How to do it...

1. Create a new Jinja2 file, ospf.j2, in the templates/junos directory, with the following data:

$ cat roles/build_router_config/templates/junos/ospf.j2
 
 protocols {
    ospf {
        area {{global.ospf_area}} {
{%          for intf in p2p_ip[inventory_hostname]|sort(attribute='port') %}
            interface {{ intf.port }} {
                interface-type p2p;
                metric {{intf.cost | default(100)}};
            }
{%          endfor %}
            interface lo0.0 {
                passive;
            }
        }
    }
}

2. In the junos_build_config.yml file inside the tasks folder, add the following task:

$ cat roles/build_router_config/tasks/build_device_config.yml

<-- Output Trimmed for brevity ------>
 
- name: "OSPF Configuration"
  template:
    src: "{{Ansible_network_os}}/ospf.j2"
    dest: "{{config_dir}}/{{ inventory_hostname }}/02_ospf.cfg"