Source code for darc.proxy.zeronet

# -*- coding: utf-8 -*-
"""ZeroNet Proxy
====================

The :mod:`darc.proxy.zeronet` module contains the auxiliary functions
around managing and processing the ZeroNet proxy.

"""

import os
import pprint
import shlex
import shutil
import subprocess  # nosec
import sys
import traceback
import warnings

import stem.util.term

from darc.const import DEBUG, VERBOSE
from darc.error import ZeroNetBootstrapFailed, render_error
from darc.proxy.tor import tor_bootstrap

# ZeroNet args
ZERONET_ARGS = shlex.split(os.getenv('ZERONET_ARGS', ''))

# bootstrap wait
BS_WAIT = float(os.getenv('ZERONET_WAIT', '90'))

# ZeroNet port
ZERONET_PORT = os.getenv('ZERONET_PORT', '43110')

# ZeroNet bootstrap retry
ZERONET_RETRY = int(os.getenv('ZERONET_RETRY', '3'))

# ZeroNet project path
ZERONET_PATH = os.getenv('ZERONET_PATH', '/usr/local/src/zeronet')

# manage ZeroNet through darc?
_MNG_ZERONET = bool(int(os.getenv('DARC_ZERONET', '1')))

# ZeroNet bootstrapped flag
_ZERONET_BS_FLAG = not _MNG_ZERONET
# ZeroNet daemon process
_ZERONET_PROC = None
# ZeroNet bootstrap args
_ZERONET_ARGS = [os.path.join(ZERONET_PATH, 'ZeroNet.sh'), 'main']
_ZERONET_ARGS.extend(ZERONET_ARGS)

if DEBUG:
    print(stem.util.term.format('-*- ZERONET PROXY -*-',
                                stem.util.term.Color.MAGENTA))  # pylint: disable=no-member
    print(render_error(pprint.pformat(_ZERONET_ARGS), stem.util.term.Color.MAGENTA))  # pylint: disable=no-member
    print(stem.util.term.format('-' * shutil.get_terminal_size().columns,
                                stem.util.term.Color.MAGENTA))  # pylint: disable=no-member


def _zeronet_bootstrap():
    """ZeroNet bootstrap.

    The bootstrap arguments are defined as :data:`~darc.proxy.zeronet._ZERONET_ARGS`.

    Raises:
        subprocess.CalledProcessError: If the return code of :data:`~darc.proxy.zeronet._ZERONET_PROC` is non-zero.

    See Also:
        * :func:`darc.proxy.zeronet.zeronet_bootstrap`
        * :data:`darc.proxy.zeronet.BS_WAIT`
        * :data:`darc.proxy.zeronet._ZERONET_BS_FLAG`
        * :data:`darc.proxy.zeronet._ZERONET_PROC`

    """
    global _ZERONET_BS_FLAG, _ZERONET_PROC  # pylint: disable=global-statement

    # launch Tor first
    tor_bootstrap()

    # launch ZeroNet process
    _ZERONET_PROC = subprocess.Popen(  # nosec
        _ZERONET_ARGS, stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.STDOUT,
    )

    try:
        stdout, stderr = _ZERONET_PROC.communicate(timeout=BS_WAIT)
    except subprocess.TimeoutExpired as error:
        stdout, stderr = error.stdout, error.stderr
    if VERBOSE:
        if stdout is not None:
            print(render_error(stdout, stem.util.term.Color.BLUE))  # pylint: disable=no-member
    if stderr is not None:
        print(render_error(stderr, stem.util.term.Color.RED))  # pylint: disable=no-member

    returncode = _ZERONET_PROC.returncode
    if returncode is not None and returncode != 0:
        raise subprocess.CalledProcessError(returncode, _ZERONET_ARGS,
                                            _ZERONET_PROC.stdout,
                                            _ZERONET_PROC.stderr)

    # update flag
    _ZERONET_BS_FLAG = True


def zeronet_bootstrap():
    """Bootstrap wrapper for ZeroNet.

    The function will bootstrap the ZeroNet proxy. It will retry for
    :data:`~darc.proxy.zeronet.ZERONET_RETRY` times in case of failure.

    Also, it will **NOT** re-bootstrap the proxy as is guaranteed by
    :data:`~darc.proxy.zeronet._ZERONET_BS_FLAG`.

    Warns:
        ZeroNetBootstrapFailed: If failed to bootstrap ZeroNet proxy.

    Raises:
        :exc:`UnsupportedPlatform`: If the system is not supported, i.e. not macOS or Linux.

    See Also:
        * :func:`darc.proxy.zeronet._zeronet_bootstrap`
        * :data:`darc.proxy.zeronet.ZERONET_RETRY`
        * :data:`darc.proxy.zeronet._ZERONET_BS_FLAG`

    """
    # don't re-bootstrap
    if _ZERONET_BS_FLAG:
        return

    print(stem.util.term.format('-*- ZeroNet Bootstrap -*-',
                                stem.util.term.Color.MAGENTA))  # pylint: disable=no-member
    for _ in range(ZERONET_RETRY+1):
        try:
            _zeronet_bootstrap()
            break
        except Exception as error:
            if DEBUG:
                message = '[Error bootstraping ZeroNet proxy]' + os.linesep + traceback.format_exc()
                print(render_error(message, stem.util.term.Color.RED), end='', file=sys.stderr)  # pylint: disable=no-member

            warning = warnings.formatwarning(error, ZeroNetBootstrapFailed, __file__, 133, 'zeronet_bootstrap()')
            print(render_error(warning, stem.util.term.Color.YELLOW), end='', file=sys.stderr)  # pylint: disable=no-member
    print(stem.util.term.format('-' * shutil.get_terminal_size().columns,
                                stem.util.term.Color.MAGENTA))  # pylint: disable=no-member