CC-2977: Never delete files from the database

- Files are marked deleted(file_exists to false) on deletion.
- Dirs are marked removed(removed flag to true) on removal of watched
folder in a usual way. If dir is unmounted, without being removed from
watched list first, it will be marked as not exists(exist flag to false)
- Manage Media Folders will show if dirs exist or not( mounted or not)
- Playlist builder will show if files exists or not

python_apps/media-monitor/airtimefilemonitor/airtimemediamonitorbootstrap.py

@@ -1,11 +1,12 @@
 import os
 import time
+import pyinotify
 
 from subprocess import Popen, PIPE
 from api_clients import api_client
 
 class AirtimeMediaMonitorBootstrap():
-
+    
     """AirtimeMediaMonitorBootstrap constructor
 
     Keyword Arguments:
@@ -13,11 +14,16 @@ class AirtimeMediaMonitorBootstrap():
     pe          -- reference to an instance of ProcessEvent
     api_clients -- reference of api_clients to communicate with airtime-server
     """
-    def __init__(self, logger, pe, api_client, mmc):
+    def __init__(self, logger, pe, api_client, mmc, wm):
         self.logger = logger
         self.pe = pe
         self.api_client = api_client
         self.mmc = mmc
+        self.wm = wm
+        # add /etc on watch list so we can detect mount
+        self.mount_file = "/etc"
+        self.logger.info("Adding %s on watch list...", self.mount_file)
+        self.wm.add_watch(self.mount_file, pyinotify.ALL_EVENTS, rec=False, auto_add=False)
 
     """On bootup we want to scan all directories and look for files that
     weren't there or files that changed before media-monitor process
@@ -79,6 +85,10 @@ class AirtimeMediaMonitorBootstrap():
             if len(file_path.strip(" \n")) > 0:
                 all_files_set.add(file_path[len(dir):])
 
+        # if dir doesn't exists, update db
+        if not os.path.exists(dir):
+            self.pe.handle_watched_dir_missing(dir)
+
         if os.path.exists(self.mmc.timestamp_file):
             """find files that have been modified since the last time media-monitor process started."""
             time_diff_sec = time.time() - os.path.getmtime(self.mmc.timestamp_file)