Fixes for issue #1114

1. Moved RESTART_EXIT_CODE to constants so it can safely be used by
__main__.py.
2. Allowed __main__/main to return the desired exit code.
3. Forwarded the child processes exit code to the parent process to be
duplicated.
4. Added —debug flag to pass command to force Home Assistant to run in
only one process. A warning is printed to STDERR to indicate HASS is in
debug mode. Another is printed if HASS requests a restart in debug
mode. A restart request in debug mode will quit.
5. Added an argument to __main__/main/setup_and_run_hass to indicate
that it is running in the top process. This tells it to return the exit
code rather than exiting.

homeassistant/__main__.py

@@ -10,7 +10,8 @@ import argparse
 
 from homeassistant import bootstrap
 import homeassistant.config as config_util
-from homeassistant.const import __version__, EVENT_HOMEASSISTANT_START
+from homeassistant.const import (__version__, EVENT_HOMEASSISTANT_START,
+                                 RESTART_EXIT_CODE)
 
 
 def validate_python():
@@ -76,6 +77,11 @@ def get_arguments():
         '--demo-mode',
         action='store_true',
         help='Start Home Assistant in demo mode')
+    parser.add_argument(
+        '--debug',
+        action='store_true',
+        help='Start Home Assistant in debug mode. Runs in single process to '
+        'enable use of interactive debuggers.')
     parser.add_argument(
         '--open-ui',
         action='store_true',
@@ -207,8 +213,11 @@ def uninstall_osx():
     print("Home Assistant has been uninstalled.")
 
 
-def setup_and_run_hass(config_dir, args):
-    """ Setup HASS and run. Block until stopped. """
+def setup_and_run_hass(config_dir, args, top_process=False):
+    """
+    Setup HASS and run. Block until stopped. Will assume it is running in a
+    subprocess unless top_process is set to true.
+    """
     if args.demo_mode:
         config = {
             'frontend': {},
@@ -235,7 +244,11 @@ def setup_and_run_hass(config_dir, args):
         hass.bus.listen_once(EVENT_HOMEASSISTANT_START, open_browser)
 
     hass.start()
-    sys.exit(int(hass.block_till_stopped()))
+    exit_code = int(hass.block_till_stopped())
+
+    if not top_process:
+        sys.exit(exit_code)
+    return exit_code
 
 
 def run_hass_process(hass_proc):
@@ -262,7 +275,10 @@ def run_hass_process(hass_proc):
             hass_proc.join()
         except KeyboardInterrupt:
             return False
-    return not requested_stop.isSet() and hass_proc.exitcode == 100
+
+    return (not requested_stop.isSet() and
+            hass_proc.exitcode == RESTART_EXIT_CODE,
+            hass_proc.exitcode)
 
 
 def main():
@@ -277,14 +293,14 @@ def main():
     # os x launchd functions
     if args.install_osx:
         install_osx()
-        return
+        return 0
     if args.uninstall_osx:
         uninstall_osx()
-        return
+        return 0
     if args.restart_osx:
         uninstall_osx()
         install_osx()
-        return
+        return 0
 
     # daemon functions
     if args.pid_file:
@@ -294,12 +310,23 @@ def main():
     if args.pid_file:
         write_pid(args.pid_file)
 
+    # Run hass in debug mode if requested
+    if args.debug:
+        sys.stderr.write('Running in debug mode. '
+                         'Home Assistant will not be able to restart.\n')
+        exit_code = setup_and_run_hass(config_dir, args, top_process=True)
+        if exit_code == RESTART_EXIT_CODE:
+            sys.stderr.write('Home Assistant requested a '
+                             'restart in debug mode.\n')
+        return exit_code
+
     # Run hass as child process. Restart if necessary.
     keep_running = True
     while keep_running:
         hass_proc = Process(target=setup_and_run_hass, args=(config_dir, args))
-        keep_running = run_hass_process(hass_proc)
+        keep_running, exit_code = run_hass_process(hass_proc)
+    return exit_code
 
 
 if __name__ == "__main__":
-    main()
+    sys.exit(main())

homeassistant/const.py

@@ -197,3 +197,6 @@ HTTP_HEADER_EXPIRES = "Expires"
 CONTENT_TYPE_JSON = "application/json"
 CONTENT_TYPE_MULTIPART = 'multipart/x-mixed-replace; boundary={}'
 CONTENT_TYPE_TEXT_PLAIN = 'text/plain'
+
+# The exit code to send to request a restart
+RESTART_EXIT_CODE = 100

homeassistant/core.py

@@ -20,7 +20,8 @@ from homeassistant.const import (
     EVENT_TIME_CHANGED, EVENT_STATE_CHANGED,
     EVENT_CALL_SERVICE, ATTR_NOW, ATTR_DOMAIN, ATTR_SERVICE, MATCH_ALL,
     EVENT_SERVICE_EXECUTED, ATTR_SERVICE_CALL_ID, EVENT_SERVICE_REGISTERED,
-    TEMP_CELCIUS, TEMP_FAHRENHEIT, ATTR_FRIENDLY_NAME, ATTR_SERVICE_DATA)
+    TEMP_CELCIUS, TEMP_FAHRENHEIT, ATTR_FRIENDLY_NAME, ATTR_SERVICE_DATA,
+    RESTART_EXIT_CODE)
 from homeassistant.exceptions import (
     HomeAssistantError, InvalidEntityFormatError)
 import homeassistant.util as util
@@ -48,9 +49,6 @@ _LOGGER = logging.getLogger(__name__)
 # Temporary to support deprecated methods
 _MockHA = namedtuple("MockHomeAssistant", ['bus'])
 
-# The exit code to send to request a restart
-RESTART_EXIT_CODE = 100
-
 
 class HomeAssistant(object):
     """Root object of the Home Assistant home automation."""