I have 4 VMs in my Vagrantfile - 3 application servers and an Ansible control host.

I only use Vagrant to create the VMs as I provision them manually from the ansible control host because I am still creating/editing the ansible scripts.

I can do vagrant ssh ansible and vagrant ssh app1/2/3 etc. but when I try to do ansible-playbook oracle.yml from the Ansible control host, SSH fails with

fatal: []: UNREACHABLE! => {"changed": false, "msg": "SSH encountered an unknown error during the connection. We recommend you re-run the command using -vvvv, which will enable SSH debugging output to help diagnose the issue", "unreachable": true}

I can successfully ssh from the Ansible VM to the Oracle VM using user vagrant and password vagrant.

The key parts of my Vagrantfile are:

config.ssh.insert_key = false

config.vm.define "db" do |db|
    db.vm.box = "boxcutter/ol67"
    db.vm.hostname = "oracle-vm"
    db.vm.network "forwarded_port", guest: 22, host: 2201, id: "ssh", auto_correct: false
    db.vm.network "forwarded_port", guest: 1521, host: 1521
    db.vm.network "private_network", ip: ""
    db.vm.provider "virtualbox" do |v|
        v.name = "oracle-vm"
        v.linked_clone = true
        v.memory = 2048
        v.cpus = 2

#Optional ansible control machine for Windows users
config.vm.define "ansible", autostart: false do |ansible|
    ansible.vm.box = "williamyeh/ansible"
    ansible.vm.hostname = "ansible-vm"
    ansible.vm.network "forwarded_port", guest: 22, host: 2204, id: "ssh", auto_correct: false
    ansible.vm.network "private_network", ip: ""
    ansible.vm.provider "virtualbox" do |v|
        v.linked_clone = true
    #Mount the project directory on the guest so we can run the playbooks from there
    ansible.vm.synced_folder ".", "/data/ansible", create: true

What do I need to put in the Vagrantfile to allow the Ansible VM to connect to the other VMs without requiring a password or extra manual steps after vagrant up?

This is just for development testing on a private network on developers PCs so security is not really an issue and comes second to ease of implementation and smooth user experience.

  • 1
    Duplicate of devops.stackexchange.com/questions/1017/… Commented May 25, 2017 at 0:47
  • I stated quite clearly that I can ssh between VMs it is just that ansible cannot because it requires keys set up. He cannot ssh. The questions are clearly different.
    – opticyclic
    Commented May 25, 2017 at 2:34
  • @JamesShewey: I don't think that any answer for that question is relevant to that. The answer given refers to communications from the host to the guests; the needed answer needs to apply between guests. Commented Mar 15, 2018 at 0:36

4 Answers 4


There is no general method and it might depend on how boxcutter/ol67 was packed.

  1. The easiest method would be to define the password in the Ansible inventory file:

  2. The second method would be to leave the insecure private key configured on the oracle-vm machine and inject the private key to the ansible VM:

    config.vm.provision "shell" do |s|
      ssh_insecure_key = File.readlines("#{Dir.home}/.vagrant.d/insecure_private_key").first.strip
      s.inline = <<-SHELL
        echo #{ssh_insecure_key} >> /home/vagrant/.ssh/id_rsa
        chown vagrant /home/vagrant/.ssh/id_rsa
        chmod 400 /home/vagrant/.ssh/id_rsa
  3. Generate the key pair beforehand on the host machine, inject private key to Ansible VM, public key to Oracle's authorized_keys.

  4. Generate the key pair on Ansible VM, copy the public key to Oracle VM using shell provisioner and inject vagrant as password for ssh-copy-id.

And the list does not end here, it depends on required security.


Based on techraf's 3rd suggestion I did the following:

  • vagrant up ansible
  • ssh-keygen (no password just pressed Enter)
  • copied .ssh/id_rsa and .ssh/id_rsa.pub to the project directory
  • vagrant destroy ansible
  • modified the Vagrantfile to copy the id_rsa to all hosts
  • modified the Vagrantfile to copy the id_rsa.pub into authorized_keys on all hosts
  • modified the Vagrantfile to disable host checking

Vagrantfile snippet:

 config.vm.provision "file", source: "id_rsa", destination: "/home/vagrant/.ssh/id_rsa"
 public_key = File.read("id_rsa.pub")
 config.vm.provision :shell, :inline =>"
     echo 'Copying ansible-vm public SSH Keys to the VM'
     mkdir -p /home/vagrant/.ssh
     chmod 700 /home/vagrant/.ssh
     echo '#{public_key}' >> /home/vagrant/.ssh/authorized_keys
     chmod -R 600 /home/vagrant/.ssh/authorized_keys
     echo 'Host 192.168.*.*' >> /home/vagrant/.ssh/config
     echo 'StrictHostKeyChecking no' >> /home/vagrant/.ssh/config
     echo 'UserKnownHostsFile /dev/null' >> /home/vagrant/.ssh/config
     chmod -R 600 /home/vagrant/.ssh/config
     ", privileged: false
  • This solution worked well for me but I had to change Host 192.168.*.* to just *. Not sure why. Thanks!
    – Zacho
    Commented Oct 2, 2018 at 19:04

If you want to have a preformatted block within a list, indent by eight spaces:

  1. generate public/private key

    cd vagrant-home
    ssh-keygen // just pressed enter
    copy ~/.ssh/id_rsa .
    copy ~/.ssh/id_rsa.pub .
  2. edit Vagrantfile,add follow lines: config.vm.provision "file", source: "id_rsa", destination: "/home/vagrant/.ssh/id_rsa"

        public_key = File.read("id_rsa.pub")
        config.vm.provision "shell", inline: <<-SCRIPT
            chmod 600 /home/vagrant/.ssh/is_rsa
            echo 'Copying ansible-vm public SSH Keys to the VM'
            #mkdir -p /home/vagrant/.ssh
            chmod 700 /home/vagrant/.ssh
            echo '#{public_key}' >> /home/vagrant/.ssh/authorized_keys
            chmod -R 600 /home/vagrant/.ssh/authorized_keys
            echo 'Host 192.168.*.*' >> /home/vagrant/.ssh/config
            echo 'StrictHostKeyChecking no' >> /home/vagrant/.ssh/config
            echo 'UserKnownHostsFile /dev/null' >> /home/vagrant/.ssh/config
            chmod -R 600 /home/vagrant/.ssh/config
  3.         vagrant up // or vagrant reload --provision
  • Is this just a reformatted version of my answer? If so you should probably just edit my answer rather than adding a new one.
    – opticyclic
    Commented Aug 21, 2018 at 17:14

You could generate the keys using shell provisioner ssh-keygen quiet mode, copy the pub key to the project folder and then copy it to the other(s) machine(s) using file provisioner. Assuming /vagrant/ is the project synced folder, it should be something like this:

machine1.vm.provision "shell", inline: "[ ! -f '/home/vagrant/.ssh/id_rsa' ] && ssh-keygen -q -f /home/vagrant/.ssh/id_rsa -N ''"

machine1.vm.provision "shell", inline: "cp /home/vagrant/.ssh/id_rsa.pub /vagrant/"

machine2.vm.provision "file", source: "id_rsa.pub", destination: "/home/vagrant/.ssh/"

machine2.vm.provision "shell", inline: "[ ! -f '/home/vagrant/.ssh/id_rsa_machine1.pub' ] && cat /vagrant/id_rsa.pub >> /home/vagrant/.ssh/authorized_keys"

machine2.vm.provision "file", source: "id_rsa.pub", destination: "/home/vagrant/.ssh/id_rsa_machine1.pub"

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.