Exercise 1.0: Exploring the lab environment

Step 1

In the VS Code terminal section, navigate to the networking-workshop directory.

[centos@ansible ~]$ cd networking-workshop/
[centos@ansible networking-workshop]$

Step 2

Run the ansible command with the --version command to look at what is configured:

[centos@ansible networking-workshop]$ ansible --version
ansible [core 2.12.4]
config file = /home/centos/.ansible.cfg
configured module search path = ['/home/centos/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
ansible python module location = /home/centos/.local/lib/python3.8/site-packages/ansible
ansible collection location = /home/centos/.ansible/collections:/usr/share/ansible/collections
executable location = /home/centos/.local/bin/ansible
python version = 3.8.12 (default, Mar 31 2022, 14:42:38) [GCC 4.8.5 20150623 (Red Hat 4.8.5-44)]
jinja version = 3.1.1
libyaml = True

Note: The Ansible version you see might differ from the above output

This command gives you information about the version of Ansible, location of the executable, version of Python, search path for the modules and location of the ansible configuration file.

Step 3

Use the cat command to view the contents of the ansible.cfg file.

[centos@ansible networking-workshop]$ cat ~/.ansible.cfg
[defaults]
connection = smart
timeout = 60
inventory = /home/centos/networking-workshop/lab_inventory/hosts
host_key_checking = False
private_key_file = /home/centos/.ssh/aws-private.pem
[centos@ansible networking-workshop]$

Note the following parameters within the ansible.cfg file:

• inventory: shows the location of the ansible inventory being used
• private_key_file: this shows the location of the private key used to login to devices (this won’t be present for UDF, we will use the default key)

Step 4

The scope of a play within a playbook is limited to the groups of hosts declared within an Ansible inventory. Ansible supports multiple inventory types. An inventory could be a simple flat file with a collection of hosts defined within it or it could be a dynamic script (potentially querying a CMDB backend) that generates a list of devices to run the playbook against.

In this lab you will work with a file based inventory written in the ini format. Use the cat command to view the contents of your inventory:

[centos@ansible networking-workshop]$ cat lab_inventory/hosts

The output will look similar to as follows:

[all:vars]
ansible_user=centos
ansible_ssh_pass=f5ansible
ansible_ssh_private_key_file=/home/centos/.ssh/aws-private.pem

[lb]
f5 ansible_host=10.1.20.7 ansible_user=admin private_ip=10.1.1.7 destination_ip=10.1.20.100 ansible_ssh_pass=f5ansible

[control]
ansible ansible_host=10.1.1.4 ansible_user=centos

[webservers]
host1 ansible_host=10.1.20.5 ansible_user=centos private_ip=10.1.1.5
host2 ansible_host=10.1.20.6 ansible_user=centos private_ip=10.1.1.6

Note that the IP addresses will be different in your environment.

Step 5

In the above output every [ ] defines a group. For example [webservers] is a group that contains the hosts host1 and host2.

Note: A group called all always exists and contains all groups and hosts defined within an inventory.

We can associate variables to groups and hosts. Host variables are declared/defined on the same line as the host themselves. For example for the host f5:

f5 ansible_host=10.1.20.7 ansible_user=admin private_ip=10.1.1.7 destination_ip=10.1.20.100 ansible_ssh_pass=f5ansible

• f5 - The name that Ansible will use. This can but does not have to rely on DNS
• ansible_host - The IP address that ansible will use, if not configured it will default to DNS
• ansible_user - The user ansible will use to login to this host, if not configured it will default to the user the playbook is run from
• private_ip - This value is not reserved by ansible so it will default to a host variable. This variable can be used by playbooks or ignored completely.
• destination_ip - This value is not reserved either, we are using it to define the Virtual Server IP we want.
• ansible_ssh_pass - The password ansible will use to login to this host, if not configured it will assume the user the playbook ran from has access to this host through SSH keys.

Does the password have to be in plain text? No, Red Hat Ansible Tower can take care of credential management in an easy to use web GUI or a user may use ansible-vault

Go back to the home directory

[centos@ansible networking-workshop]$ cd ~

You have finished this exercise. Click here to return to the lab guide