Test Ansible playbooks with Vagrant

We normally use Ansible playbooks to configure servers in a cloud provider. When we develop those playbooks we need to test them locally. Thanks to Vagrant it is quite easy to start a virtual machine and run our playbooks against it.

There are two ways to achieve this:

• using Vagrant’s Ansible provisioning feature
• using the virtual machine like any other remote server

I'm going to explain the second option here.

First, let's create a virtual machine called, for example, tau. The Vagrantfile could be:

Vagrant.configure('2') do |config|
  config.vm.define 'tau' do |debian|
    debian.vm.box = 'debian/buster64'
    debian.vm.network :private_network, ip: '192.168.27.2'
    debian.vm.hostname = 'tau'
    debian.vm.provider 'virtualbox' do |vb|
      vb.memory = '2048'
      vb.cpus = 2
    end
  end
end

We can start the server with:

vagrant up

Now we have to add it to Ansible's inventory, but we need to know the ssh key Vagrant is using when we connect using vagrant ssh:

$ vagrant ssh-config
Host tau
  HostName 127.0.0.1
  User vagrant
  Port 2200
  UserKnownHostsFile /dev/null
  StrictHostKeyChecking no
  PasswordAuthentication no
  IdentityFile /Users/javiervidal/test/.vagrant/machines/tau/virtualbox/private_key
  IdentitiesOnly yes
  LogLevel FATAL

Interesting, we can use /Users/javiervidal/test/.vagrant/machines/tau/virtualbox/private_key in the inventory. We need to add a line like this:

tau ansible_host=192.168.27.2 ansible_port=22 ansible_ssh_user=vagrant ansible_ssh_private_key_file=/Users/javiervidal/test/.vagrant/machines/tau/virtualbox/private_key ansible_python_interpreter=/usr/bin/python3

And finally we can test that Ansible can connect to tau:

$ ansible tau -m ping   
tau | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

😀