libdot/bin/node

#!/usr/bin/env python3
# Copyright 2019 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Run node with the right settings."""

import os
import platform
import shutil
import sys

import libdot


# Bucket maintained by us.
NODE_MODULES_GS_FRAGMENT = "chromeos-localmirror/secureshell/distfiles"
NODE_MODULES_GS_URI = f"gs://{NODE_MODULES_GS_FRAGMENT}"

# The node_modules & node paths.
NODE_MODULES_DIR = libdot.LIBAPPS_DIR / "node_modules"
NODE_BIN_DIR = NODE_MODULES_DIR / ".bin"
NODE = NODE_BIN_DIR / "node"
# Use a dotdir as npm expects to manage everything under node_modules/.
NODE_DIR = NODE_MODULES_DIR / ".node"


def run(cmd, **kwargs):
    """Run the node |cmd|.

    This assumes |cmd| is a node program.  Different OS's might need to invoke
    node differently, so wrap the calls here.
    """
    extra_env = kwargs.setdefault("extra_env", {})

    # We need the node bin dir to be at the start of the $PATH as some packages
    # will try to run other npm packages directly.
    assert "PATH" not in extra_env
    extra_env["PATH"] = os.pathsep.join((str(NODE_BIN_DIR), os.getenv("PATH")))

    # We'll manage this ourselves to keep node_modules size small.
    extra_env["PUPPETEER_SKIP_DOWNLOAD"] = "true"

    return libdot.run(
        cmd[1:],
        cmd_prefix=[NODE, NODE_BIN_DIR / cmd[0]],
        log_prefix=[cmd[0]],
        **kwargs,
    )


def update():
    """Download & update our copy of node."""
    osname = platform.system()
    if osname == "Linux":
        item = "node/linux"
    elif osname == "Darwin":
        item = "node/mac"
    elif osname == "Windows":
        item = "node/win"
    else:
        raise RuntimeError(f"Unknown OS {osname}")

    # In case of an upgrade, nuke existing dir.
    spec = libdot.fetch_manifest_lookup(libdot.DIR / "fetch.json", item)
    hash_file = NODE_DIR / spec.hashes["sha256"]
    if not hash_file.exists():
        shutil.rmtree(NODE_DIR, ignore_errors=True)

    node = NODE
    if osname == "Windows":
        node = node.with_suffix(".exe")
    if not node.exists():
        os.makedirs(NODE_BIN_DIR, exist_ok=True)
        os.makedirs(NODE_DIR, exist_ok=True)

        # Download & unpack the archive.
        output = NODE_DIR / "node.tmp"
        libdot.fetch_manifest_spec(spec, output)
        if osname == "Windows":
            libdot.unlink(node)
            output.rename(node)
        else:
            libdot.unpack(output, cwd=NODE_DIR)
            libdot.unlink(output)

            # Create canonical symlinks for node.
            path = next(NODE_DIR.glob("*/bin/node"))
            libdot.symlink(path, NODE)

        # Mark the hash of this checkout.
        libdot.touch(hash_file)


def modules_update():
    """Download & update our copy of node_modules."""
    libdot.download_tarball_manifest(
        libdot.DIR / "fetch.json",
        "node/modules",
        NODE_MODULES_DIR,
    )


def main(argv):
    """The main func!"""
    libdot.setup_logging()
    libdot.node_and_npm_setup()
    os.execv(NODE, ["node"] + argv)


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