You don’t need to write your own log rotation service in Linux, you can use the built in service called logrotate super easily.
Below is a directory listing inside a common /etc/logrotate dir. There are already be a bunch of existing services using logrotate already. Peak around them for examples if you’d like.
[email protected]:/etc/logrotate.d# ll total 100 drwxr-xr-x 2 root root 4096 Dec 15 09:50 ./ drwxr-xr-x 174 root root 12288 Dec 27 18:02 ../ -rw-r--r-- 1 root root 434 Mar 10 2015 apache2 -rw-r--r-- 1 root root 126 Mar 17 2015 apport -rw-r--r-- 1 root root 173 Apr 10 2014 apt -rw-r--r-- 1 root root 79 Feb 17 2014 aptitude -rw-r--r-- 1 root root 413 Dec 11 2015 cups-daemon -rw-r--r-- 1 root root 232 Mar 7 2014 dpkg -rw-r--r-- 1 root root 197 Dec 15 2015 haproxy -rw-r--r-- 1 root root 609 Jan 8 2015 landscape-client -rw-r--r-- 1 root root 686 Jun 23 2016 mysql-server -rw-r--r-- 1 root root 157 Feb 16 2016 pm-utils -rw-r--r-- 1 root root 94 Nov 25 2014 ppp -rw-r--r-- 1 root root 260 Mar 5 2014 rabbitmq-server -rw-r--r-- 1 root root 515 Dec 4 2013 rsyslog -rw-r--r-- 1 root root 513 Feb 19 2014 speech-dispatcher -rw-r--r-- 1 root root 339 Jun 8 2016 squid3 -rw-r--r-- 1 root root 178 Feb 28 2014 ufw -rw-r--r-- 1 root root 177 Dec 6 2013 unattended-upgrades -rw-r--r-- 1 root root 122 Apr 11 2014 upstart
Create a script in logrotate.d folder
Open up a new file in the /etc/logrotate.d directory, you can name it whatever you want, as long as there isn’t an existing file with the same name.
vi /etc/logrotate.d/mycustomservice
Contents of Basic mycustomservice Log Rotator
The log file name goes at the very top of the script, in this case /var/log/mycustomservice.log, followed by the params.
/var/log/mycustomservice.log
{
rotate 4
daily
missingok
notifempty
compress
delaycompress
sharedscripts
postrotate
endscript
}
That’s all there is to making your custom log rotator.
List of common Log Rotate params and their descriptions
See man page for more options.
| param | description |
|---|---|
| compress | Old versions of log files are compressed with gzip(1) by default. See also nocompress. |
| daily | Log files are rotated every day. |
| missingok | If the log file is missing, go on to the next one without issuing an error message. See also nomissingok. |
| notifempty | Do not rotate the log if it is empty (this overrides the ifempty option). |
| rotate count | Log files are rotated count times before being removed or mailed to the address specified in a mail directive. If count is 0, old versions are removed rather than rotated. |
| size size | Log files are rotated only if they grow bigger then size bytes. If size is followed by k, the size is assumed to be in kilobytes. If the M is used, the size is in megabytes, and if G is used, the size is in gigabytes. So size 100, size 100k, size 100M and size 100G are all valid. |
| delaycompress | Postpone compression of the previous log file to the next rotation cycle. This only has effect when used in combination with compress. It can be used when some program cannot be told to close its logfile and thus might continue writing to the previous log file for some time. |
| postrotate/endscript | The lines between postrotate and endscript (both of which must appear on lines by themselves) are executed (using /bin/sh) after the log file is rotated. These directives may only appear inside a log file definition. Normally, the absolute path to the log file is passed as first argument to the script. If sharedscripts is specified, whole pattern is passed to the script. See also prerotate. See sharedscripts and nosharedscripts for error handling. |
| sharedscripts | Normally, prerotate and postrotate scripts are run for each log which is rotated and the absolute path to the log file is passed as first argument to the script. That means a single script may be run multiple times for log file entries which match multiple files (such as the /var/log/news/* example). If sharedscripts is specified, the scripts are only run once, no matter how many logs match the wildcarded pattern, and whole pattern is passed to them. However, if none of the logs in the pattern require rotating, the scripts will not be run at all. If the scripts exit with error, the remaining actions will not be executed for any logs. This option overrides the nosharedscripts option and implies create option. |
