new upload script with /mnt/sd card as backup

opencv-motion-detect/upload_video.py

@@ -14,7 +14,7 @@ kSchedIntervalSec = 3 * 60
 kSliceIntervalSec = 30
 
 ## storage water marks
-kSDCardFreeMBWMLow = 300
+kSDCardFreeMBWMLow = 500
 kSDCardFreeMBWMHigh = 1024 # not used, instead we use timeshift below
 ## clean from the oldest files, total 1 hour
 kSDCardCleanupTimeShiftMinutes = 60
@@ -93,18 +93,19 @@ def cleanup(target):
     mbfree = st.f_bavail * st.f_bsize/1024/1024
     logger.info("mb free: {}\n{}".format(mbfree, st))
     if mbfree > kSDCardFreeMBWMLow:
+        logger.info('no need to free space')
         pass
     else:
         # find out the oldest N files in SD card
         # ALERT: must use generator to save memory, otherwise it prons to OOM by stacks of files on SD card
         number_files = int(kSDCardCleanupTimeShiftMinutes * 60/kSliceIntervalSec)
-        oldest_n_mtime = [] # ten digits
-        oldest_n_files = []
+        oldest_n_mtime = [None for _ in range(number_files)] # ten digits
+        oldest_n_files = [None for _ in range(number_files)]
         cnt = 0
         for dir_ in Path(target).iterdir():
             if not dir_.is_dir():
                 continue
-            for file in Path(dir_.absolute()):
+            for file in Path(dir_.absolute()).iterdir():
                 if not file.is_file():
                     continue
                 mts = file.stat().st_mtime
@@ -125,6 +126,7 @@ def cleanup(target):
         # clean up
         for f in oldest_n_files:
             os.remove(str(f))
+            logger.info('removed file %s', f)
 
 def lookup(src, file, backup):
     file = src+ '/' + file
@@ -192,12 +194,14 @@ def upload_file(file):
 
     return success
 
-# 1. backup & cleanup
-# 2. upload jobs
 if __name__ == "__main__":
-    #list_files_by_ext('.', 'json')
-    # make sufficient margins for long running uploader & slicer
-    #logger.info(files)
+    '''
+        1. backup & cleanup
+        2. upload jobs
+    '''
+    # single instance
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    s.bind(('localhost', 45431))
     logger.setLevel(logging.INFO)
     try:
         #