How to Automate Daily Nginx Log Rotation with a Bash Script

nginx's log file does not rotate automatically, so a single large file can become hard to manage under high traffic.

Idea

At midnight rename the current log file to include the date, then create a new log file. Use a scheduled task (cron) to run a script that performs the rename and signals the Nginx master process with the USR1 signal to reopen logs.

Implementation

#/bin/bash

# Path to backup logs
bakpath='/home/nginx/logs'

# Path to nginx logs
logpath='/usr/local/nginx/logs'

# Create year/month subdirectory in backup path
mkdir -p $bakpath/$(date +%Y)/$(date +%m)

# Move and rename access log
mv $logpath/access.log $bakpath/$(date +%Y)/$(date +%m)/access.$(date +%Y%m%d).log

# Move and rename error log
mv $logpath/error.log $bakpath/$(date +%Y)/$(date +%m)/error.$(date +%Y%m%d).log

# Send USR1 signal to nginx to reopen logs
kill -USR1 `cat /usr/local/nginx/logs/nginx.pid`

Schedule this script to run at 00:00 daily via crontab to maintain manageable log files.