Exercise 1.6: Using the bigip_irule module

Objective

Demonstrate use of the BIG-IP irule module to add iRules to a BIG-IP and then attach the iRules to a virtual server.

Guide

Step 1

Create two dummy irules with the names ‘irule1’ and ‘irule2’

[centos@ansible ~]$ nano irule1

when HTTP_REQUEST {
       log local0. "Accessing iRule1"
}

Save the file

[centos@ansible ~]$ nano irule2

when HTTP_REQUEST {
       log local0. "Accessing iRule2"
}

Save the file

Step 2:

Use VS Code Explorer to create a new file called bigip-irule.yml.

The Ansible node is equipped with Visual Studio Code and can be accessed via UDF ACCESS Methods.

Step 3:

Ansible playbooks are YAML files. YAML is a structured encoding format that is also extremely human readable (unlike it’s subset - the JSON format).

Enter the following play definition into bigip-irule.yml:

---
- name: BIG-IP SETUP
  hosts: lb
  connection: local
  gather_facts: false

• The --- at the top of the file indicates that this is a YAML file.
• The hosts: f5, indicates the play is run only on the F5 BIG-IP device
• connection: local tells the Playbook to run locally (rather than SSHing to itself)
• gather_facts: no disables facts gathering. We are not using any fact variables for this playbook.

Save and Exit out of editor.

Step 4

Next, add the vars and tasks stanzas. This task will use the bigip-irule to add irules to the BIG-IP.

vars:
 irules: ['irule1','irule2']

tasks:

- name: ADD iRules
  bigip_irule:
    provider:
      server: "{{private_ip}}"
      user: "{{ansible_user}}"
      password: "{{ansible_ssh_pass}}"
      server_port: 8443
      validate_certs: no
    module: "ltm"
    name: "{{item}}"
    content: "{{lookup('file','{{item}}')}}"
  with_items: "{{irules}}"

A play is a list of tasks. Tasks and modules have a 1:1 correlation. Ansible modules are reusable, standalone scripts that can be used by the Ansible API, or by the ansible or ansible-playbook programs. They return information to ansible by printing a JSON string to stdout before exiting.

• A variable 'irules' is a list defined with two irules => ‘irule1’ and irule2’
• name: ADD iRules is a user defined description that will display in the terminal output.
• bigip_irule: tells the task which module to use.
• The server: "{{private_ip}}" parameter tells the module to connect to the F5 BIG-IP IP address, which is stored as a variable private_ip in inventory
• The provider: parameter is a group of connection details for the BIG-IP.
• The user: "{{ansible_user}}" parameter tells the module the username to login to the F5 BIG-IP device with
• The password: "{{ansible_ssh_pass}}" parameter tells the module the password to login to the F5 BIG-IP device with
• The server_port: 8443 parameter tells the module the port to connect to the F5 BIG-IP device with
• The module: ltm paramters tells the module which BIG-IP module(ltm) the iRule is for
• The name: "{{item}}" parameter tells the module to create an iRule with the name ‘irule1’ and ‘irule2’
• The content: "{{lookup('file','{{item}}')}}" parameter tells the module what content to add to the iRule using the lookup plugin
• The validate_certs: "no" parameter tells the module to not validate SSL certificates. This is just used for demonstration purposes since this is a lab.
• loop: tells the task to loop over the provided list. The list in this case is the list of iRules.

Do not exit the file yet.

Step 5

Next, append the task to above playbook. This task will use the bigip_virtual_server to add attach the iRules to a Virtual Server on the BIG-IP.

- name: ATTACH iRules TO VIRTUAL SERVER
  bigip_virtual_server:
    provider:
      server: "{{private_ip}}"
      user: "{{ansible_user}}"
      password: "{{ansible_ssh_pass}}"
      server_port: 8443
      validate_certs: no
    name: "vip"
    irules: "{{irules}}"

• irules: "{{irules}} is a list of irules to be attached to the virtual server ‘irule1’ and ‘irule2’

Details of BIG-IP virtual_Server module or reference bigip-virtual-server.yml

Save the file and exit out of editor.

Step 6

Run the playbook - exit back into the command line of the control host and execute the following:

[centos@ansible ~]$ ansible-playbook bigip-irule.yml

Playbook Output

[centos@ansible]$ ansible-playbook bigip-irule.yml

PLAY [BIG-IP SETUP] *********************************************************************************************************************************

TASK [ADD iRules] *********************************************************************************************************************************
changed: [f5] => (item=irule1)
changed: [f5] => (item=irule2)

TASK [ATTACH iRules TO VIRTUAL SERVER] **********************************************************************************************************************
changed: [f5]

PLAY RECAP *********************************************************************************************************************************
f5                         : ok=2    changed=2    unreachable=0    failed=0

Solution

The finished Ansible Playbook is provided here for an Answer key. Click here: bigip-irule.yml.

Verifying the Solution

To see the configured iRules and Virtual Server, login to the F5 load balancer.

In the Compnent tab On the BIG-IP click the ACCESS drop down then the TMUI link.

Login information for the BIG-IP: - username: admin - password: provided by instructor defaults to ansible

The list of iRules can be found by navigating the menu on the left. Click on Local Traffic-> iRules -> iRules List.

To view the Virtual Server click on Local Traffic-> Virtual Servers, click on the Virtual Server then click on the ‘resoruces’ tab and view the iRules attached to the Virtual Server

You have finished this exercise.