Setup shadowsocks on debian

setup-shadowsocks-on-debian.sh

#!/bin/bash

########## Install Shadowsocks ##########
# https://github.com/shadowsocks/shadowsocks-libev#debian--ubuntu

sh -c 'printf "deb http://httpredir.debian.org/debian jessie-backports main" > /etc/apt/sources.list.d/jessie-backports.list'
apt update
apt -t jessie-backports install shadowsocks-libev



########## Setup Shadowsocks ##########

# How to generate random string: <https://gist.github.com/earthgecko/3089509>
# And the `tr: Illegal byte sequence` issue:
# <http://unix.stackexchange.com/questions/45404/why-cant-tr-read-from-dev-urandom-on-osx>
random_pass=$(LC_CTYPE=C tr -dc 'a-zA-Z0-9' < /dev/urandom | fold -w 16 | head -n 1)

ss_config="{
  \"server\":\"0.0.0.0\",
  \"server_port\":8388,
  \"local_port\":1080,
  \"password\":\"$random_pass\",
  \"timeout\":300,
  \"method\":\"aes-256-cfb\"
}
"

# Remember to add the quotes around the variable otherwise
# you won't see the newline characters.

echo "$ss_config" > /etc/shadowsocks-libev/config.json


########## Optimizing Shadowsocks ##########
# <https://github.com/shadowsocks/shadowsocks/wiki/Optimizing-Shadowsocks>


cat <<EOT > /etc/sysctl.d/local.conf
# max open files
fs.file-max = 51200
# 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
# turn on TCP Fast Open on both client and server side
net.ipv4.tcp_fastopen = 3
# 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

# for high-latency network
net.ipv4.tcp_congestion_control = hybla

# for low-latency network, use cubic instead
# net.ipv4.tcp_congestion_control = cubic
EOT

sysctl --system

#instead of ulimit -n 51200
#we modify the environment var of the service unit
sed -i "s/MAXFD=.*/MAXFD=51200/g" /etc/default/shadowsocks-libev

# Restart shadowsocks server service
systemctl restart shadowsocks-libev

echo
echo -e "Your shadowsocks config file is at: '/etc/shadowsocks-libev/config.json', and your config is: \n$ss_config"
echo -e "Modify firewall rules, if necessary, using the following commands:"
echo -e "   iptables -I INPUT -p tcp --dport 8388 -j ACCEPT"
echo -e "   iptables -I INPUT -p udp --dport 8388 -j ACCEPT"