Variable name includes a variable

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1

This is something I have been struggling with for a while: a variable whose name includes a variable. For instance, Ansible facts for a server includes the following information on the network interfaces:

“ansible_eth0”: {
“active”: true,
“device”: “eth0”,
“ipv4”: {
“address”: “10.105.12.24”,
“netmask”: “255.255.252.0”,
“network”: “10.105.12.0”
},
“macaddress”: “00:50:56:92:3c:b2”,
“module”: “vmxnet3”,
“mtu”: 1500,
“promisc”: false,
“type”: “ether”
},
“ansible_eth1”: {
“active”: true,
“device”: “eth1”,
“ipv4”: {
“address”: “10.104.24.25”,
“netmask”: “255.255.255.248”,
“network”: “10.104.24.24”
},
“macaddress”: “00:50:56:92:6a:40”,
“module”: “vmxnet3”,
“mtu”: 1500,
“promisc”: false,
“type”: “ether”
},
“ansible_interfaces”: [
“lo”,
“eth1”,
“eth0”
],

In a playbook, I want to walk through the list of interfaces and extract information about each one:

  • debug: msg="interface = {{item}}, address = {{ansible_{{item}}.ipv4.address}}
    with_items: ansible_interfaces
    when: ‘item != “lo”’

This, of course, does not work because of the nested delimiters. So how do I call out something like this?
-Mark

2

mustaches don't stack, to do dynamic vars you need to use hostvars:

      - debug: msg="interface = {{item}}, address = {{
hostvars[inventory_hostname]['ansible_' + item].ipv4.address }}
        with_items: ansible_interfaces
        when: 'item != "lo"'

3

I knew it would be simple if I just asked! That worked perfectly!
Thanks!
-Mark