ansible - example of different ways of getting elements from a list of dicts or nested dict structure

play.yml

---
- hosts: localhost
  gather_facts: False
  connection: local
  vars:
    networks:
      - { name: "public", type: public }
      - { name: "private", type: private }
      - { name: "prod-cluster", cidr: "192.172.0.0/24", reverse: "0.172.192.in-addr.arpa", type: cluster }
    alternative:
      public:
        - { name: "public" }
      private:
        - { name: "private" }
      cluster:
        - { name: "prod-cluster", cidr: "192.172.0.0/24", reverse: "0.172.192.in-addr.arpa" }

    selection:
      - public
      - cluster
      - private
  tasks:
    - set_fact:
        networks_in_selection: "{{ networks_in_selection|default([]) + [item] }}"
      when: item.type in selection
      with_items: "{{ networks }}"
      
    # which when Jinja 2.10 is out (http://jinja.pocoo.org/docs/dev/templates/#in) could be rewritten as
    - set_fact:
        networks_in_selection: "{{ networks|selectattr('type', 'in', selection)|list }}"

      
    - set_fact:
        networks_in_selection: "{{ networks_in_selection|default([]) + [item.value] }}"
      when: item.key in selection
      with_dict: "{{ alternative }}"