adding peru override watch

peru/main.py

@@ -187,6 +187,7 @@ def do_copy(params):
     peru override [list]
     peru override add <module> <path>
     peru override delete <module>
+    peru override watch
     peru override --help
 
 Adding an override tells peru to use the contents of a given directory
@@ -205,6 +206,7 @@ def do_copy(params):
 Options:
     -h --help  (>'-')> <('-'<) ^('-')^
 ''')
+
 def do_override(params):
     if params.args['add']:
         name = params.args['<module>']
@@ -213,6 +215,8 @@ def do_override(params):
     elif params.args['delete']:
         key = params.args['<module>']
         del params.runtime.overrides[key]
+    elif params.args['watch']:
+        params.runtime.watch_overrides()
     else:
         for module in sorted(params.runtime.overrides):
             print('{}: {}'.format(module, params.runtime.get_override(module)))

peru/runtime.py

@@ -3,6 +3,9 @@
 import os
 from pathlib import Path
 import tempfile
+import logging
+import sys
+import time
 
 from . import cache
 from . import compat
@@ -11,6 +14,8 @@
 from .keyval import KeyVal
 from . import parser
 from . import plugin
+from watchdog.observers import Observer
+from watchdog.events import LoggingEventHandler
 
 
 @asyncio.coroutine
@@ -139,6 +144,67 @@ def print_overrides(self):
             self.display.print('  {}: {}'.format(
                 name, self.get_override(name)))
 
+    def watch_overrides(self):
+        class WatchHandler(LoggingEventHandler):
+            logging.basicConfig(level=logging.INFO,
+                            format='%(asctime)s - %(message)s',
+                            datefmt='%Y-%m-%d %H:%M:%S')
+
+            def on_moved(self, event):
+                super(LoggingEventHandler, self).on_moved(event)
+                what = 'directory' if event.is_directory else 'file'
+                logging.info('moved %s: from %s to %s', what, event.src_path,
+                             event.dest_path)
+                logging.info('running peru sync --force')
+                os.system('peru sync --force')
+                logging.info('overrides synced')
+
+            def on_created(self, event):
+                super(LoggingEventHandler, self).on_created(event)
+                what = 'directory' if event.is_directory else 'file'
+                logging.info('Created %s: %s', what, event.src_path)
+                logging.info('running peru sync --force')
+                os.system('peru sync --force')
+                logging.info('overrides synced')
+
+            def on_deleted(self, event):
+                super(LoggingEventHandler, self).on_deleted(event)
+                what = 'directory' if event.is_directory else 'file'
+                logging.info('Deleted %s: %s', what, event.src_path)
+                logging.info('running peru sync --force')
+                os.system('peru sync --force')
+                logging.info('overrides synced')
+
+            def on_modified(self, event):
+                super(LoggingEventHandler, self).on_modified(event)
+                what = 'directory' if event.is_directory else 'file'
+                logging.info('Modified %s: %s', what, event.src_path)
+                logging.info('running peru sync --force')
+                os.system('peru sync --force')
+                logging.info('overrides synced')
+
+        event_handler = WatchHandler()
+        observer = Observer()
+
+        if not self.overrides:
+            print('WARNING: no overrides found')
+            return
+
+        print('watching overrides:')
+        for module in self.overrides:
+            observer.schedule(event_handler, self.get_override(module), recursive=True)
+            print('  ' + module)
+
+        observer.start()
+
+        try:
+            while True:
+                time.sleep(1)
+        except KeyboardInterrupt:
+            observer.stop()
+
+        observer.join()
+
     def warn_unused_overrides(self):
         if self.quiet or self.no_overrides:
             return

setup.py

@@ -28,7 +28,7 @@ def get_all_resources_filepaths():
 
 
 def get_install_requires():
-    dependencies = ['docopt', 'PyYAML']
+    dependencies = ['docopt', 'PyYAML', 'watchdog']
     # Python 3.3 needs extra libs that aren't installed by default.
     if sys.version_info < (3, 3):
         raise RuntimeError('The minimum supported Python version is 3.3.')