Fix validate_reload by returning the validated value (#1378)

* Fix validate_reload by returning the validated value

When '--reload=RELOADER_TYPE' was implemented, `validate_reload()` was
added but in one of the last refactorings, it lost the return statement
at the end of the function. As a result, the '--reload' config value was
totally broken.

This resolves the issue by adding the missing return.

* Fix tests by changing --reload to always require an argument

- '--reload' always requires an argument now
- Added 'auto' as the default value for '--reload'

docs/source/settings.rst

@@ -256,7 +256,7 @@ reload
 ~~~~~~
 
 * ``--reload RELOADER_TYPE``
-* ``None``
+* ``off``
 
 Restart workers when code changes.
 
@@ -270,8 +270,8 @@ application code or the reload will not work as designed.
 When using this option, you can optionally specify whether you would
 like to use file system polling or the kernel's inotify API to watch
 for changes. Generally, inotify should be preferred if available
-because it consumes less system resources. If no preference is given,
+because it consumes less system resources. The default behavior (auto)
-inotify will attempted with a fallback to FS polling.
+is to attempt inotify with a fallback to FS polling.
 
 Note: In order to use the inotify reloader, you must have the 'inotify'
 package installed.

gunicorn/config.py

@@ -492,15 +492,17 @@ def validate_hostport(val):
 
 def validate_reloader(val):
     if val is None:
-        val = 'default'
+        val = 'auto'
 
-    choices = ['poll', 'inotify', 'default']
+    choices = ['auto', 'poll', 'inotify', 'off']
 
     if val not in choices:
         raise ConfigError(
             'Invalid reloader type. Must be one of: %s' % choices
         )
 
+    return val
+
 
 def get_default_config_file():
     config_path = os.path.join(os.path.abspath(os.getcwd()),
@@ -820,9 +822,7 @@ class Reload(Setting):
     section = 'Debugging'
     cli = ['--reload']
     validator = validate_reloader
-    nargs = '?'
+    default = 'off'
-    const = 'default'
-    default = None
     meta = 'RELOADER_TYPE'
 
     desc = '''\
@@ -838,8 +838,8 @@ class Reload(Setting):
         When using this option, you can optionally specify whether you would
         like to use file system polling or the kernel's inotify API to watch
         for changes. Generally, inotify should be preferred if available
-        because it consumes less system resources. If no preference is given,
+        because it consumes less system resources. The default behavior (auto)
-        inotify will attempted with a fallback to FS polling.
+        is to attempt inotify with a fallback to FS polling.
 
         Note: In order to use the inotify reloader, you must have the 'inotify'
         package installed.

gunicorn/workers/base.py

@@ -115,7 +115,7 @@ class Worker(object):
         self.load_wsgi()
 
         # start the reloader
-        if self.cfg.reload:
+        if self.cfg.reload and self.cfg.reload != 'off':
             def changed(fname):
                 self.log.info("Worker reloading: %s modified", fname)
                 self.alive = False