Merge pull request #79 from cleverdevil/next

Updated paste serve with reload

pecan/commands/serve.py

@@ -2,6 +2,10 @@
 Serve command for Pecan.
 """
 import os
+import sys
+import time
+import subprocess
+
 from pecan.commands import BaseCommand
 
 
@@ -13,26 +17,93 @@ class ServeCommand(BaseCommand):
     configuration file for the server and application.
     """
 
+    arguments = ({
+        'command': 'config_file',
+        'help': 'a Pecan configuration file'
+    }, {
+        'command': '--reload',
+        'help': 'Watch for changes and automatically reload.',
+        'default': False,
+        'action': 'store_true'
+    })
+
     def run(self, args):
         super(ServeCommand, self).run(args)
         app = self.load_app()
         self.serve(app, app.config)
 
-    def serve(self, app, conf):
-        """
-        A very simple approach for a WSGI server.
-        """
+    def create_subprocess(self):
+        self.server_process = subprocess.Popen(
+            [arg for arg in sys.argv if arg != '--reload'],
+            stdout=sys.stdout, stderr=sys.stderr
+        )
+
+    def watch_and_spawn(self):
+        from watchdog.observers import Observer
+        from watchdog.events import FileSystemEventHandler
+
+        print 'Monitoring for changes...'
+        self.create_subprocess()
+
+        parent = self
+
+        class AggressiveEventHandler(FileSystemEventHandler):
+            def should_reload(self, path):
+                extension = os.path.splitext(path)[1]
+                if extension in (
+                    '.py', '.pyc', '.html', '.mak',
+                    '.mako', '.xml'
+                ):
+                    return True
+                return False
+
+            def on_modified(self, event):
+                if self.should_reload(getattr(event, 'src_path', '')):
+                    parent.server_process.kill()
+                    parent.create_subprocess()
+
+        event_handler = AggressiveEventHandler()
+        observer = Observer()
+        observer.schedule(event_handler, path=os.getcwd(), recursive=True)
+        observer.start()
+
+        try:
+            while True:
+                time.sleep(1)
+        except KeyboardInterrupt:
+            pass
+
+    def _serve(self, app, conf):
         from wsgiref.simple_server import make_server
+
         host, port = conf.server.host, int(conf.server.port)
         srv = make_server(host, port, app)
+
         print 'Starting server in PID %s' % os.getpid()
+
         if host == '0.0.0.0':
             print 'serving on 0.0.0.0:%s, view at http://127.0.0.1:%s' % \
                 (port, port)
         else:
             print "serving on http://%s:%s" % (host, port)
+
         try:
             srv.serve_forever()
         except KeyboardInterrupt:
             # allow CTRL+C to shutdown
             pass
+
+    def serve(self, app, conf):
+        """
+        A very simple approach for a WSGI server.
+        """
+
+        if self.args.reload:
+            try:
+                self.watch_and_spawn()
+            except ImportError:
+                print('The `--reload` option requires `watchdog` to be '
+                      'installed.')
+                print('   $ pip install watchdog')
+        else:
+            self._serve(app, conf)