Today I was asked to help with a request from our voice engineer. She on occasion has to run debugs for specific call functions on our ISR 4K routers, which show up in the buffered log. We tried sending those log entries to our syslog server, but since the transport protocol was udp/514 (default), some of the messages were coming in out of order. We tried a second syslog server and got the same result.
Another option was to use tcp instead, so we attempted to get that working. Unfortunately the syslog server was not listening on that port, so we had to improvise. We came up with the idea of exporting the full log file to an ftp server every so often, and using EEM to accomplish this.
Our initial script runs as a privilege 15 user once per day, and uses a while loop to run every 60 minutes of 3600 seconds. It simply dumps the entire log buffer into a text file with a variable which increments once per hour.
event manager session cli username "neteng" privilege 15
event manager applet syslog_redirect
event timer cron cron-entry "0 0 * * *" maxrun 86400
action 0.00 cli command "term len 0"
action 0.01 set i "0"
action 0.02 while $i le 23
action 0.03 cli command "show log | redirect ftp://10.10.10.10/logs/$i.txt"
action 0.04 increment i 1
action 0.05 wait 3600
action 0.06 end
This worked pretty well, and we saw the script running once per hour as expected. Unfortunately the log buffer is set to 70000000 (due to the large volume of debug entries written for each call), so writing the files takes about 4-5 minutes. The script actually generates the log files at 12:04am, 1:08am, and so on. At first I was apprehensive about this and wanted the file to correspond to the variable integer, but found that we were looking at the timestamp of the file rather than the filename itself.
Overall, a very basic script that does what we wanted. However, it sometimes gets stuck we have to ask the question, why the hell are we letting a process run for 24 hours? That eats up cpu/memory cycles. Here is a better version:
event manager applet syslog_redirect
event timer cron cron-entry "0 * * * *"
action 0.0 cli command "show clock"
action 0.1 string range "$_cli_result" 2 4
action 0.2 set hour "$_string_result"
action 0.3 string range "$_cli_result" 6 7
action 0.4 set mins "$_string_result"
action 0.5 string range "$_cli_result" 20 22
action 0.6 set day "$_string_result"
action 0.7 cli command "show log | redirect ftp://10.13.5.36/vgw/test/$day$hour.$mins.txt"
action 0.8 cli command "clear log" pattern "confirm"
action 0.9 cli command "yes"
It will even clear the log after running, making your next log dumps smaller in size. Depending on your "show clock" output, you may need to adjust the numerical variables on the right, as they are literal positions within the output itself.
