Allow bypassing the logging setup via the Python API

Signed-off-by: Bernat Gabor <bgabor8@bloomberg.net>

docs/changelog/1896.bugfix.rst

@@ -0,0 +1,2 @@
+Provide ``setup_logging`` flag to python API so that users can bypass logging handling if their application already
+performs this - by :user:`gaborbernat`.

src/virtualenv/__init__.py

@@ -1,9 +1,10 @@
 from __future__ import absolute_import, unicode_literals
 
-from .run import cli_run
+from .run import cli_run, session_via_cli
 from .version import __version__
 
 __all__ = (
  "__version__",
  "cli_run",
+ "session_via_cli",
 )

src/virtualenv/run/__init__.py

@@ -14,30 +14,39 @@
 from .plugin.seeders import SeederSelector
 
 
-def cli_run(args, options=None):
- """Create a virtual environment given some command line interface arguments
+def cli_run(args, options=None, setup_logging=True):
+ """
+ Create a virtual environment given some command line interface arguments.
 
  :param args: the command line arguments
  :param options: passing in a ``VirtualEnvOptions`` object allows return of the parsed options
+ :param setup_logging: ``True`` if setup logging handlers, ``False`` to use handlers already registered
  :return: the session object of the creation (its structure for now is experimental and might change on short notice)
  """
- session = session_via_cli(args, options)
- with session:
- session.run()
- return session
+ of_session = session_via_cli(args, options, setup_logging)
+ with of_session:
+ of_session.run()
+ return of_session
+
 
+def session_via_cli(args, options=None, setup_logging=True):
+ """
+ Create a virtualenv session (same as cli_run, but this does not perform the creation). Use this if you just want to
+ query what the virtual environment would look like, but not actually create it.
 
-# noinspection PyProtectedMember
-def session_via_cli(args, options=None):
- parser, elements = build_parser(args, options)
+ :param args: the command line arguments
+ :param options: passing in a ``VirtualEnvOptions`` object allows return of the parsed options
+ :param setup_logging: ``True`` if setup logging handlers, ``False`` to use handlers already registered
+ :return: the session object of the creation (its structure for now is experimental and might change on short notice)
+ """
+ parser, elements = build_parser(args, options, setup_logging)
  options = parser.parse_args(args)
  creator, seeder, activators = tuple(e.create(options) for e in elements) # create types
- session = Session(options.verbosity, options.app_data, parser._interpreter, creator, seeder, activators)
- return session
+ of_session = Session(options.verbosity, options.app_data, parser._interpreter, creator, seeder, activators) # noqa
+ return of_session
 
 
-# noinspection PyProtectedMember
-def build_parser(args=None, options=None):
+def build_parser(args=None, options=None, setup_logging=True):
  parser = VirtualEnvConfigParser(options)
  add_version_flag(parser)
  parser.add_argument(
@@ -47,7 +56,7 @@ def build_parser(args=None, options=None):
  default=False,
  help="on failure also display the stacktrace internals of virtualenv",
  )
- _do_report_setup(parser, args)
+ _do_report_setup(parser, args, setup_logging)
  options = load_app_data(args, parser, options)
  handle_extra_commands(options)
 
@@ -121,7 +130,7 @@ def add_version_flag(parser):
  )
 
 
-def _do_report_setup(parser, args):
+def _do_report_setup(parser, args, setup_logging):
  level_map = ", ".join("{}={}".format(logging.getLevelName(l), c) for c, l in sorted(list(LEVELS.items())))
  msg = "verbosity = verbose - quiet, default {}, mapping => {}"
  verbosity_group = parser.add_argument_group(
@@ -131,4 +140,11 @@ def _do_report_setup(parser, args):
  verbosity.add_argument("-v", "--verbose", action="count", dest="verbose", help="increase verbosity", default=2)
  verbosity.add_argument("-q", "--quiet", action="count", dest="quiet", help="decrease verbosity", default=0)
  option, _ = parser.parse_known_args(args)
- setup_report(option.verbosity)
+ if setup_logging:
+ setup_report(option.verbosity)
+
+
+__all__ = (
+ "cli_run",
+ "session_via_cli",
+)

tests/conftest.py

@@ -196,8 +196,8 @@ def coverage_env(monkeypatch, link, request):
  # we inject right after creation, we cannot collect coverage on site.py - used for helper scripts, such as debug
  from virtualenv import run
 
- def via_cli(args, options):
- session = prev_run(args, options)
+ def _session_via_cli(args, options, setup_logging):
+ session = prev_run(args, options, setup_logging)
  old_run = session.creator.run
 
  def create_run():
@@ -211,7 +211,7 @@ def create_run():
 
  obj = {"cov": None}
  prev_run = run.session_via_cli
- monkeypatch.setattr(run, "session_via_cli", via_cli)
+ monkeypatch.setattr(run, "session_via_cli", _session_via_cli)
 
  def finish():
  cov = obj["cov"]

tests/unit/config/test___main__.py

@@ -24,8 +24,8 @@ def _func(exception):
 
  prev_session = session_via_cli
 
- def _session_via_cli(args, options=None):
- prev_session(args, options)
+ def _session_via_cli(args, options=None, setup_logging=True):
+ prev_session(args, options, setup_logging)
  raise exception
 
  mocker.patch("virtualenv.run.session_via_cli", side_effect=_session_via_cli)

tests/unit/create/test_creator.py

@@ -250,8 +250,8 @@ def test_venv_fails_not_inline(tmp_path, capsys, mocker):
  if os.geteuid() == 0:
  pytest.skip("no way to check permission restriction when running under root")
 
- def _session_via_cli(args, options=None):
- session = session_via_cli(args, options)
+ def _session_via_cli(args, options=None, setup_logging=True):
+ session = session_via_cli(args, options, setup_logging)
  assert session.creator.can_be_inline is False
  return session
 

tests/unit/test_run.py

@@ -1,10 +1,12 @@
 from __future__ import absolute_import, unicode_literals
 
+import logging
+
 import pytest
 import six
 
 from virtualenv import __version__
-from virtualenv.run import cli_run
+from virtualenv.run import cli_run, session_via_cli
 
 
 def test_help(capsys):
@@ -31,3 +33,14 @@ def test_version(capsys):
  import virtualenv
 
  assert virtualenv.__file__ in content
+
+
+@pytest.mark.parametrize("on", [True, False])
+def test_logging_setup(caplog, on):
+ caplog.set_level(logging.DEBUG)
+ session_via_cli(["env"], setup_logging=on)
+ # DEBUG only level output is generated during this phase, default output is WARN, so if on no records should be
+ if on:
+ assert not caplog.records
+ else:
+ assert caplog.records