scripts/preview_docs

#!/usr/bin/env python3
# Copyright 2018 The ChromiumOS Authors
# 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."""

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:]))