CentOS 7 开始默认使用Systemd作为开启启动脚本的管理工具，Shadowsocks则是当前比较受欢迎的科学上网工具，本文将介绍如何在 CentOS 下安装和配置 Shadowsocks 服务。
安装 pip
pip是 python 的包管理工具。在本文中将使用 python 版本的 shadowsocks，此版本的 shadowsocks 已发布到 pip 上，因此我们需要通过 pip 命令来安装。
在控制台执行以下命令安装 pip：
curl "https://bootstrap.pypa.io/get-pip.py" -o "get-pip.py"
python get-pip.py
安装配置 shadowsocks
在控制台执行以下命令安装 shadowsocks：
pip install --upgrade pip
pip install shadowsocks
安装完成后，需要创建配置文件/etc/shadowsocks.json，内容如下：
{
"server": "0.0.0.0",
"server_port": 8388,
"password": "uzon57jd0v869t7w",
"method": "aes-256-cfb"
}
说明：
method为加密方法，可选aes-128-cfb, aes-192-cfb, aes-256-cfb, bf-cfb, cast5-cfb, des-cfb, rc4-md5, chacha20, salsa20, rc4, tableserver_port为服务监听端口password为密码，可使用密码生成工具生成一个随机密码
以上三项信息在配置 shadowsocks 客户端时需要配置一致，具体说明可查看 shadowsocks 的帮助文档。
配置自启动
新建启动脚本文件/etc/systemd/system/shadowsocks.service，内容如下：
[Unit]
Description=Shadowsocks
[Service]
TimeoutStartSec=0
ExecStart=/usr/bin/ssserver -c /etc/shadowsocks.json
[Install]
WantedBy=multi-user.target
执行以下命令启动 shadowsocks 服务：
systemctl enable shadowsocks
systemctl start shadowsocks
为了检查 shadowsocks 服务是否已成功启动，可以执行以下命令查看服务的状态：
systemctl status shadowsocks -l
如果服务启动成功，则控制台显示的信息可能类似这样：
● shadowsocks.service - Shadowsocks
Loaded: loaded (/etc/systemd/system/shadowsocks.service; enabled; vendor preset: disabled)
Active: active (running) since Mon 2015-12-21 23:51:48 CST; 11min ago
Main PID: 19334 (ssserver)
CGroup: /system.slice/shadowsocks.service
└─19334 /usr/bin/python /usr/bin/ssserver -c /etc/shadowsocks.json
Dec 21 23:51:48 morning.work systemd[1]: Started Shadowsocks.
Dec 21 23:51:48 morning.work systemd[1]: Starting Shadowsocks...
Dec 21 23:51:48 morning.work ssserver[19334]: INFO: loading config from /etc/shadowsocks.json
Dec 21 23:51:48 morning.work ssserver[19334]: 2015-12-21 23:51:48 INFO loading libcrypto from libcrypto.so.10
Dec 21 23:51:48 morning.work ssserver[19334]: 2015-12-21 23:51:48 INFO starting server at 0.0.0.0:8388
一键安装脚本
新建文件install-shadowsocks.sh，内容如下：
#!/bin/bash
# Install Shadowsocks on CentOS 7
echo "Installing Shadowsocks..."
random-string()
{
cat /dev/urandom | tr -dc 'a-zA-Z0-9' | fold -w ${1:-32} | head -n 1
}
CONFIG_FILE=/etc/shadowsocks.json
SERVICE_FILE=/etc/systemd/system/shadowsocks.service
SS_PASSWORD=$(random-string 32)
SS_PORT=8388
SS_METHOD=aes-256-cfb
SS_IP=`ip route get 1 | awk '{print $NF;exit}'`
GET_PIP_FILE=/tmp/get-pip.py
# install pip
curl "https://bootstrap.pypa.io/get-pip.py" -o "${GET_PIP_FILE}"
python ${GET_PIP_FILE}
# install shadowsocks
pip install --upgrade pip
pip install shadowsocks
# create shadowsocls config
cat <<EOF | sudo tee ${CONFIG_FILE}
{
"server": "0.0.0.0",
"server_port": ${SS_PORT},
"password": "${SS_PASSWORD}",
"method": "${SS_METHOD}"
}
EOF
# create service
cat <<EOF | sudo tee ${SERVICE_FILE}
[Unit]
Description=Shadowsocks
[Service]
TimeoutStartSec=0
ExecStart=/usr/bin/ssserver -c ${CONFIG_FILE}
[Install]
WantedBy=multi-user.target
EOF
# start service
systemctl enable shadowsocks
systemctl start shadowsocks
# view service status
sleep 5
systemctl status shadowsocks -l
echo "================================"
echo ""
echo "Congratulations! Shadowsocks has been installed on your system."
echo "You shadowsocks connection info:"
echo "--------------------------------"
echo "server: ${SS_IP}"
echo "server_port: ${SS_PORT}"
echo "password: ${SS_PASSWORD}"
echo "method: ${SS_METHOD}"
echo "--------------------------------"
执行以下命令一键安装：
chmod +x install-shadowsocks.sh
./install-shadowsocks.sh
也可以直接执行以下命令从 GitHub 下载安装脚本并执行：
bash <(curl -s http://morning.work/examples/2015-12/install-shadowsocks.sh)
安装完成后会自动打印出 Shadowsocks 的连接配置信息。比如：
Congratulations! Shadowsocks has been installed on your system.
You shadowsocks connection info:
--------------------------------
server: 10.0.2.15
server_port: 8388
password: RaskAAcW0IQrVcA7n0QLCEphhng7K4Yc
method: aes-256-cfb
--------------------------------
