在安装predis扩展之前先安装composer，安装教程在https://getcomposer.org/download/：
php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('SHA384', 'composer-setup.php') === 'c32408bcd017c577ce80605420e5987ce947a5609e8443dd72cd3867cc3a0cf442e5bf4edddbcbe72246a953a6c48e21') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php
php -r "unlink('composer-setup.php');"
接着把composer设置全局环境变量：
mv composer.phar /bin/composer
把composer镜像地址改为国内的会快很多，教程地址：http://pkg.phpcomposer.com/
composer config -g repo.packagist composer https://packagist.phpcomposer.com
然后开启php-pear，php-devel和php-redis扩展，我是直接用CentOS 的yum包来安装扩展：
yum -y install php70w-devel.x86_64
yum install php70w-pear.noarch
yum -y install php70w-pecl-redis.x86_64
安装完成后切换到你的网站根目录下，成功后如图所示：
composer require predis/predis
Using version ^1.1 for predis/predis
./composer.json has been updated
> php artisan clear-compiled
Loading composer repositories with package information
Updating dependencies (including require-dev)
- Installing predis/predis (v1.1.1)
Downloading: % predis/predis suggests installing ext-phpiredis (Allows faster serialization and deserialization of the Redis protocol)
Writing lock file
Generating autoload files
> php artisan optimize
接着就可以在你的Controller中使用 use Redis 来各种操作了。