Looping multiple values for a variable Ansible

Question

I am trying to set multiple values for 2 variables that I am using in the following code:

- name: Create the subnets
  os_subnet:
     cloud: "{{ item.cloud }}"
     state: present
     validate_certs: no
     no_gateway_ip: yes
     enable_dhcp: yes
     name: "{{ item.subnet }}"
     network_name: "{{ item.network }}"
     cidr: "{{ item.cidr }}"
     allocation_pool_start: "{{ item.allocation_pool_start }}"
     allocation_pool_end: "{{ item.allocation_pool_end }}"
     host_routes:
     - destination: "{{ item.destination | default(omit) }}"
       nexthop: "{{ item.nexthop | default(omit) }}"
  with_items:
  - "{{ subnets }}"
  tags: create_subnets

In my environment, some subnets have a different number of host_routes or none. My variable file with one variable for destination+nexthop looks now like:

--- #
subnets:
- { cloud: tenant1, network: nw, subnet: nw_subnet, cidr: 172.10.10.224/27, allocation_pool_start: 172.10.10.228, allocation_pool_end: 172.10.10.254, destination: 10.10.10.0/24, nexthop: 172.10.114.125 }

And this works. But if I am having more than one value for destination+nexthop, how shall I proceed? I have tried yet to duplicate the same line and change just in the end the destination+nexthop, but didn't worked. If I am trying add in the same list one the same row another destination+nexthop, it will take just the last value.

Answer 1

Define host_routes as list in the subnets variable:

subnets: 
- allocation_pool_end: "172.10.10.254"
  allocation_pool_start: "172.10.10.228"
  cidr: 172.10.10.224/27
  cloud: tenant1
  host_routes: 
    - destination: 10.10.10.0/24
      nexthop: "172.10.114.125"
    - destination: YYY.YYY.YYY.YYY/ZZ
      nexthop: XXX.XXX.XXX.XXX
  network: nw
  subnet: nw_subnet
- allocation_pool_end: "172.10.30.254"
  allocation_pool_start: "172.10.30.228"
  cidr: 172.10.30.224/27
  cloud: tenant2
  host_routes: 
    - destination: YYY.YYY.YYY.YYY/ZZ
      nexthop: XXX.XXX.XXX.XXX
  network: nw
  subnet: nw_subnet2

Now you can use it in your task

- name: Ensure subnets are present
  os_subnet:
     cloud: "{{ item.cloud }}"
     state: present
     validate_certs: no
     no_gateway_ip: yes
     enable_dhcp: yes
     name: "{{ item.subnet }}"
     network_name: "{{ item.network }}"
     cidr: "{{ item.cidr }}"
     allocation_pool_start: "{{ item.allocation_pool_start }}"
     allocation_pool_end: "{{ item.allocation_pool_end }}"
     host_routes: "{{ item.host_routes }}"
  with_items:
  - "{{ subnets }}"
  tags: create_subnets