谈谈Vagrant中的那些坑：CentOS

安装了vagrant之后，当然需要将它投入使用。由于计划中的生产环境是 CentOS 7，因此想搭建一个 基于CentOS 7（x86_64）的虚拟开发环境。

最开始的一系列工作，比如在vbox中安装CentOS 7、打包box文件、将box导入vagrant等都不在此一一细述，后面将有专文总结这些过程。

然后坑来了：修改Vagrantfile配置文件欲实现 public_network：

config.vm.network "public_network", ip: "192.168.0.6"

然后 vagrant up 启动虚拟机：

$ vagrant up
==> default: Attempting graceful shutdown of VM...
==> default: Clearing any previously set forwarded ports...
==> default: Clearing any previously set network interfaces...
==> default: Preparing network interfaces based on configuration...
    default: Adapter 1: nat
    default: Adapter 2: bridged
==> default: Forwarding ports...
    default: 22 (guest) => 2222 (host) (adapter 1)
==> default: Booting VM...
==> default: Waiting for machine to boot. This may take a few minutes...
    default: SSH address: 127.0.0.1:2222
    default: SSH username: vagrant
    default: SSH auth method: private key
    default: Warning: Connection reset. Retrying...
C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:54:in `readpartial': An established connection was aborted by the software in your host machine. (Errno::ECONNABORTED)
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:54:in `block (2 levels) in negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:52:in `loop'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:52:in `block in negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:50:in `loop'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:50:in `negotiate!'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/server_version.rb:32:in `initialize'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/session.rb:84:in `new'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh/transport/session.rb:84:in `initialize'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh.rb:233:in `new'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/net-ssh-4.1.0/lib/net/ssh.rb:233:in `start'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:397:in `block (2 levels) in connect'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:88:in `block in timeout'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `block in catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:103:in `timeout'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:371:in `block in connect'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/lib/vagrant/util/retryable.rb:17:in `retryable'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:370:in `connect'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:68:in `block in wait_for_ready'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:88:in `block in timeout'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `block in catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:32:in `catch'
        from C:/HashiCorp/Vagrant/embedded/lib/ruby/2.2.0/timeout.rb:103:in `timeout'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/plugins/communicators/ssh/communicator.rb:46:in `wait_for_ready'
        from C:/HashiCorp/Vagrant/embedded/gems/gems/vagrant-1.9.4/lib/vagrant/action/builtin/wait_for_communicator.rb:16:in `block in call'

就这么出错了。Guest已经启动，可以通过 vagrant ssh 连接，但错误的结果导致不能在已启动的 vagrant box 中共享主机文件，这可是个大问题。先后许多天，一直陷在这个巨坑里，从 vagrant 配置、插件，到 CentOS 7 Guest 的配置，想尽了各种办法，始终无法解决这个问题。从网上搜集到的办法主要是针对 Ubuntu Guest 的，依照做了之后都不起作用。

绝望之余，又想起了 vagrant plugin，有没有一个插件能解决这个问题呢？ 到 Ruby Gems去查找 Vagrant Centos，果然找到一个： vagrant-centos7_fix (version 0.0.1)，描述为：Uses Fedora network scripts on CentOS 7.看来这是用来解决CentOS7网络问题的啊。带着希望安装了这个插件：

$ vagrant plugin install vagrant-centos7_fix

但是并没有能解决问题。再一细看，这个插件已经是2014年1月11日发布的，距今已三年多。期间 vagrant 的版本不断升级，如果有什么问题的话应该早已经解决了。

但是这个插件的出现给我一个提示：是否CentOS 7原生地存在着在 vagrant 中的这些问题呢？带着这个疑问，其后试验性安装 Ubuntu、Fedora等Linux发行版，都没有任何问题。看来只有放弃了，换一种吧。由于CentOS与Fedora同出一门，因此就选用Fedora作为开发平台吧，毕竟是兄弟，使用上与CentOS差别不大。其后直接换用 Fedora 25 Server，顺利编译安装配置了 MySQL 5.7.18、Apache 2.4.25、PHP 7.1.4，虚拟开发环境很快地搭建起来。

当然，如果坚持要使用 CentOS 7 作为 Vagrant 的Guest端的话，你必须从两者中选择一个：要么不使用 bridged network，要么不映射主机共享文件夹到Guest中。