Mini Shell

# -*- coding: utf-8 -*-

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2018 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT
#

import os
import shutil
import subprocess
import simplejson as json
import configparser

CL_CONFIG = '/etc/sysconfig/cloudlinux'
HOOK_SECTION = 'hooks'
HOOK_SEPARATOR = ';'

DEBUG_STRING = 'python-cllib:clhook:'


def get_config(file_name):
    """
    read config from file_name
    return config
    """
    config = configparser.ConfigParser(interpolation=None, strict=False)
    config.optionxform = str  # make config case sensitive
    config.read(file_name)
    return config


def write_config(config, file_name, debug_local_name):
    """
    write config to file_name
    return [BOOLEAN_STATE, MESSAGE]
    """
    try:
        tmp_cfg_path = f'{file_name}.{os.getpid()}'
        with open(tmp_cfg_path, 'w', encoding='utf-8') as tmpconfig:
            config.write(tmpconfig)
        shutil.move(tmp_cfg_path, file_name)
    except IOError as e:
        return [False, f'{debug_local_name}{file_name} write error\n{str(e)}']
    return [True, 'OK\n']


def get_hook_list_from_file(hook_prefix, config_file = CL_CONFIG):
    """
    return [BOOLEAN_STATE, hook_list]
    """
    hook_list = []
    config = get_config(config_file)
    try:
        hook_list = config.get(HOOK_SECTION, hook_prefix).split(HOOK_SEPARATOR)
    except (configparser.NoOptionError, configparser.NoSectionError):
        return [False, hook_list]
    return [True, hook_list]


def register_hook(hook_path, hook_prefix, config_file = CL_CONFIG):
    """
    add hook to config file
    return [BOOLEAN_STATE, MESSAGE]
    """
    debug_local_name = DEBUG_STRING + 'register_hook:'
    config = get_config(config_file)
    try:
        hook_list = config.get(HOOK_SECTION, hook_prefix).split(HOOK_SEPARATOR)
        if hook_path in hook_list:
            return [True, debug_local_name + 'Hook ' + str(hook_path) + ' already registred\n' ]
        hook_list.append(hook_path)
        config.set(HOOK_SECTION, hook_prefix, HOOK_SEPARATOR.join(hook_list))
    except configparser.NoSectionError:
        config.add_section(HOOK_SECTION)
        config.set(HOOK_SECTION, hook_prefix, hook_path)
    except configparser.NoOptionError:
        config.set(HOOK_SECTION, hook_prefix, hook_path)
    return write_config(config, config_file, debug_local_name)


def unregister_hook(hook_path, hook_prefix, config_file = CL_CONFIG):
    """
    remove hook from config_file
    return [BOOLEAN_STATE, MESSAGE]
    """
    debug_local_name = DEBUG_STRING + 'unregister_hook:'
    config = get_config(config_file)
    try:
        hook_list = config.get(HOOK_SECTION, hook_prefix).split(HOOK_SEPARATOR)
        hook_list.remove(hook_path)
        config.set(HOOK_SECTION, hook_prefix, HOOK_SEPARATOR.join(hook_list))
        return write_config(config, config_file, debug_local_name)
    except (configparser.NoSectionError, configparser.NoOptionError, ValueError):
        return [True, 'OK\n']


def call_hook_list(hook_list, data):
    """
    call hooks and send data as json to stdin
    return [BOOLEAN_STATUS, message]
    """
    debug_local_name = DEBUG_STRING + 'call_hook:'
    json_encode = json.dumps(data)
    for hook in hook_list:
        if os.path.isfile(hook) and os.access(hook, os.X_OK):
            try:
                with subprocess.Popen(
                    hook,
                    stdin=subprocess.PIPE,
                    stdout=subprocess.PIPE,
                    stderr=subprocess.PIPE,
                ) as proc:
                    proc.stdin.write(json_encode)
                    proc.communicate()
            except OSError:
                return [False, debug_local_name + 'Hook call error\n']
        else:
            return [False, debug_local_name + str(hook) + ' : isn`t file or isn`t runnable\n']
    return [True, 'OK\n']