| from __future__ import absolute_import |
| |
| import io |
| import logging |
| import os |
| import re |
| import site |
| import sys |
| |
| from pip._internal.utils.typing import MYPY_CHECK_RUNNING |
| |
| if MYPY_CHECK_RUNNING: |
| from typing import List, Optional |
| |
| logger = logging.getLogger(__name__) |
| _INCLUDE_SYSTEM_SITE_PACKAGES_REGEX = re.compile( |
| r"include-system-site-packages\s*=\s*(?P<value>true|false)" |
| ) |
| |
| |
| def _running_under_venv(): |
| # type: () -> bool |
| """Checks if sys.base_prefix and sys.prefix match. |
| |
| This handles PEP 405 compliant virtual environments. |
| """ |
| return sys.prefix != getattr(sys, "base_prefix", sys.prefix) |
| |
| |
| def _running_under_regular_virtualenv(): |
| # type: () -> bool |
| """Checks if sys.real_prefix is set. |
| |
| This handles virtual environments created with pypa's virtualenv. |
| """ |
| # pypa/virtualenv case |
| return hasattr(sys, 'real_prefix') |
| |
| |
| def running_under_virtualenv(): |
| # type: () -> bool |
| """Return True if we're running inside a virtualenv, False otherwise. |
| """ |
| return _running_under_venv() or _running_under_regular_virtualenv() |
| |
| |
| def _get_pyvenv_cfg_lines(): |
| # type: () -> Optional[List[str]] |
| """Reads {sys.prefix}/pyvenv.cfg and returns its contents as list of lines |
| |
| Returns None, if it could not read/access the file. |
| """ |
| pyvenv_cfg_file = os.path.join(sys.prefix, 'pyvenv.cfg') |
| try: |
| # Although PEP 405 does not specify, the built-in venv module always |
| # writes with UTF-8. (pypa/pip#8717) |
| with io.open(pyvenv_cfg_file, encoding='utf-8') as f: |
| return f.read().splitlines() # avoids trailing newlines |
| except IOError: |
| return None |
| |
| |
| def _no_global_under_venv(): |
| # type: () -> bool |
| """Check `{sys.prefix}/pyvenv.cfg` for system site-packages inclusion |
| |
| PEP 405 specifies that when system site-packages are not supposed to be |
| visible from a virtual environment, `pyvenv.cfg` must contain the following |
| line: |
| |
| include-system-site-packages = false |
| |
| Additionally, log a warning if accessing the file fails. |
| """ |
| cfg_lines = _get_pyvenv_cfg_lines() |
| if cfg_lines is None: |
| # We're not in a "sane" venv, so assume there is no system |
| # site-packages access (since that's PEP 405's default state). |
| logger.warning( |
| "Could not access 'pyvenv.cfg' despite a virtual environment " |
| "being active. Assuming global site-packages is not accessible " |
| "in this environment." |
| ) |
| return True |
| |
| for line in cfg_lines: |
| match = _INCLUDE_SYSTEM_SITE_PACKAGES_REGEX.match(line) |
| if match is not None and match.group('value') == 'false': |
| return True |
| return False |
| |
| |
| def _no_global_under_regular_virtualenv(): |
| # type: () -> bool |
| """Check if "no-global-site-packages.txt" exists beside site.py |
| |
| This mirrors logic in pypa/virtualenv for determining whether system |
| site-packages are visible in the virtual environment. |
| """ |
| site_mod_dir = os.path.dirname(os.path.abspath(site.__file__)) |
| no_global_site_packages_file = os.path.join( |
| site_mod_dir, 'no-global-site-packages.txt', |
| ) |
| return os.path.exists(no_global_site_packages_file) |
| |
| |
| def virtualenv_no_global(): |
| # type: () -> bool |
| """Returns a boolean, whether running in venv with no system site-packages. |
| """ |
| # PEP 405 compliance needs to be checked first since virtualenv >=20 would |
| # return True for both checks, but is only able to use the PEP 405 config. |
| if _running_under_venv(): |
| return _no_global_under_venv() |
| |
| if _running_under_regular_virtualenv(): |
| return _no_global_under_regular_virtualenv() |
| |
| return False |