Now using watchdog to monitor a "watchdog" folder for gcode or stl files being added

Use this to define a folder on your system from which to automatically import/move added files into OctoPrint.

Also now monitoring the uploads folder so that if files are removed externally during runtime, the metadata.yaml will be cleaned up.

src/octoprint/server/__init__.py

@@ -10,6 +10,7 @@ from sockjs.tornado import SockJSRouter
 from flask import Flask, render_template, send_from_directory, make_response
 from flask.ext.login import LoginManager
 from flask.ext.principal import Principal, Permission, RoleNeed, identity_loaded, UserNeed
+from watchdog.observers import Observer
 
 import os
 import logging
@@ -33,7 +34,7 @@ user_permission = Permission(RoleNeed("user"))
 
 # only import the octoprint stuff down here, as it might depend on things defined above to be initialized already
 from octoprint.server.util import LargeResponseHandler, ReverseProxied, restricted_access, PrinterStateConnection, admin_validator, \
-	UrlForwardHandler, user_validator
+	UrlForwardHandler, user_validator, GcodeWatchdogHandler, UploadCleanupWatchdogHandler
 from octoprint.printer import Printer, getConnectionOptions
 from octoprint.settings import settings
 import octoprint.gcodefiles as gcodefiles
@@ -220,6 +221,13 @@ class Server():
 			connectionOptions = getConnectionOptions()
 			if port in connectionOptions["ports"]:
 				printer.connect(port, baudrate)
+
+		# start up watchdogs
+		observer = Observer()
+		observer.schedule(GcodeWatchdogHandler(gcodeManager, printer), settings().getBaseFolder("watchdog"))
+		observer.schedule(UploadCleanupWatchdogHandler(gcodeManager), settings().getBaseFolder("uploads"))
+		observer.start()
+
 		try:
 			IOLoop.instance().start()
 		except KeyboardInterrupt:
@@ -227,6 +235,9 @@ class Server():
 		except:
 			logger.fatal("Now that is embarrassing... Something really really went wrong here. Please report this including the stacktrace below in OctoPrint's bugtracker. Thanks!")
 			logger.exception("Stacktrace follows:")
+		finally:
+			observer.stop()
+		observer.join()
 
 	def _createSocketConnection(self, session):
 		global printer, gcodeManager, userManager, eventManager

src/octoprint/server/util.py

@@ -1,4 +1,6 @@
 # coding=utf-8
+from octoprint.filemanager.destinations import FileDestinations
+
 __author__ = "Gina Häußge <osd@foosel.net>"
 __license__ = 'GNU Affero General Public License http://www.gnu.org/licenses/agpl.html'
 
@@ -19,13 +21,15 @@ import os
 import threading
 import logging
 from functools import wraps
+from watchdog.events import PatternMatchingEventHandler
 
 from octoprint.settings import settings
 import octoprint.timelapse
 import octoprint.server
 from octoprint.users import ApiUser
 from octoprint.events import Events
-
+from octoprint import gcodefiles
+import octoprint.util as util
 
 def restricted_access(func, apiEnabled=True):
 	"""
@@ -485,3 +489,70 @@ def redirectToTornado(request, target):
 		redirectUrl += fragment
 	return redirect(redirectUrl)
 
+
+class UploadCleanupWatchdogHandler(PatternMatchingEventHandler):
+	"""
+	Takes care of automatically deleting metadata entries for files that get deleted from the uploads folder
+	"""
+
+	patterns = map(lambda x: "*.%s" % x, gcodefiles.GCODE_EXTENSIONS)
+
+	def __init__(self, gcode_manager):
+		PatternMatchingEventHandler.__init__(self)
+		self._gcode_manager = gcode_manager
+
+	def on_deleted(self, event):
+		filename = self._gcode_manager._getBasicFilename(event.src_path)
+		if not filename:
+			return
+
+		self._gcode_manager.removeFileFromMetadata(filename)
+
+
+class GcodeWatchdogHandler(PatternMatchingEventHandler):
+	"""
+	Takes care of automatically "uploading" files that get added to the watchdog folder.
+	"""
+
+	patterns = map(lambda x: "*.%s" % x, gcodefiles.SUPPORTED_EXTENSIONS)
+
+	def __init__(self, gcodeManager, printer):
+		PatternMatchingEventHandler.__init__(self)
+		self._gcodeManager = gcodeManager
+		self._printer = printer
+
+	def _upload(self, path):
+		class WatchdogFileWrapper(object):
+
+			def __init__(self, path):
+				self._path = path
+				self.filename = os.path.basename(self._path)
+
+			def save(self, target):
+				util.safeRename(self._path, target)
+
+		fileWrapper = WatchdogFileWrapper(path)
+
+		# determine current job
+		currentFilename = None
+		currentSd = None
+		currentJob = self._printer.getCurrentJob()
+		if currentJob is not None and "filename" in currentJob.keys() and "sd" in currentJob.keys():
+			currentFilename = currentJob["filename"]
+			currentSd = currentJob["sd"]
+
+		# determine future filename of file to be uploaded, abort if it can't be uploaded
+		futureFilename = self._gcodeManager.getFutureFilename(fileWrapper)
+		if futureFilename is None or (not settings().getBoolean(["cura", "enabled"]) and not gcodefiles.isGcodeFileName(futureFilename)):
+			return # Invalid file
+
+		# prohibit overwriting currently selected file while it's being printed
+		if futureFilename == currentFilename and not currentSd and self._printer.isPrinting() or self._printer.isPaused():
+			return # Trying to overwrite file that is currently being printed
+
+		self._gcodeManager.addFile(fileWrapper, FileDestinations.LOCAL)
+
+	def on_created(self, event):
+		self._upload(event.src_path)
+
+

src/octoprint/settings.py

@@ -77,7 +77,8 @@ default_settings = {
 		"timelapse": None,
 		"timelapse_tmp": None,
 		"logs": None,
-		"virtualSd": None
+		"virtualSd": None,
+		"watchdog": None
 	},
 	"temperature": {
 		"profiles":