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[EDIT] FILE: apps_manager.py

# coding=utf-8

# Copyright © Cloud Linux GmbH & Cloud Linux Software, Inc 2010-2019 All Rights Reserved
#
# Licensed under CLOUD LINUX LICENSE AGREEMENT
# http://cloudlinux.com/docs/LICENSE.TXT

from __future__ import absolute_import
from __future__ import print_function
from __future__ import division
import json
import os
import pwd as _stdpwd
import re
import stat
from abc import ABCMeta, abstractmethod
from datetime import datetime

import clselect.clpassenger as clpassenger
import secureio
from future.utils import iteritems
from past.builtins import unicode

from clcommon import ClPwd
from clcommon.utils import get_file_lines, write_file_lines
from clselect.utils import pretty_json, delete_using_realpath_keys, get_abs_rel
from clselect import ClSelectExcept
from clselect.baseclselect import (
    BaseSelectorError,
    AbsentFileError,
    MissingVirtualenvError,
    MissingAppRootError
)
from .selector_manager import BaseSelectorManager  # NOQA
from clselect.utils import file_readlines, file_writelines
from clselect.utils import get_using_realpath_keys
from future.utils import with_metaclass

class BaseApplicationsManager(with_metaclass(ABCMeta, object)):
    """
    Base class that responsible for gathering and set information about applications.
    """

# needs to be overridden in child class
    _USER_CONFIG = None
    _LOG_FILE_NAME = '/var/log/selectorctl.log'
    INTERPRETER = None
    VENV_DIR = None
    BINARY_NAME = None

def __init__(self, manager):
        self._manager = manager  # type: BaseSelectorManager
        self._pwd = ClPwd()

@classmethod
    def write_string_to_log(cls, log_str):
        """
        Writes string to log file
        :param log_str: String to write
        :return: None
        """
        try:
            dt_string = datetime.now().strftime("%Y-%m-%d %H:%M:%S")
            write_file_lines(cls._LOG_FILE_NAME, ['%s: %s\n' % (dt_string, log_str)], 'a')
        except (IOError, OSError):
            pass

def add_app_to_config(self, user, app_directory, app_data):
        """
        Add data to user's config (update info for an app with app_directory specified)
        :param str user: name of unix user
        :param str app_directory: Application root directory
        :param dict app_data: Application data
        :return: None
        """
        current_dict = self.get_user_config_data(user)
        current_dict[app_directory] = app_data
        # Write new config to file
        self.write_full_user_config_data(user, current_dict)

def add_env_vars_for_htaccess(self, user_name, app_directory, env_vars, doc_root):
        """
        Add enviroment variables to .htaccess file for LVEMAN-1623
        :param str user_name: Name of unix user
        :param str app_directory: Application root directory
        :param dict env_vars: Dict of enviroment variables
        :param str doc_root: doc root of application
        :return: None
        """
        env_section_begin = "# DO NOT REMOVE OR MODIFY. CLOUDLINUX ENV VARS CONFIGURATION BEGIN"
        env_section_end = "# DO NOT REMOVE OR MODIFY. CLOUDLINUX ENV VARS CONFIGURATION END"
        htaccess_file = self.get_htaccess_by_appdir(user_name, app_directory, doc_root, None)
        if htaccess_file is None:
            return
        with open(htaccess_file, "r", errors='surrogateescape') as htaccess:
            lines = [line for line in htaccess.read().split('\n') if line]
            if env_section_begin in lines and env_section_end in lines:
                start = lines.index(env_section_begin)
                end = lines.index(env_section_end)
                del lines[start: end + 1]
            if env_vars is not None:
                lines.append(env_section_begin)
                lines.append("<IfModule Litespeed>")
                for env_var, value in env_vars.items():
                    env_var = env_var.replace('\r', '').replace('\n', '')
                    value = value.replace('\r', '').replace('\n', '')
                    lines.append("SetEnv {0} {1}".format(env_var, value))
                lines.append("</IfModule>")
                lines.append(env_section_end)
        with open(htaccess_file, "w", errors='surrogateescape') as htaccess:
            htaccess.write('\n'.join(lines))

def remove_app_from_config(self, user, app_dir):
        """
        Removes application from config
        :param user: User name
        :param app_dir: Application directory
        :return: True if app is exists in config,
        False - if app is not exists in config
        """
        config_data = self.get_user_config_data(user)
        try:
            delete_using_realpath_keys(user, app_dir, config_data)
            # write new config
            self.write_full_user_config_data(user, config_data)
        except KeyError:
            return False
        else:
            return True

def replace_domain_in_configs(self, username, domain, new_domain, include_subdomains=False):
        """
        Replace domain in config files when it is renamed.
        :param username: domain owner
        :param domain: previous name
        :param new_domain: name after rename
        :param include_subdomains: whether we should also rename subdomains
        :return:
        """
        full_config = self.get_user_config_data(username)
        if not full_config:
            return

# find application with domain
        for app, config in iteritems(full_config):
            if include_subdomains:
                match = re.search(r'(\.|^)%s$' % domain, config['domain'])
            else:
                match = re.search(r'^%s$' % domain, config['domain'])

if match is not None:
                config['domain'] = unicode('{}{}'.format(
                    # Cut out old_domain
                    config['domain'][:-len(domain)],
                    new_domain))
        self.write_full_user_config_data(username, full_config)

@staticmethod
    def _find_config_files(user_name, app_directory, patterns=None):
        """
        Return list of detected config files
        """

abs_path, rel_path = get_abs_rel(user_name, app_directory)
        return [config for config in patterns if os.path.exists(os.path.join(abs_path, config))]

def update_htaccess_file(self, user_name, app_root, doc_root):
        """
        Creates .htaccess file for application based on application config data
        :param str user_name: User's name
        :param str app_root: Application root
        :param doc_root: Document root for the domain
        :return: None
        """
        # NOT A SECURITY BOUNDARY — see the longer rationale in
        # commons/lib/clselect/clpassenger.py (configure, htaccess_needs_update
        # block). Same shape: this re-renders the user's own ~/.htaccess from
        # their stored app config. The user already has direct write access
        # to that file, so injecting unusual Passenger* directives via
        # app_config values gains nothing they couldn't write by hand;
        # Apache's AllowOverride is the actual gate. Do NOT add input
        # validation to defend against directive injection here — the only
        # outcome would be rejecting filesystem-path-shaped values that
        # legitimately contain backslash or quote characters.
        app_config = self.get_app_config(user_name, app_root)
        user_dir = self._pwd.get_homedir(user_name)
        htaccess_file = self.get_htaccess_by_appdir(user_name, app_root, doc_root, app_config)
        new_lines = [
            '{}\n'.format(clpassenger.HTACCESS_BEGIN),
            'PassengerAppRoot "{}"\n'.format(os.path.join(user_dir, app_root)),
            'PassengerBaseURI "/{}"\n'.format(app_config['app_uri']),
        ]
        new_lines.extend(self.get_interpreter_specific_passenger_lines(
            self.get_binary_path(user_name, app_root, user_dir),
            app_config))
        passenger_log_file = app_config.get('passenger_log_file', None)
        if passenger_log_file:
            new_lines.append('PassengerAppLogFile "%s"\n' % passenger_log_file)
        new_lines.append(clpassenger.HTACCESS_END + '\n')
        # Append all existing lines
        new_lines.extend(file_readlines(htaccess_file, errors='surrogateescape'))
        new_lines = clpassenger.rm_double_empty_lines(new_lines)
        # DiD (F-02, CLOS-5516): open the .htaccess destination with
        # O_NOFOLLOW so a symlink swap between the file_readlines above
        # and this write cannot divert the write to a file outside the
        # user's docroot. Refutation still holds — every caller drops to
        # the target user's uid before this method runs — but the
        # sink-side pin closes the symlink-write class at the boundary
        # itself.
        try:
            src_st = os.stat(htaccess_file, follow_symlinks=False)
            keep_mode = stat.S_IMODE(src_st.st_mode) if stat.S_ISREG(src_st.st_mode) else 0o644
        except FileNotFoundError:
            keep_mode = 0o644
        fd = os.open(htaccess_file,
                     os.O_WRONLY | os.O_CREAT | os.O_TRUNC
                     | os.O_NOFOLLOW | os.O_CLOEXEC,
                     keep_mode)
        with os.fdopen(fd, 'w', errors='surrogateescape') as f:
            f.writelines(new_lines)

@staticmethod
    @abstractmethod
    def get_interpreter_specific_passenger_lines(binary_path, app_config):
        """
        Return list of lines that needs to be added to htaccess and are
        specific to the interpreter
        """
        raise NotImplementedError

def get_binary_path(self, user, app_root, user_dir, binary_name=None):
        """
        Return a path to the environment's interpreter binary
        Get interpreter path for application
        :param user: owner of the application
        :param app_root: app path relative to user home (app-root)
        :param user_dir: User's home directory
        :param binary_name: name of binary in virtual environemnt (python, npm, node)
        :return: path to interpreter binary in virtual environment
        """
        version = self.get_interpreter_version_for_app(user, app_root)
        if binary_name is None:
            binary_name = self.BINARY_NAME
        return os.path.join(user_dir, self.VENV_DIR, app_root, version, 'bin', binary_name)

def get_users_dict(self, username=None):
        """
        Retrives info about user(s).
        :param str | None username: Username to retrive information.
        :return: Dictionary with user info. Example:
          {'user1': pw_struct}
        """
        if username is None:
            return self._pwd.get_user_dict()
        return {username: self._pwd.get_pw_by_name(username)}

def get_user_config_data(self, user):
        """
        Get all data from user's config
        :param user: name of unix user
        :return: json data from user's config as dictionary
        """
        _user_config_data = {}
        user_config = self._get_path_to_user_config(user)
        # user_config lives under the user's home directory; when this code runs
        # as root (e.g. utils/fix-nodejs-environments.py during RPM upgrade) the
        # user controls the path and could symlink it to a root-readable file.
        # Mirror the safe pattern from read_user_selector_config_json() in this
        # module: read via secureio.read_file_secure() under euid==0 so the
        # underlying open() runs as the target user (fork+seteuid).
        if os.path.isfile(user_config):
            if os.geteuid() == 0:
                user_pw = self._pwd.get_pw_by_name(user)
                secureio.SILENT_FLAG = True
                # exit_on_error=False makes read_file_secure return None
                # rather than calling sys.exit on read failure. The downstream
                # ''.join() would TypeError on None, so the empty-list fallback
                # below routes a read failure through the same WrongData path
                # the JSON-parse failure already used.
                data = secureio.read_file_secure(user_config, user_pw.pw_uid, user_pw.pw_gid,
                                                 exit_on_error=False, write_log=False)
            else:
                data = get_file_lines(user_config)
            try:
                _user_config_data = json.loads(''.join(data or []))
            except (ValueError, TypeError):
                raise ClSelectExcept.WrongData('User config "{}" is broken'.format(self._USER_CONFIG))
        return _user_config_data

def get_app_config(self, user, app_dir):
        """
        Retrieves full application config
        :param user: User name
        :param app_dir: Application directory
        :return: Application data as dictionary
            If None - No application data found in config
        """
        user_config_data = self.get_user_config_data(user)
        try:
            return get_using_realpath_keys(user, app_dir, user_config_data)
        except KeyError:
            return None

def get_app_domain(self, username, app_directory):
        """
        Retrieves domain for provided user's application
        :param username: user name
        :param app_directory: application root directory
        :return str: application domain
        """
        app_config = self.get_app_config(username, app_directory)
        return app_config['domain']

def get_app_uri(self, username, app_directory):
        """
        Retrieves uri for provided user's application
        :param username: user name
        :param app_directory: application root directory
        :return str: application uri
        """
        app_data = self.get_app_config(username, app_directory)
        return app_data['app_uri']

def get_app_startup_file(self, username, app_directory):
        """
        Retrieves name of startup file for provided user's application
        :param username: user name
        :param app_directory: application root directory
        :return str: name of startup file of application
        """
        app_data = self.get_app_config(username, app_directory)
        return app_data['startup_file']

def get_app_status(self, username, app_directory):
        """
        Retrieves status for provided user's app_directory
        :param username: user name
        :param app_directory: application root directory
        :return str: status of application
        """
        app_data = self.get_app_config(username, app_directory)
        return app_data['app_status']

def get_interpreter_version_for_app(self, username, app_directory):
        """
        Retrieves interpreter version for provided user and application
        :param username: user name
        :param app_directory: application root directory
        :return str: major interpreter version
        """
        app_data = self.get_app_config(username, app_directory)
        if app_data is None:
            raise ClSelectExcept.ConfigMissingError('Application config is missed '
                                                    'for user: {}'.format(username))
        return app_data['%s_version' % self.INTERPRETER]

def _get_path_to_user_config(self, username):
        """
        Get full path to user config ~/${_USER_CONFIG}
        :param username: name of unix user
        :return: full path to config
        """
        user_home = self._pwd.get_homedir(username)
        application_config = os.path.join(user_home, self._USER_CONFIG)

return application_config

def _get_full_version_for_short(self, major_version):
        """
        Retrieves full version for supplied major version.
        :return: str - Full version or None if full version not found
        """
        full_version = self._manager.pkg.get_full_version(major_version)
        if full_version != major_version:
            return full_version
        return None

def _add_single_user_app(self, users_data_dest_dict, user_pw_entry, app_root_dir, app_data):
        """
        Add single application data to user_data_dest_dict
        :param users_data_dest_dict: Destination dictionary with application data
        :param user_pw_entry: User's passwd entry
        :param app_root_dir: Application root directory
        :param app_data: Application data
        :return: None
        """
        if user_pw_entry.pw_name in users_data_dest_dict:
            # User already present in dict
            users_data_dest_dict[user_pw_entry.pw_name]["applications"][app_root_dir] = app_data
        else:
            # No such user in dict - add it
            user_data = {
                "homedir": user_pw_entry.pw_dir,
                "applications": {app_root_dir: app_data}
            }
            users_data_dest_dict[user_pw_entry.pw_name] = user_data

def _add_detected_config_files_to_application(self, app_data, app_root_dir, user_pw_entry):
        """Add automatically-detected config files to user-defined list"""
        config_files_detected = self._find_config_files(user_pw_entry.pw_name, app_root_dir)
        merged_files = set(app_data['config_files'] + config_files_detected)
        app_data['config_files'] = list(merged_files)

def _add_all_user_apps(self, user_pw_entry, user_data_dest_dict, user_app_data):
        """
        Add all user's apps information to user_data_dest_dict
        :param user_pw_entry: User's passwd entry
        :param user_data_dest_dict: Destination dictionary with application data
        :param user_app_data: User's application data ([node|python|ruby]-selector.json file content as dictionary).
        :return: None
        """
        version_key = '%s_version' % self.INTERPRETER
        for app_root_dir, app_data in iteritems(user_app_data):
            # The selector JSON is user-writable (perm 0644, owned by the
            # user). A malformed entry (e.g. `{"app": {}}` with no
            # `<INTERPRETER>_version` field, or a non-dict value) would
            # otherwise raise KeyError / TypeError mid-loop and abort the
            # bulk aggregation in get_applications_users_info() — taking
            # every other user's data down with it. Skip the entry instead.
            if not isinstance(app_data, dict) or version_key not in app_data:
                continue
            full_interpreter_version = self._get_full_version_for_short(app_data[version_key])
            if full_interpreter_version is None or full_interpreter_version not in user_data_dest_dict:
                # Application's interpreter version is absent in available versions of
                # interpreters - skip application
                continue
            # We added section `users` because version has at least one application
            if 'users' not in user_data_dest_dict[full_interpreter_version]:
                user_data_dest_dict[full_interpreter_version]['users'] = {}
            # Manually add venv path to config in order to display it in lvemanager
            app_data['virtualenv'] = {
                'activate_path': self.get_binary_path(
                    user_pw_entry.pw_name, app_root_dir, user_pw_entry.pw_dir,
                    binary_name='activate')
            }
            # we do not need this key (why?)
            del app_data[version_key]
            users_dict = user_data_dest_dict[full_interpreter_version]['users']
            self._add_detected_config_files_to_application(app_data, app_root_dir, user_pw_entry)
            self._add_single_user_app(users_dict, user_pw_entry, app_root_dir, app_data)

@staticmethod
    def _add_absent_passenger_log_file(user_config_dict):
        """
        Append absent 'passenger_log_file' key with None value to each application
        :param user_config_dict: Sourse dictionary to modify
        :return: Modified dict with 'passenger_log_file' keys
        """
        for app_root, app_data in iteritems(user_config_dict):
            if 'passenger_log_file' not in app_data:
                app_data['passenger_log_file'] = None
            user_config_dict[app_root] = app_data
        return user_config_dict

def read_user_selector_config_json(self, user_homedir, uid, gid, euid=None):
        """
        Read [python|ruby|node]-selector.json file from user's directory.
        :param euid: current effective uid
        :param user_homedir: user's home directory
        :param uid: uid for drop rights
        :param gid: gid for drop rights
        :return: Cortege contents_dict. None - there is no [python|ruby|node]-selector.json file in user's directory
        :raises BaseSelectorError if error. Exception contents:
                        {'message': "File %(file)s read/parse error: %(error)s",
                        'context': {'file': node_json_path, 'error': 'some message'}}
        """
        # don't do this like euid=os.geteuid() in method signature!
        if euid is None:
            euid = os.geteuid()

json_config_path = os.path.join(user_homedir, self._USER_CONFIG)
        if not os.path.exists(json_config_path):
            raise AbsentFileError(json_config_path)
        try:
            if euid == 0:
                # reads file with drop rights
                # to prevent print error messages from secureio.read_file_secure directly to stdout
                secureio.SILENT_FLAG = True
                file_lines = secureio.read_file_secure(json_config_path, uid, gid, exit_on_error=False, write_log=False)
            else:
                # read file without dropping rights
                file_lines = get_file_lines(json_config_path)
            return self._add_absent_passenger_log_file(json.loads(''.join(file_lines)))
        except (IOError, OSError, TypeError, ValueError) as e:
            # [python|node|ruby]-selector.json is unreadable or have non-json format
            raise BaseSelectorError({'message': "File %(file)s read/parse error: %(error)s",
                                     'context': {'file': json_config_path, 'error': str(e)}})

def get_htaccess_by_appdir(self, user, app_dir, doc_root, app_config=None):
        """
        Retrieve .htaccess for user and app
        :param user: Username
        :param app_dir: App dir
        :param doc_root: Document root for selected domain
        :param app_config: Optional app configuration
        :return: .htaccess full path
        """
        try:
            if app_config is None:
                app_config = self.get_app_config(user, app_dir)
            return os.path.join(doc_root, app_config['app_uri'], '.htaccess')
        except KeyError:
            return None

def set_app_status(self, user, app_dir, new_status):
        """
        Retrieves application status
        :param user: User name
        :param app_dir: Application directory
        :param new_status: New appication status
        :type new_status: str
        :return: None
        """
        user_config_data = self.get_user_config_data(user)
        try:
            app_config = get_using_realpath_keys(user, app_dir, user_config_data)
            app_config['app_status'] = new_status
        except KeyError:
            return
        # Write new config to file
        self.write_full_user_config_data(user, user_config_data)

def write_full_user_config_data(self, user, config_data):
        """
        Write data to user's config
        :param user: name of unix user
        :param config_data: data in json format
        :return: None
        """
        json_config_path = self._get_path_to_user_config(user)

if os.geteuid() == 0 or os.getegid() == 0:
            raise ClSelectExcept.SelectorException(
                'root should not write to user config')
        dumped_data = pretty_json(config_data)
        try:
            # DiD (F-18, CLOS-5532): write the per-user selector JSON at
            # 0o600 so only the owning uid (and root) can read it. CageFS
            # namespace isolation is the primary boundary — see the
            # existing invariant at get_applications_users_info that clamps
            # non-root callers to their own uid — but tightening the on-disk
            # mode closes the data_exposure class regardless of whether the
            # invariant is bypassed by a future refactor.
            secureio.write_file_via_tempfile(
                content=dumped_data,
                dest_path=json_config_path,
                perm=0o600,
                suffix='_tmp',
            )
        except (IOError, OSError, TypeError) as e:
            raise ClSelectExcept.UnableToSaveData(
                json_config_path,
                'Could not write json user config ({})'.format(e))

def is_version_in_use(self, version):
        """
        Returns True if specified NodeJS version is in use by any app of any user.
        It will stop search on the first match.
        :param version: NodeJS interpreter major version
        :return True | False
        """

user_info = self.get_users_dict()

for user_name, user_pw_entry in iteritems(user_info):
            try:
                # Get user's [python|ruby|node]-selector.json file as dictionary
                user_apps_data = self.read_user_selector_config_json(user_pw_entry.pw_dir, user_pw_entry.pw_uid,
                                                                     user_pw_entry.pw_gid)
                if user_apps_data is not None:
                    for app in user_apps_data.values():              #pylint: disable=E1101
                        if app.get('%s_version' % self.INTERPRETER) == version:
                            return True
            except AbsentFileError:
                # just skip this error, as it means than config file
                # is not created yet or it was removed by user
                pass
            except BaseSelectorError as e:
                self.write_string_to_log(e.message % e.context)  # pylint: disable=exception-message-attribute
        return False

def get_applications_users_info(self, user=None):
        """
        Retrieves info about all installed NodeJS interpreters and user(s) applictions
        :param user: User name for read applictions. If None and current euid == 0 - all users will be processed.
            If current euid != 0 (called under some user), this argument will be ignored
             and only user with uid == euid will be processed
        :return: Dictionary with user(s) applications info
        :raises ClSelectExcept.NoSuchUser or BaseSelectorError
        """
        # Enforce the documented invariant (F-36): a non-root caller may only
        # read its OWN selector data. The clamp is unconditional — both None
        # (which would expand to every system user via get_users_dict) AND an
        # explicit user argument get overridden with the caller's own UID
        # whenever euid != 0. Without this, a non-root caller passing
        # user='victim' would reach read_user_selector_config_json() against
        # victim's homedir. On-disk configs are now written at 0o600
        # (F-18 DiD, see write_full_user_config_data above), so a DAC
        # boundary also protects cross-user reads today — but this invariant
        # remains the primary defence: read_user_selector_config_json's
        # euid==0 branch drops privileges via secureio.read_file_secure and
        # would otherwise leak victim's config to a root-privileged caller
        # bypassing this clamp. Only root callers may supply a foreign user.
        if os.geteuid() != 0:
            user = _stdpwd.getpwuid(os.geteuid()).pw_name
        try:
            user_info = self.get_users_dict(user)
        except secureio.clpwd.NoSuchUserException:
            raise ClSelectExcept.NoSuchUser(user)
        users_apps_info = self._get_interpreter_info()
        available_versions = users_apps_info['available_versions']

# Process all needed users
        for user_name, user_pw_entry in iteritems(user_info):
            try:
                # Get user's [python|ruby|node]-selector.json file as dictionary
                user_apps_data = self.read_user_selector_config_json(user_pw_entry.pw_dir, user_pw_entry.pw_uid,
                                                                     user_pw_entry.pw_gid)
                # User applications data was read successfully - process it
                self._add_all_user_apps(user_pw_entry, available_versions, user_apps_data)
            except AbsentFileError:
                # just skip this error, as it means than config file
                # is not created yet or it was removed by user
                pass
            except BaseSelectorError as e:
                # Error retrieving data from user's [python|ruby|node]-selector.json
                if os.geteuid() == 0:
                    # we are root - write message to log
                    # TODO: add errors logging of broken configs
                    self.write_string_to_log(e.message % e.context)  # pylint: disable=exception-message-attribute
                    users_apps_info['warning'] = 'Some user\'s %s can\'t be read. ' \
                                                 'Some user(s) data absent in output. Please see file %s for details' % \
                                                 (self._USER_CONFIG, self._LOG_FILE_NAME)
                else:
                    # we are user - show exception
                    raise e
            except Exception as e:
                # The selector JSON is user-writable, so any unexpected
                # error processing one user's data (KeyError on a missing
                # field, TypeError on an unexpected type, etc.) must not
                # abort aggregation for everyone else when this runs as
                # root for an admin caller. Surface the failure via the
                # same warning channel as BaseSelectorError; rethrow when
                # the caller is the user themselves so the existing
                # user-side error contract is preserved.
                if os.geteuid() == 0:
                    self.write_string_to_log(
                        'Failed to process %s for user %s: %s' % (
                            self._USER_CONFIG, user_name, e))
                    users_apps_info['warning'] = 'Some user\'s %s can\'t be read. ' \
                                                 'Some user(s) data absent in output. Please see file %s for details' % \
                                                 (self._USER_CONFIG, self._LOG_FILE_NAME)
                else:
                    raise
        return users_apps_info

def get_app_folders(self, username, app_root, chk_env=True, chk_app_root=True):
        """
        Calculate, check exists and return application folders
        This method does not check that application exists in config.
        :raises: NoSuchUserException, MissingVirtualenvError, MissingAppRootError
        :return: tuple(app_root, app_venv) with absolute paths
        """
        user_home = self._pwd.get_pw_by_name(username).pw_dir
        app_venv = os.path.join(user_home, self.VENV_DIR, app_root)
        if chk_env and not os.path.exists(app_venv):
            raise MissingVirtualenvError(app_venv)

app_root = os.path.join(user_home, app_root)
        if chk_app_root and not os.path.exists(app_root):
            raise MissingAppRootError(app_root)

return app_root, app_venv

def _get_interpreter_info(self):
        """Get initial information about interpreter"""
        users_apps_info = self._manager.get_summary()
        return users_apps_info

def acquire_interpreter_lock(self, it_version):
        """
        Just a public proxy to internal method that blocks
        any actions with interpreter
        """
        return self._manager.pkg.acquire_interpreter_lock(it_version)

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