Mini Shell

#!/usr/bin/python

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()
    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 = file_name + '.' + str(os.getpid())
        tmpconfig = open(tmp_cfg_path,'w')
        config.write(tmpconfig)
        tmpconfig.close()
        shutil.move(tmp_cfg_path, file_name)
    except IOError:
        return [False, debug_local_name + str(file_name) + ' write error\n']
    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:'
    hook_list = []
    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:
                pipe = subprocess.Popen(hook, stdin=subprocess.PIPE, stdout = subprocess.PIPE, stderr=subprocess.PIPE)
                pipe.stdin.write(json_encode)
                pipe.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']