Ansible: How to modify a list of dicts - ansible

Question

I want to modify dicts in a list within hostvars with a new entry for the IP address I get from the IPAM.
{
"vm_guest_networks": [
{
"device_type": "vmxnet3",
"state": "present",
"subnet": "10.91.1.0/24"
},
{
"device_type": "vmxnet3",
"state": "present",
"subnet": "10.91.0.0/24"
}
]
}
Within a loop I have the subnet to identify the right dict and the IP address I want to add with the ipv4_address key so the result should look like:
{
"vm_guest_networks": [
{
"device_type": "vmxnet3",
"state": "present",
"subnet": "10.91.1.0/24",
"ipv4_address": "10.91.1.216"
},
{
"device_type": "vmxnet3",
"state": "present",
"subnet": "10.91.0.0/24",
"ipv4_address": "10.91.0.21"
}
]
}
The current WIP ansible code is at https://pastebin.com/bFc1Ww2K

Answer 1

Let's assume the list of IPs is available. For example
ip4: [10.91.1.216, 10.91.0.21]
Let's use combine filter and Extended loop variables to create a new list where each dictionary will be updated. For example
- set_fact:
mydata: "{{ mydata|default([]) +
[item|combine({'ipv4_address': ip4[ansible_loop.index0]})] }}"
loop: "{{ vm_guest_networks }}"
loop_control:
extended: yes
- set_fact:
vm_guest_networks: "{{ mydata }}"
- debug:
var: vm_guest_networks
give
"vm_guest_networks": [
{
"device_type": "vmxnet3",
"ipv4_address": "10.91.1.216",
"state": "present",
"subnet": "10.91.1.0/24"
},
{
"device_type": "vmxnet3",
"ipv4_address": "10.91.0.21",
"state": "present",
"subnet": "10.91.0.0/24"
}
]