Before continuing, you need an inventory file. The default place for such a file is /etc/ansible/hosts. However, you can configure ansible to look somewhere else, use an environment variable (ANSIBLE_INVENTORY), or use the -i flag in ansible commands an provide the inventory path.

We've created an inventory file for you in the directory that looks like this:

host0 ansible_host=192.168.33.10 ansible_user=root
host1 ansible_host=192.168.33.11 ansible_user=root
host2 ansible_host=192.168.33.12 ansible_user=root

ansible_host is a special variable that sets the IP ansible will use when trying to connect to this host. It's not necessary here if you use the vagrant-hostmaster gem. Also, you'll have to change the IPs if you have set up your own virtual machines with different addresses.

ansible_user is another special variable that tells ansible to connect as this user when using ssh. By default ansible would use your current username, or use another default provided in ~/.ansible.cfg (remote_user).

Now that ansible is installed, let's check everything works properly.

ansible -m ping all -i step-01/hosts

What ansible will try to do here is just executing the ping module (more on modules later) on each host.

The output should look like this:

host0 | success >> {
    "changed": false,
    "ping": "pong"
}

host1 | success >> {
    "changed": false,
    "ping": "pong"
}

host2 | success >> {
    "changed": false,
    "ping": "pong"
}

Good! All 3 hosts are alive and kicking, and ansible can talk to them.

Now head to next step in directory step-02.