如何通过ssh将ansible连接到两台Vagrant机器（Virtualbox Hypervisor）中？

我想通过ssh连接一台机器与另一台机器来执行ansible命令。我有一个CentOS7，想在OS内部连接到Ubuntu16 VM。

查看我的Vagrantfile和我尝试过的内容：

Vagrant.configure("2") do |config|
  config.vm.provider "virtualbox" do |vb|
     vb.gui = false
     vb.memory = "4096"
     vb.cpus = "4"
  end

  config.vm.define "centos7" do |centos7|
      centos7.vm.box = "centos/7"
      centos7.vm.hostname = "centos-vm"
      centos7.vm.network "public_network", ip: "192.168.0.105"
      #centos7.vm.network "forwarded_port", guest: 8080, host: 8888
      #centos7.vm.network "forwarded_port", guest: 22, host: 2222
      centos7.vm.provision "shell", run: "always", inline: <<-SHELL
         sudo route add default gw 192.168.0.1
         sudo yum update
         sudo yum -y install wget ntpdate net-tools nano firewalld telnet

         # Install java
         sudo yum -y install epel-release
         sudo yum install java-1.8.0-openjdk-devel
         java -version

         # isntall jenkins
         curl --silent --location http://pkg.jenkins-ci.org/redhat-stable/jenkins.repo | sudo tee /etc/yum.repos.d/jenkins.repo
         sudo firewall-cmd --permanent --zone=public --add-port=8080/tcp

         # Install ansible
         sudo yum -y install ansible

         # Install docker
         curl -fsSL https://get.docker.com/ | sh
         sudo usermod -aG docker $USER
         sudo systemctl start docker
         sudo systemctl status docker
         sudo systemctl enable docker
         sudo ps -ef | grep dockerd
      SHELL
  end

  config.vm.define "ubuntu16" do |ubuntu16|
      ubuntu16.vm.box = "ubuntu/xenial64"
      ubuntu16.vm.hostname = "ubuntu-vm"
      ubuntu16.vm.network "public_network", ip: "192.168.0.106"
      ubuntu16.vm.provision "shell", run: "always", inline: <<-SHELL
         sudo route add default gw 192.168.0.1
         # isntall python with virtuaenv
         sudo apt-get update
         sudo apt-get install build-essential libssl-dev libffi-dev python-dev
         sudo apt install python3-pip
         sudo pip3 install virtualenv
         virtualenv -p python3 env3
         . env3/bin/activate # or source env3/bin/activate which does exactly the same thing
         # you can make sure you are now working with Python 3
         python -- version
         which python
         deactivate
         sudo apt install wget ntpdate net-tools nano default-jdk -y
         sudo apt install apt-transport-https ca-certificates curl gnupg2 software-properties-common telnet -y
      SHELL
  end
end

当我尝试通过ssh连接时出现此错误：

[root@centos-vm vagrant]# ansible -m ping all
192.168.0.105 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: Permission denied (publickey,gssapi-keyex,gssapi-with-mic).",
    "unreachable": true
}
192.168.0.106 | UNREACHABLE! => {
    "changed": false,
    "msg": "Failed to connect to the host via ssh: Permission denied (publickey).",
    "unreachable": true
}
[root@centos-vm vagrant]# ssh 192.168.0.106
Permission denied (publickey).
[root@centos-vm vagrant]# cat /etc/ansible/hosts

[servers]
192.168.0.105
192.168.0.106

vagrant@ubuntu-vm:~/.ssh$ telnet 192.168.0.105 22
Trying 192.168.0.105...
Connected to 192.168.0.105.
Escape character is '^]'.
SSH-2.0-OpenSSH_7.4
^C^C^C
Connection closed by foreign host.

[vagrant@centos-vm .ssh]$ telnet 192.168.0.106
Trying 192.168.0.106...
Connected to 192.168.0.106.
Escape character is '^]'.
SSH-2.0-OpenSSH_7.2p2 Ubuntu-4ubuntu2.8
^C^C^C
Connection closed by foreign host.

我应该在Centos VM上进行任何设置吗？或者如果我必须让原始Vagrantfile的一些默认配置。我自己研究了文档。

更新：将第二个发行版更改为Ubuntu 16 LTS，因为盒子Debian 10在从仓库中获取软件包时出现了很多错误。