Some script i use to (re)spawn ztaskd instances

ztaskd.sh

#!/bin/bash
#set -x

website_instance=${1:-$USERNAME}
declare -A processes_to_monitor
my_pidfile="/tmp/$website_instance/ztask_monitor.pid"

source /srv/$website_instance/env/bin/activate
cd /srv/$website_instance/main/

function safe_kill_from_pidfile() {
    if [[ ! -f "$1" ]]; then
        return
    fi

    local pid="$(<$1)"

    if [[ -d /proc/$pid ]]; then
        echo kill $pid
        kill $pid
        while [[ -d /proc/$pid ]]; do
            sleep 1
        done
        echo $pid is dead
    fi
}

for client in $(find /srv/$website_instance/main/clients/* -maxdepth 0 -type d); do
    ztask_pidfile="/tmp/$website_instance/${client##*/}_ztask.pid"
    ztask_logfile="/var/log/$website_instance/${client##*/}_ztask.log"
    ztask_command="$client/manage.py ztaskd --noreload -f $ztask_logfile"

    processes_to_monitor[$ztask_pidfile]="$ztask_command"
done
unset ztask_pidfile
unset ztask_logfile
unset ztask_command

safe_kill_from_pidfile $my_pidfile
echo $$ > $my_pidfile

for pidfile in ${!processes_to_monitor[@]}; do
    safe_kill_from_pidfile $pidfile
    ${processes_to_monitor[$pidfile]} & disown && echo $! > $pidfile
done

while true; do
    for pidfile in ${!processes_to_monitor[@]}; do
        if [[ ! -f $pidfile || ! -d /proc/$(<$pidfile) ]]; then
            echo ztaskd process of $pidfile is gone, starting it again | mail root
            ${processes_to_monitor[$pidfile]} & disown && echo $! > $pidfile
            sleep 15
        fi
    done
done