("Creating dmg")
            os.symlink('/Applications', path.join(dir_to_dmg, 'Applications'))
            dmg_path = path.join(target_dir, "servo-tech-demo.dmg")

            if path.exists(dmg_path):
                print("Deleting existing dmg")
                os.remove(dmg_path)

            try:
                subprocess.check_call(['hdiutil', 'create',
                                       '-volname', 'Servo',
                                       '-megabytes', '900',
                                       dmg_path,
                                       '-srcfolder', dir_to_dmg])
            except subprocess.CalledProcessError as e:
                print("Packaging MacOS dmg exited with return value %d" % e.returncode)
                return e.returncode
            print("Cleaning up")
            delete(dir_to_dmg)
            print("Packaged Servo into " + dmg_path)

            print("Creating brew package")
            dir_to_brew = path.join(target_dir, 'brew_tmp')
            dir_to_tar = path.join(target_dir, 'brew')
            if not path.exists(dir_to_tar):
                os.makedirs(dir_to_tar)
            tar_path = path.join(dir_to_tar, "servo.tar.gz")
            if path.exists(dir_to_brew):
                print("Cleaning up from previous packaging")
                delete(dir_to_brew)
            if path.exists(tar_path):
                print("Deleting existing package")
                os.remove(tar_path)
            shutil.copytree(path.join(dir_to_root, 'resources'), path.join(dir_to_brew, 'resources'))
            os.makedirs(path.join(dir_to_brew, 'bin'))
            shutil.copy2(binary_path, path.join(dir_to_brew, 'bin', 'servo'))
            # Note that in the context of Homebrew, libexec is reserved for private use by the formula
            # and therefore is not symlinked into HOMEBREW_PREFIX.
            os.makedirs(path.join(dir_to_brew, 'libexec'))
            copy_dependencies(path.join(dir_to_brew, 'bin', 'servo'), path.join(dir_to_brew, 'libexec'))
            archive_deterministically(dir_to_brew, tar_path, prepend_path='servo/')
            delete(dir_to_brew)
            print("Packaged Servo into " + tar_path)
        elif is_windows():
            dir_to_msi = path.join(target_dir, 'msi')
            if path.exists(dir_to_msi):
                print("Cleaning up from previous packaging")
                delete(dir_to_msi)
            os.makedirs(dir_to_msi)

            print("Copying files")
            dir_to_temp = path.join(dir_to_msi, 'temp')
            dir_to_resources = path.join(dir_to_temp, 'resources')
            shutil.copytree(path.join(dir_to_root, 'resources'), dir_to_resources)
            shutil.copy(binary_path, dir_to_temp)
            copy_windows_dependencies(target_dir, dir_to_temp)

            change_prefs(dir_to_resources, "windows")

            # generate Servo.wxs
            import mako.template
            template_path = path.join(dir_to_root, "support", "windows", "Servo.wxs.mako")
            template = mako.template.Template(open(template_path).read())
            wxs_path = path.join(dir_to_msi, "Installer.wxs")
            open(wxs_path, "w").write(template.render(
                exe_path=target_dir,
                dir_to_temp=dir_to_temp,
                resources_path=dir_to_resources))

            # run candle and light
            print("Creating MSI")
            try:
                with cd(dir_to_msi):
                    subprocess.check_call(['candle', wxs_path])
            except subprocess.CalledProcessError as e:
                print("WiX candle exited with return value %d" % e.returncode)
                return e.returncode
            try:
                wxsobj_path = "{}.wixobj".format(path.splitext(wxs_path)[0])
                with cd(dir_to_msi):
                    subprocess.check_call(['light', wxsobj_path])
            except subprocess.CalledProcessError as e:
                print("WiX light exited with return value %d" % e.returncode)
                return e.returncode
            dir_to_installer = path.join(dir_to_msi, "Installer.msi")
            print("Packaged Servo into " + dir_to_installer)

            # Generate bundle with Servo installer.
            print("Creating bundle")
            shutil.copy(path.join(dir_to_root, 'support', 'windows', 'Servo.wxs'), dir_to_msi)
            bundle_wxs_path = path.join(dir_to_msi, 'Servo.wxs')
            try:
                with cd(dir_to_msi):
                    subprocess.check_call(['candle', bundle_wxs_path, '-ext', 'WixBalExtension'])
            except subprocess.CalledProcessError as e:
                print("WiX candle exited with return value %d" % e.returncode)
                return e.returncode
            try:
                wxsobj_path = "{}.wixobj".format(path.splitext(bundle_wxs_path)[0])
                with cd(dir_to_msi):
                    subprocess.check_call(['light', wxsobj_path, '-ext', 'WixBalExtension'])
            except subprocess.CalledProcessError as e:
                print("WiX light exited with return value %d" % e.returncode)
                return e.returncode
            print("Packaged Servo into " + path.join(dir_to_msi, "Servo.exe"))

            print("Creating ZIP")
            zip_path = path.join(dir_to_msi, "Servo.zip")
            archive_deterministically(dir_to_temp, zip_path, prepend_path='servo/')
            print("Packaged Servo into " + zip_path)

            print("Cleaning up")
            delete(dir_to_temp)
            delete(dir_to_installer)
        else:
            dir_to_temp = path.join(target_dir, 'packaging-temp')
            if path.exists(dir_to_temp):
                # TODO(aneeshusa): lock dir_to_temp to prevent simultaneous builds
                print("Cleaning up from previous packaging")
                delete(dir_to_temp)

            print("Copying files")
            dir_to_resources = path.join(dir_to_temp, 'resources')
            shutil.copytree(path.join(dir_to_root, 'resources'), dir_to_resources)
            shutil.copy(binary_path, dir_to_temp)

            change_prefs(dir_to_resources, "linux")

            print("Creating tarball")
            tar_path = path.join(target_dir, 'servo-tech-demo.tar.gz')

            archive_deterministically(dir_to_temp, tar_path, prepend_path='servo/')

            print("Cleaning up")
            delete(dir_to_temp)
            print("Packaged Servo into " + tar_path)

    @Command('install',
             description='Install Servo (currently, Android and Windows only)',
             category='package')
    @CommandArgument('--release', '-r', action='store_true',
                     help='Install the release build')
    @CommandArgument('--dev', '-d', action='store_true',
                     help='Install the dev build')
    @CommandArgument('--android',
                     action='store_true',
                     help='Install on Android')
    @CommandArgument('--magicleap',
                     default=None,
                     action='store_true',
                     help='Install on Magic Leap')
    @CommandArgument('--emulator',
                     action='store_true',
                     help='For Android, install to the only emulated device')
    @CommandArgument('--usb',
                     action='store_true',
                     help='For Android, install to the only USB device')
    @CommandArgument('--target', '-t',
                     default=None,
                     help='Install the given target platform')
    def install(self, release=False, dev=False, android=False, magicleap=False, emulator=False, usb=False, target=None):
        if target and android:
            print("Please specify either --target or --android.")
            sys.exit(1)
        if not android:
            android = self.handle_android_target(target)
        if target and magicleap:
            print("Please specify either --target or --magicleap.")
            sys.exit(1)
        if magicleap:
            target = "aarch64-linux-android"
        env = self.build_env(target=target)
        try:
            binary_path = self.get_binary_path(release, dev, android=android, magicleap=magicleap)
        except BuildNotFound:
            print("Servo build not found. Building servo...")
            result = Registrar.dispatch(
                "build", context=self.context, release=release, dev=dev, android=android, magicleap=magicleap,
            )
            if result:
                return result
            try:
                binary_path = self.get_binary_path(release, dev, android=android, magicleap=magicleap)
            except BuildNotFound:
                print("Rebuilding Servo did not solve the missing build problem.")
                return 1

        if magicleap:
            if not env.get("MAGICLEAP_SDK"):
                raise Exception("Magic Leap installs need the MAGICLEAP_SDK environment variable")
            mldb = path.join(env.get("MAGICLEAP_SDK"), "tools", "mldb", "mldb")
            pkg_path = path.join(path.dirname(binary_path), "Servo.mpk")
            exec_command = [
                mldb,
                "install", "-u",
                pkg_path,
            ]
        elif android:
            pkg_path = self.get_apk_path(release)
            exec_command = [self.android_adb_path(env)]
            if emulator and usb:
                print("Cannot install to both emulator and USB at the same time.")
                return 1
            if emulator:
                exec_command += ["-e"]
            if usb:
                exec_command += ["-d"]
            exec_command += ["install", "-r", pkg_path]
        elif is_windows():
            pkg_path = path.join(path.dirname(binary_path), 'msi', 'Servo.msi')
            exec_command = ["msiexec", "/i", pkg_path]

        if not path.exists(pkg_path):
            print("Servo package not found. Packaging servo...")
            result = Registrar.dispatch(
                "package", context=self.context, release=release, dev=dev, android=android, magicleap=magicleap,
            )
            if result != 0:
                return result

        print(" ".join(exec_command))
        return subprocess.call(exec_command, env=env)

    @Command('upload-nightly',
             description='Upload Servo nightly to S3',
             category='package')
    @CommandArgument('platform',
                     choices=PACKAGES.keys(),
                     help='Package platform type to upload')
    @CommandArgument('--secret-from-taskcluster',
                     action='store_true',
                     help='Retrieve the appropriate secrets from taskcluster.')
    def upload_nightly(self, platform, secret_from_taskcluster):
        import boto3

        def get_taskcluster_secret(name):
            url = (
                os.environ.get("TASKCLUSTER_PROXY_URL", "http://taskcluster") +
                "/secrets/v1/secret/project/servo/" +
                name
            )
            return json.load(urllib.urlopen(url))["secret"]

        def get_s3_secret():
            aws_access_key = None
            aws_secret_access_key = None
            if secret_from_taskcluster:
                secret = get_taskcluster_secret("s3-upload-credentials")
                aws_access_key = secret["aws_access_key_id"]
                aws_secret_access_key = secret["aws_secret_access_key"]
            return (aws_access_key, aws_secret_access_key)

        def nightly_filename(package, timestamp):
            return '{}-{}'.format(
                timestamp.isoformat() + 'Z',  # The `Z` denotes UTC
                path.basename(package)
            )

        def upload_to_s3(platform, package, timestamp):
            (aws_access_key, aws_secret_access_key) = get_s3_secret()
            s3 = boto3.client(
                's3',
                aws_access_key_id=aws_access_key,
                aws_secret_access_key=aws_secret_access_key
            )
            BUCKET = 'servo-builds'

            nightly_dir = 'nightly/{}'.format(platform)
            filename = nightly_filename(package, timestamp)
            package_upload_key = '{}/{}'.format(nightly_dir, filename)
            extension = path.basename(package).partition('.')[2]
            latest_upload_key = '{}/servo-latest.{}'.format(nightly_dir, extension)

            s3.upload_file(package, BUCKET, package_upload_key)
            copy_source = {
                'Bucket': BUCKET,
                'Key': package_upload_key,
            }
            s3.copy(copy_source, BUCKET, latest_upload_key)

        def update_maven(directory):
            (aws_access_key, aws_secret_access_key) = get_s3_secret()
            s3 = boto3.client(
                's3',
                aws_access_key_id=aws_access_key,
                aws_secret_access_key=aws_secret_access_key
            )
            BUCKET = 'servo-builds'

            nightly_dir = 'nightly/maven'
            dest_key_base = directory.replace("target/android/gradle/servoview/maven", nightly_dir)
            if dest_key_base[-1] == '/':
                dest_key_base = dest_key_base[:-1]

            # Given a directory with subdirectories like 0.0.1.20181005.caa4d190af...
            for artifact_dir in os.listdir(directory):
                base_dir = os.path.join(directory, artifact_dir)
                if not os.path.isdir(base_dir):
                    continue
                package_upload_base = "{}/{}".format(dest_key_base, artifact_dir)
                # Upload all of the files inside the subdirectory.
                for f in os.listdir(base_dir):
                    file_upload_key = "{}/{}".format(package_upload_base, f)
                    print("Uploading %s to %s" % (os.path.join(base_dir, f), file_upload_key))
                    s3.upload_file(os.path.join(base_dir, f), BUCKET, file_upload_key)

        def update_brew(package, timestamp):
            print("Updating brew formula")

            package_url = 'https://download.servo.org/nightly/macbrew/{}'.format(
                nightly_filename(package, timestamp)
            )
            with open(package) as p:
                digest = hashlib.sha256(p.read()).hexdigest()

            brew_version = timestamp.strftime('%Y.%m.%d')

            with TemporaryDirectory(prefix='homebrew-servo') as tmp_dir:
                def call_git(cmd, **kwargs):
                    subprocess.check_call(
                        ['git', '-C', tmp_dir] + cmd,
                        **kwargs
                    )

                call_git([
                    'clone',
                    'https://github.com/servo/homebrew-servo.git',
                    '.',
                ])

                script_dir = path.dirname(path.realpath(__file__))
                with open(path.join(script_dir, 'servo-binary-formula.rb.in')) as f:
                    formula = f.read()
                formula = formula.replace('PACKAGEURL', package_url)
                formula = formula.replace('SHA', digest)
                formula = formula.replace('VERSION', brew_version)
                with open(path.join(tmp_dir, 'Formula', 'servo-bin.rb'), 'w') as f:
                    f.write(formula)

                call_git(['add', path.join('.', 'Formula', 'servo-bin.rb')])
                call_git([
                    '-c', 'user.name=Tom Servo',
                    '-c', 'user.email=servo@servo.org',
                    'commit',
                    '--message=Version Bump: {}'.format(brew_version),
                ])

                if secret_from_taskcluster:
                    token = get_taskcluster_secret('github-homebrew-token')["token"]
                else:
                    token = os.environ['GITHUB_HOMEBREW_TOKEN']

                push_url = 'https://{}@github.com/servo/homebrew-servo.git'
                # TODO(aneeshusa): Use subprocess.DEVNULL with Python 3.3+
                with open(os.devnull, 'wb') as DEVNULL:
                    call_git([
                        'push',
                        '-qf',
                        push_url.format(token),
                        'master',
                    ], stdout=DEVNULL, stderr=DEVNULL)

        timestamp = datetime.utcnow().replace(microsecond=0)
        for package in PACKAGES[platform]:
            if path.isdir(package):
                continue
            if not path.isfile(package):
                print("Could not find package for {} at {}".format(
                    platform,
                    package
                ), file=sys.stderr)
                return 1
            upload_to_s3(platform, package, timestamp)

        if platform == 'maven':
            for package in PACKAGES[platform]:
                update_maven(package)

        if platform == 'macbrew':
            packages = PACKAGES[platform]
            assert(len(packages) == 1)
            update_brew(packages[0], timestamp)

        return 0