Task 1. Create an inventory

Let’s create a simple ansible inventory! For our lab we will use the main inventory file (/etc/ansible/hosts) with the following content:

[datacenter]
10.1.1.2
10.1.1.3
10.1.1.5
10.1.1.10
10.1.10.20
10.1.10.100

[bigip]
10.1.1.10       tmos_version=13.1
10.1.1.5        tmos_version=13.1
10.1.1.11       tmos_version=12.1

[webservers]
10.1.10.20      apache_version=2.6
10.1.10.100     apache_version=2.6
10.1.10.101
10.1.10.102
10.1.10.103

[production]
10.1.1.10
10.1.10.20
192.168.1.12

[lab]
10.1.1.3
10.1.1.5
192.168.2.11

[waf]
mywaf.f5demo.fch

This is as simple as that!!!

Besides being simple, this is really powerful in the defintion of targets:

• webservers:bigip is a logical OR operation so it corresponds to all IPs in these groups
• datacenter:!webservers means paris devices except webservers, so: *10.1.1.2,10.1.1.3
• bigip:&production is a logical intersection, so: 10.1.1.10
• datacenter:&bigip:!lab is a combinaison corresponding to 10.1.1.10

Although it is not recommended to add variables to the main inventory file we will do it for lab purpose only. In real life, we higly recommend using dedicated INI files such as:

• /etc/ansible/group_vars/bigip
• /etc/ansible/group_vars/webservers
• /etc/ansible/host_vars/mywaf.f5demo.fch

In order to check the inventory

$ ansible-inventory --list
{
    "_meta": {
        "hostvars": {
            "1.1.10.20": {},
            "10.1.1.10": {},
            "10.1.1.11": {},
            "10.1.1.2": {},
            "10.1.1.3": {},
            "10.1.1.5": {},
            "10.1.10.100": {
                "apache_version": 2.6
            },
            "10.1.10.101": {},
            "10.1.10.102": {},
            "10.1.10.103": {},
            "10.1.10.20": {
                "apache_version": 2.6
            },
            "192.168.1.12": {},
            "192.168.2.11": {},
            "mywaf.f5demo.fch": {}
        }
    },
    "all": {
        "children": [
            "bigip",
            "datacenter",
            "lab",
            "production",
            "ungrouped",
            "waf",
            "webservers"
        ]
    },
    "bigip": {
        "hosts": [
            "10.1.1.10",
            "10.1.1.11",
            "10.1.1.5"
        ]
    },
    "datacenter": {
        "hosts": [
            "10.1.1.10",
            "10.1.1.2",
            "10.1.1.3",
            "10.1.1.5",
            "10.1.10.100",
            "10.1.10.20"
        ]
    },
    "lab": {
        "hosts": [
            "10.1.1.3",
            "10.1.1.5",
            "192.168.2.11"
        ]
    },
    "production": {
        "hosts": [
            "1.1.10.20",
            "10.1.1.10",
            "192.168.1.12"
        ]
    },
    "ungrouped": {},
    "waf": {
        "hosts": [
            "mywaf.f5demo.fch"
        ]
    },
    "webservers": {
        "hosts": [
            "10.1.10.100",
            "10.1.10.101",
            "10.1.10.102",
            "10.1.10.103",
            "10.1.10.20"
        ]
    }
}