scripts/preview_docs

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# Copyright 2018 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""A script for previewing rendering of docs in Gitiles."""

from __future__ import print_function

import argparse
import logging
import os
import shutil
import subprocess
import sys
import tempfile
import webbrowser

SCRIPT_NAME = 'preview_docs'
COMMIT_MSG = 'Preview files\n\nCreated by %s.' % SCRIPT_NAME

REMOTE_NAMES = ('cros', 'cros-internal', 'origin')
GERRIT_URL_FRAGMENT = '-review.googlesource.com'
GITILES_URL_FRAGMENT = '.googlesource.com'


def die(msg, *args):
    """Log the given message and exit."""
    logging.fatal(msg, *args)
    sys.exit(1)


def git(*args):
    """Run git with given arguments, returning the output."""
    logging.debug('git %r', args)
    output = subprocess.check_output(('git',) + args, encoding='utf-8').strip()
    if output:
        logging.debug('> %s', output)
    return output


def main(argv):
    parser = argparse.ArgumentParser(description=__doc__)
    parser.add_argument('file', nargs='+')
    parser.add_argument('--verbose', action='store_true')
    opts = parser.parse_args(argv)

    # Configure logging.
    log_level = logging.INFO
    if opts.verbose:
        log_level = logging.DEBUG
    logging.basicConfig(level=log_level)
    logging.root.name = SCRIPT_NAME

    # Get USER.
    user = os.environ.get('USER')
    if not user or user == 'root':
        die('Need a non-root USER in the environment.')

    # Get the current subdirectory within the git repo.
    git_prefix = git('rev-parse', '--show-prefix')

    # Get/transform remote URL.
    remote_url = None
    for remote_name in REMOTE_NAMES:
        try:
            remote_url = git('remote', 'get-url', '--push', remote_name)
            if (GITILES_URL_FRAGMENT in remote_url or
                    GERRIT_URL_FRAGMENT in remote_url):
                break
        except subprocess.CalledProcessError:
            # The remote name isn't configured (probably).
            pass
    else:
        die("Couldn't find a remote that looks like a Gitiles URL.")

    temp_dir = tempfile.mkdtemp(SCRIPT_NAME)
    try:
        # Avoid mucking around with the user's actual index.
        os.environ['GIT_INDEX_FILE'] = os.path.join(temp_dir, 'index')

        files = list(opts.file)

        # Include /navbar.md if present.
        git_root = git('rev-parse', '--show-cdup')
        navbar_path = os.path.join(git_root, 'navbar.md')
        if os.path.isfile(navbar_path):
            files.append(navbar_path)

        # Create a commit with just the target files.
        git('add', '--', *files)
        tree = git('write-tree')
        commit = git('commit-tree', '-m', COMMIT_MSG, tree)

        # Push the commit to a specific user-scoped sandbox ref.
        git('push', '-f', '--no-verify', remote_url,
            '%s:refs/sandbox/%s/%s' % (commit, user, SCRIPT_NAME))

        # Build the preview URL.
        gitiles_url = remote_url.replace(GERRIT_URL_FRAGMENT,
                                         GITILES_URL_FRAGMENT, 1)
        gitiles_url += '/+/%s/%s' % (commit, git_prefix)
        if len(opts.file) == 1:
            gitiles_url += opts.file[0]
        print('Preview URL:', gitiles_url)

        # Attempt to open in a browser.
        try:
            webbrowser.open(gitiles_url)
        except webbrowser.Error:
            # Opening the browser is optional and could fail for many reasons.
            pass

    finally:
        shutil.rmtree(temp_dir)


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))