# 1) Install new binary.

# 2) Send a USR2 signal to the current pid file.
# This causes nginx master process that was running to rename its pid and start the new binary.
# Both will run simultaneously.
#

OLDPID=`cat /path/to/nginx/logs/pid.txt`
echo "OLDPID: $OLDPID"
sudo kill -USR2 $OLDPID

# 3) Check the new pid is running.

ps auxww | fgrep nginx | fgrep 'master process'

# 4) Send a WINCH to the old process.
# This disables the old workers.
sudo kill -WINCH $OLDPID

# Again, check web works.

# 5) Kill the old workers.
sudo kill -QUIT $OLDPID

# 6) Terminate the old master process, if still running (shouldn't be).
sudo kill -TERM $OLDPID