Set up a Basic Ansible Lab

This article outlines the process for managing a switch using Ansible in a lab environment. This example is showing off Ansible’s ad-hoc commands. For repeated tasks, use an Ansible playbook; like this easy playbook example.

Requirements

• One switch running Cumulus Linux (any version), called switch1
• A server or virtual machine running Debian, with a basic installation (default packages only), called server1

On the server, set up the following:

• DHCP
• Ansible

Network Addresses

This example uses the 192.168.0.0/24 subnet.

Configure server1

Configure a DHCP server on the server, then install Ansible.

1. Install the required packages:

   root@server:~# apt-get install isc-dhcp-server
   

2. Assign the static IP address 192.168.0.2 to server1. Edit /etc/network/interfaces so it looks like:

   auto lo
   iface lo inet loopback
   
   auto eth0
   iface eth0 inet static
       address 192.168.0.2
       netmask 255.255.255.0
       gateway 192.168.0.1
   

3. Configure the DHCP scope. Edit /etc/dhcp/dhcpd.conf and add this to the file:

   subnet 192.168.0.0 netmask 255.255.255.0 {
       range 192.168.0.100 192.168.0.200
       option routers 192.168.0.1;
       option domain-name-server 192.168.0.2;
       option domain-name "example.com";
       
       host switch1 {
         hardware ethernet 00:JJ:YU:38:AC:45;
         fixed-address 192.168.0.10;
       }
   

4. Restart server1.

5. Reboot switch1.

6. Confirm that switch1 is reachable from server1:

    root@server:~# ping 192.168.0.10 
    64 bytes from 192.168.100.11: icmp_req=2 ttl=64 time=0.141 ms
   

7. Install Ansible:

   root@server:~# apt-get install python-pip
   root@server:~# pip install ansible
   

Configure a MOTD via Ansible

This section describes how to create a simple message of the day (MOTD) using Ansible.

1. Create a sample MOTD file:

    root@server:~#  echo "SAMPLE MOTD" > ~/sample.motd
   

2. Create an inventory file with switch1 in the list:

    root@server:~#  echo "192.168.0.10" > ~/ansible.hosts
   

3. Push the sample MOTD to switch1 (192.168.0.10). Enter the password for the cumulus user (the default user):

   root@server:~# ansible -k -K -u cumulus -i ~/ansible.hosts -m 'copy' -a 'src=~/sample.motd dest=/etc/motd' 192.168.0.10
        
       
   SSH password:
   sudo password [defaults to SSH password]: 
    sw1 | success >> {
       "changed": false, 
       "dest": "/etc/motd", 
       "gid": 0, 
       "group": "root", 
       "md5sum": "b04dde3768174a34f75fdde78142849d", 
       "mode": "0644", 
       "owner": "root", 
       "path": "/etc/motd", 
       "size": 12, 
       "state": "file", 
       "uid": 0
   }
   

See Also