09安装运行redis-trib.rb所需的环境

运行redis-trib.rb脚本配置Redis的cluster，需要安装ruby环境，这里采用源码安装：

1：下载源码包：

https://cache.ruby-lang.org/pub/ruby/2.2/ruby-2.2.3.tar.gz

2：解压安装：

tar xzvf ruby-2.2..tar.gz -C /root/redis
cd /root/redis/ruby-2.2./
./configure
make
make install

3：安装Ruby之后，因redis-trib.rb依赖于gem包redis，因此需要执行命令：gem  install redis，报错：

ERROR:  Loading command: install (LoadError)
        cannot load such file -- zlib
ERROR:  While executing gem ... (NoMethodError)
    undefined method `invoke_with_build_args' for nil:NilClass

解决方法：

apt-get install zlib1g-dev
cd /root/redis/ruby-2.2./ext/zlib
ruby ./extconf.rb
make
make install

4：再次执行命令gem  install  redis，再次报错：

ERROR:  While executing gem ... (Gem::Exception)
    Unable to require openssl, install OpenSSL and rebuild ruby (preferred) or use non-HTTPS sources

解决方法：

apt-get install libssl-dev
cd /root/redis/ruby-2.2./ext/openssl
ruby ./extconf.rb
ln -s /root/redis/ruby-2.2./include /
make
make install

5：再次执行命令gem  install  redis，竟然还是报错，错误信息是：

Errno::ECONNRESET: Connection reset by peer

查了一下原因，竟然是伟大的墙做的贡献(https://ruby.taobao.org/)，解决办法如下：

#gem sources --add https://ruby.taobao.org/ --remove https://rubygems.org/
https://ruby.taobao.org/ added to sources
https://rubygems.org/ removed from sources

#gem sources -l
*** CURRENT SOURCES ***

https://ruby.taobao.org/

6：再次执行命令gem  install  redis，终于成功，此时，就可以运行redis-trib.rb脚本了。