HAproxy softreload

/usr/lib/systemd/system/haproxy.service

[Unit]
Description=HAProxy Load Balancer
After=syslog.target network.target
[Service]
User=root
ExecStart=/etc/init.d/haproxy start_systemd
ExecStop=/etc/init.d/haproxy stop_systemd
ExecReload=/etc/init.d/haproxy reload_systemd
#Restart=on-abnormal
Type=forking
[Install]
WantedBy=multi-user.target

/etc/init.d/haproxy

#!/bin/bash -x

function TEMPFILE() {
        case $1 in
                create) mktemp
                        ;;
                delete)
                        rm -fr $2
                        ;;
        esac
}

function SETUP_QDISC() {
    # Set up the queuing discipline
    tc qdisc add dev lo root handle 1: prio bands 4
    tc qdisc add dev lo parent 1:1 handle 10: pfifo limit 1000
    tc qdisc add dev lo parent 1:2 handle 20: pfifo limit 1000
    tc qdisc add dev lo parent 1:3 handle 30: pfifo limit 1000

    # Create a plug qdisc with 1 meg of buffer
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: plug --limit 1048576
    # Release the plug
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: --update plug --release-indefinite

    # Set up the filter, any packet marked with "1" will be
    # directed to the plug
    tc filter add dev lo protocol ip parent 1:0 prio 1 handle 1 fw classid 1:4
}

function SOFT_RELOAD_HA() {
    /usr/local/sbin/haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf $(/bin/cat /var/run/haproxy.pid)
}

function RELOAD_IPTABLES() {
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: --update plug --buffer
    SOFT_RELOAD_HA
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: --update plug --release-indefinite
}

function ADD_IP_PLUG_QUEUE() {
    iptables -t mangle -I OUTPUT -p tcp -s $1 --syn -j MARK --set-mark 1
}


function KILL_HA_OLDPIDS() {
    /bin/sleep 15
    /bin/kill $(/bin/ps -ef | /bin/grep "haproxy -D -f /etc/haproxy/haproxy.cfg -p /var/run/haproxy.pid -sf" | /bin/grep -v grep  | /bin/awk '{print $2}')
}

function IPTABLES_HA_RELOAD() {
    iptables -I INPUT -p tcp --dport 16000 --syn -j DROP
    sleep 0.2
    SOFT_RELOAD_HA
    iptables -D INPUT -p tcp --dport 16000 --syn -j DROP
    sleep 1
    KILL_HA_OLDPIDS
}

function QDISC_HA_RELOAD() {
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: --update plug --buffer &> /dev/null
    SOFT_RELOAD_HA
    nl-qdisc-add --dev=lo --parent=1:4 --id=40: --update plug--release-indefinite &> /dev/null
    sleep 0.100
    # KILL_HA_OLDPIDS
}

if [ $# -ne 1 ]
then
  /bin/echo erro
  exit 1
else
  case $1 in
    start_systemd)
      SETUP_QDISC
      ADD_IP_PLUG_QUEUE <local interface ip>
      ADD_IP_PLUG_QUEUE <local interface ip>
      SOFT_RELOAD_HA
      ;;
    reload_systemd)
      QDISC_HA_RELOAD
      ;;
    setup)
      SETUP_QDISC
      ADD_IP_PLUG_QUEUE <local interface ip>
      ADD_IP_PLUG_QUEUE <local interface ip>
      ;;
    stop_systemd)
      killall haproxy
      ;;
    start)
      systemctl start haproxy
      ;;
    stop)
      systemctl stop haproxy
      ;;
    restart)
      systemctl restart haproxy
      ;;
    reload)
      systemctl restart haproxy
      ;;
    status)
      systemctl status haproxy
      ;;
  esac
fi