Alow config log dir via env vars. ros2#460

launch/launch/logging/__init__.py

@@ -37,6 +37,29 @@
 ]
 
 
+def _get_logging_directory():
+    """
+    Get logging directory path.
+
+    Uses various environment variables to construct a logging directory path.
+
+    Use $ROS_LOG_DIR if ROS_LOG_DIR is set and not empty.
+    Otherwise, use $ROS_HOME/log, using ~/.ros for ROS_HOME if not set or if empty.
+
+    It also expands '~' to the current user's home directory,
+    and normalizes the path, converting the path separator if necessary.
+
+    :return: the path to the logging directory
+    """
+    log_dir = os.environ.get('ROS_LOG_DIR')
+    if not log_dir:
+        log_dir = os.environ.get('ROS_HOME')
+        if not log_dir:
+            log_dir = os.path.join('~', '.ros')
+        log_dir = os.path.join(log_dir, 'log')
+    return os.path.normpath(os.path.expanduser(log_dir))
+
+
 def _make_unique_log_dir(*, base_path):
     """
     Make a unique directory for logging.
@@ -93,7 +116,7 @@ def log_dir(self):
         """Get the current log directory, generating it if necessary."""
         if self._log_dir is None:
             self._log_dir = _make_unique_log_dir(
-                base_path=os.path.join(os.path.expanduser('~'), '.ros/log')
+                base_path=_get_logging_directory()
             )
 
         return self._log_dir

launch/test/launch/test_logging.py

@@ -16,7 +16,9 @@
 
 import logging
 import os
+import pathlib
 import re
+from unittest import mock
 
 import launch.logging
 
@@ -249,3 +251,73 @@ def emit(self, record):
     assert path in outputs
     assert len(outputs[path]) == 1
     assert outputs[path][0].endswith('baz')
+
+
+def fake_make_unique_log_dir(*, base_path):
+    # Passthrough; do not create the directory
+    return base_path
+
+
+@mock.patch('launch.logging._make_unique_log_dir', mock.MagicMock(wraps=fake_make_unique_log_dir))
+def test_get_logging_directory():
+    launch.logging.launch_config.reset()
+    os.environ.pop('ROS_LOG_DIR', None)
+    os.environ.pop('ROS_HOME', None)
+    home = pathlib.Path.home()
+    assert str(home)
+
+    # Default case without ROS_LOG_DIR or ROS_HOME being set (but with HOME)
+    default_dir = str(home / '.ros/log')
+    # This ensures that the launch config will check the environment again
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == default_dir
+
+    # Use $ROS_LOG_DIR if it is set
+    my_log_dir_raw = '/my/ros_log_dir'
+    my_log_dir = str(pathlib.Path(my_log_dir_raw))
+    os.environ['ROS_LOG_DIR'] = my_log_dir
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == my_log_dir
+    # Make sure it converts path separators when necessary
+    os.environ['ROS_LOG_DIR'] = my_log_dir_raw
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == my_log_dir
+    # Setting ROS_HOME won't change anything since ROS_LOG_DIR is used first
+    os.environ['ROS_HOME'] = '/this/wont/be/used'
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == my_log_dir
+    os.environ.pop('ROS_HOME', None)
+    # Empty is considered unset
+    os.environ['ROS_LOG_DIR'] = ''
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == default_dir
+    # Make sure '~' is expanded to the home directory
+    os.environ['ROS_LOG_DIR'] = '~/logdir'
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == str(home / 'logdir')
+
+    os.environ.pop('ROS_LOG_DIR', None)
+
+    # Without ROS_LOG_DIR, use $ROS_HOME/log
+    fake_ros_home = home / '.fakeroshome'
+    fake_ros_home_log_dir = str(fake_ros_home / 'log')
+    os.environ['ROS_HOME'] = str(fake_ros_home)
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == fake_ros_home_log_dir
+    # Make sure it converts path separators when necessary
+    my_ros_home_raw = '/my/ros/home'
+    my_ros_home_log_dir = str(pathlib.Path(my_ros_home_raw) / 'log')
+    os.environ['ROS_HOME'] = my_ros_home_raw
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == my_ros_home_log_dir
+    # Empty is considered unset
+    os.environ['ROS_HOME'] = ''
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == default_dir
+    # Make sure '~' is expanded to the home directory
+    os.environ['ROS_HOME'] = '~/.fakeroshome'
+    launch.logging.launch_config.log_dir = None
+    assert launch.logging.launch_config.log_dir == fake_ros_home_log_dir
+
+    os.environ.pop('ROS_HOME', None)
+    launch.logging.launch_config.reset()