refined file following

[logalert.git] / src / logalert.py

diff --git a/src/logalert.py b/src/logalert.py
index d240f44a38fb7e61ee648f8ebee248700d5c7b65..df9de076eb4e701577f7af5ebc83711ce6c8be2c 100755 (executable)
--- a/src/logalert.py
+++ b/src/logalert.py
@@ -7,20 +7,22 @@ import shlex
 import subprocess
 import time
 
-from line import Line
-
 MAX_LINES = 10
+ALERT_INTERVAL = 86400
 
-def follow(filename):
+def follow(path):
     while True:
         try:
-            with open(filename, "r") as f:
+            fd = os.open(path, os.O_RDONLY)
+            current_ino = os.fstat(fd).st_ino
+            with os.fdopen(fd, "r") as f:
                 logging.info("Re-attached to log file.")
                 for line in f: pass
                 while True:
                     line = f.readline()
                     if not line:
-                        if not os.path.exists(filename):
+                        if os.stat(path).st_ino != current_ino or \
+                           os.stat(path).st_size < f.tell():
                             break
                         else:
                             time.sleep(1.0)
@@ -70,45 +72,45 @@ args = parser.parse_args()
 
 kept_times = []
 lines = []
-last_time = None
+last_slot_time = None
 error_state = False
+last_alert_time = 0
 
 for line in follow(args.logfile):
-    now = int(time.time()) // args.interval_size
+    time_now = time.time()
+    slot_now = int(time_now) // args.interval_size
 
     if line != None:
-        if not last_time or now > last_time:
-            kept_times.append(now)
-            last_time = now
+        if not last_slot_time or slot_now > last_slot_time:
+            kept_times.append(slot_now)
+            last_slot_time = slot_now
         lines.append(line)
         if len(lines) > MAX_LINES:
             lines.pop(0)
 
     while len(kept_times) > 0 and \
-          kept_times[0] <= now - args.num_intervals:
+          kept_times[0] <= slot_now - (args.num_intervals + 1):
         kept_times.pop(0)
 
-    intervals = [False] * args.num_intervals
+    intervals = [False] * (args.num_intervals + 1)
     for kept_time in kept_times:
-        intervals[now - kept_time] = True
+        intervals[slot_now - kept_time] = True
 
     logging.debug(intervals)
 
-    if not False in intervals:
-        if not error_state:
-            logging.warning("Entering error state!")
-            error_state = True
+    if not False in intervals[1:]:
+        if not error_state or time_now - last_alert_time > ALERT_INTERVAL:
+            last_alert_time = time_now
             feed_handler( create_msg("Log Alert",
                                      "&#9760;",
                                      args.logfile,
                                      "Number of errors exceeded!",
                                      lines) )
+        if not error_state:
+            logging.warning("Entering error state!")
+            error_state = True
+
     else:
         if error_state:
             logging.info("Leaving error state.")
             error_state = False
-            feed_handler( create_msg("Log Un-Alert",
-                                     "&#127774;",
-                                     args.logfile,
-                                     "Log is back to normal.",
-                                     lines) )