init_debian_stretch.sh

#!/bin/bash

## sysctl

init_sysctl() {
    cat << EOF > /etc/sysctl.d/local.conf
# max open files
fs.file-max = 1024000
# max read buffer
net.core.rmem_max = 67108864
# max write buffer
net.core.wmem_max = 67108864
# default read buffer
net.core.rmem_default = 65536
# default write buffer
net.core.wmem_default = 65536
# max processor input queue
net.core.netdev_max_backlog = 4096
# max backlog
net.core.somaxconn = 4096

# resist SYN flood attacks
net.ipv4.tcp_syncookies = 1
# reuse timewait sockets when safe
net.ipv4.tcp_tw_reuse = 1
# turn off fast timewait sockets recycling
net.ipv4.tcp_tw_recycle = 0
# short FIN timeout
net.ipv4.tcp_fin_timeout = 30
# short keepalive time
net.ipv4.tcp_keepalive_time = 1200
# outbound port range
net.ipv4.ip_local_port_range = 10000 65000
# max SYN backlog
net.ipv4.tcp_max_syn_backlog = 4096
# max timewait sockets held by system simultaneously
net.ipv4.tcp_max_tw_buckets = 5000
# TCP receive buffer
net.ipv4.tcp_rmem = 4096 87380 67108864
# TCP write buffer
net.ipv4.tcp_wmem = 4096 65536 67108864
# turn on path MTU discovery
net.ipv4.tcp_mtu_probing = 1

net.ipv4.tcp_congestion_control = htcp
# forward ipv4
net.ipv4.ip_forward = 1
EOF

    sysctl --system
}

## limits

init_limits() {
    sed -i 's/# End of file//g' /etc/security/limits.conf
    cat << EOF >> /etc/security/limits.conf
*               soft    nofile           512000
*               hard    nofile          1024000

# End of file
EOF
    cat << EOF >> /etc/profile
ulimit -SHn 1024000
EOF
}

## lotServer

prepare_lotServer() {
    # backup apt souce list
    cp /etc/apt/sources.list /etc/apt/sources.list.bak
    # downgrade kernel
    wget -N --no-check-certificate https://moeclub.org/attachment/LinuxShell/Debian_Kernel.sh
    apt install ethtool bc
    bash Debian_Kernel.sh
    # need to reboot and go on with init_lotServer
    #sed -i 's/256 2048/512 4096/g' /serverspeeder/etc/config
}

init_lotServer() {
    wget -N --no-check-certificate https://git.io/lotServerInstall.sh
    bash lotServerInstall.sh install
    sed -i 's/256 2048/512 4096/g' /appex/etc/config
    sed -i 's/maxmode="0"/maxmode="1"/g' /appex/etc/config
    /appex/bin/lotServer.sh restart
}

## check root
check_root() {
    if [[ $EUID -ne 0 ]]; then
       echo "This script must be run as root" 1>&2
       exit 1
    fi
}

process() {
    check_root    

    echo "init sysctl..."
    init_sysctl
    echo "done."

    echo "init limits..."
    init_limits
    echo "done."

    echo "prepare lotServer..."
    prepare_lotServer
    echo "done."

    echo "please reboot."
}

if [ x$1 != x ]; then
    case $1 in
        init_lot)
            init_lotServer
            ;;
        process)
            process
            ;;
        ?)
            echo "usage: process|init_lot"
            ;;
    esac
else
    echo "default action: process"
    process
fi