Stop sidekiq, but first wait until it finishes all the running jobs

stop_sidekiq.sh

#!/bin/bash

RETRY_FREQUENCY=5
MAX_TRIES=100
PIDFILE=/var/www/app/current/tmp/pids/sidekiq.pid

# Helper function for printing logs with timestamp
echo_time() {
    date +"[%H:%M:%S] [Sidekiq-smart-restart] $*"
}

if [ ! -f $PIDFILE ]; then
    echo_time 'PID file not found'
    exit 1
fi

PID=`cat $PIDFILE`
ps --pid $PID 2>&1 > /dev/null 
if [ $? -eq 1 ]; then
  echo_time "Sidekiq process does not exist"
  exit 1
fi

# First, let's make sure that sidekiq does not pick up more jobs
echo_time "TSTP signal - Ask sidekiq to not pick up more jobs"
kill -TSTP $PID 2>&1 > /dev/null

# Now, let's wait until it finishes all the jobs and then send a TERM signal to it
for ((i=1; i<=$MAX_TRIES; i++))
do
    IS_SIDEKIQ_DONE=$(ps -f --pid $PID | grep -v PID | grep -E "\[0 of [0-9]+ busy\]" > /dev/null)$?
    if [ $IS_SIDEKIQ_DONE -eq 0 ]; then
	echo_time "Sidekiq is done with its jobs"
	break
    else
	echo_time "Sidekiq is still busy"
	sleep $RETRY_FREQUENCY
    fi
    if [ $i -eq $MAX_TRIES ]; then
	echo_time "Can't wait any longer, maximum number of retries reached"
    fi
done

echo_time "TERM signal - Shutting down sidekiq"
kill -TERM $PID 2>&1 > /dev/null