master: Warning: Authentication failure. Retrying...

报错信息：

使用的认证方法是密钥形式，修改成使用密码形式。
在Vagrantfile配置文件中添加了两行代码，使用明文用户名密码
config.ssh.username = “vagrant”
config.ssh.password = “vagrant”

 # Don't attempt to update Virtualbox Guest Additions (requires gcc)
    if Vagrant.has_plugin?("vagrant-vbguest") then
      config.vbguest.auto_update = false
    end
    # Finally, fall back to VirtualBox
    config.vm.provider :virtualbox do |v, override|
      setvmboxandurl(override, :virtualbox)
      v.memory = vm_mem # v.customize ["modifyvm", :id, "--memory", vm_mem]
      v.cpus = $vm_cpus # v.customize ["modifyvm", :id, "--cpus", $vm_cpus]

      config.ssh.username = "vagrant"
      config.ssh.password = "vagrant"

      # Use faster paravirtualized networking
      v.customize ["modifyvm", :id, "--nictype1", "virtio"]
      v.customize ["modifyvm", :id, "--nictype2", "virtio"]
    end

重新启动日志：