Ansible dictionnary lookup : I'm trying to generate some nginx config to implement a reverse proxy setup for various docker containers.
The nginx config generation is, tentatively, generated using the below ansible playbooks.

The first block is a dictionnary which contains some metadata for my containers.
The second block is a list of task which is included (see third block) and looped over.
I can see, at the level of my second debug msg, that I'v an issue with my rproxy_fe record since the debug returns nothing.

Any advise on how I should properly write this would be greatly appreciated!   

     net_containers:
      named:
         ipv6_range: "ipv6_prefix:AAAA:AAAA:1::/118"
         ipv6_container: "ipv6_prefix:AAAA:AAAA:1:2"
         ipv6_gw: "ipv6_prefix:AAAA:AAAA:1:1"
         ipv4_range: "192.168.11.64/30"
         ipv4_container: "192.168.11.66"
         ipv4_gw: "192.168.11.65"
         parent_nic: "{{ net_int_dmz_trusted }}"
         rproxy_be : "mx.example.net"
         rproxy_fe : null
         rproxy_url: null
         rproxy_restrict: null
      hass:
         ipv6_range: "ipv6_prefix:AAAA:AAAA:3::/118"
         ipv6_container: "ipv6_prefix:AAAA:AAAA:3:2"
         ipv6_gw: "ipv6_prefix:AAAA:AAAA:3:1"
         ipv4_range: "192.168.11.72/30"
         ipv4_container: "192.168.11.74"
         ipv4_gw: "192.168.11.73"
         parent_nic: "{{ net_int_dmz_trusted }}"
         rproxy_fe : "home.example.net"
         rproxy_be : "hass-container.example.net"
         rproxy_url: "http://hass-container.example.net:8123"
         rproxy_restrict: "true"
This is the list of tasks on which we loop:

    - name: Starting the processing of one new reverse proxied site
      debug: msg="{{ item.key }}"
    
    - name: Checking on the dictionnary lookups
      debug: msg="{{ net_containers[ item.key].rproxy_fe }}"
    
    - name: Install nginx site for letsencrypt requests
      vars:
       rproxy_fe: "{{ net_containers[ item.key].rproxy_fe }}"
      template:
        src: templates/nginx-le.j2
        dest: /etc/nginx/sites-enabled/le-{{ net_containers[ item.key].rproxy_fe }}
      when: net_containers[ item.key].rproxy_fe is defined
    
    - name: Install nginx site for specified site
      vars:
       rproxy_fe: "{{ net_containers[ item.key].rproxy_fe }}"
       rproxy_url: "{{ net_containers[ item.key].rproxy_url }}"
       rproxy_restrict: "{{ net_containers[ item.key].rproxy_restrict }}"
      template:
        src: templates/nginx-http.j2
        dest: /etc/nginx/sites-enabled/http-{{ net_containers[ item.key].rproxy_fe }}
      when: net_containers[ item.key].rproxy_fe is defined
    
    - name: Check if we've generated a cert already
      stat: path=/etc/letsencrypt/live/{{ net_containers[ item.key].rproxy_fe }}/fullchain.pem
      register: cert_stats
    
    - name: Create letsencrypt certificate
      shell: letsencrypt certonly -n --webroot -w /var/www/letsencrypt -m {{ sysadmin_email }} --agree-tos -d {{ net_containers[ item.key ].rproxy_fe }}
      args:
        creates: /etc/letsencrypt/live/{{ net_containers[ item.key].rproxy_fe }}
      when: net_containers[ item.key].rproxy_fe is defined and cert_stats.stat.exists == False
    
    - name: Add letsencrypt cronjob for cert renewal
      cron:
        name: letsencrypt_renewal {{ net_containers[ item.key].rproxy_fe }}
        special_time: weekly
        job: letsencrypt --renew certonly -n --webroot -w /var/www/letsencrypt -m {{ sysadmin_email }} --agree-tos -d {{ net_containers[ item.key].rproxy_fe }}
      when: net_containers[ item.key].rproxy_fe is defined 

This is the import of the task list and the loop:

    - include_tasks: add_domain.yml
      loop: "{{ lookup('dict', net_containers)}}"