ansible - example of command and with_items

play.yml

---
- hosts: foo
  vars:
    gems:
      libxml-ruby: { version: 2.6.0,  state: present, include_dependencies: yes, user_install: no }
      shenzhen: { version: 0.13.1, state: present, include_dependencies: yes, user_install: no }
    gem_executable: /usr/local/rvm/ruby/blah/blah/1.2/gem
  tasks:
    - name: install a bunch of gems - warning, use the right executable and run as the right user!
      gem:
        name: "{{ item.key }}"
        version: "{{ item.version | default(omit) }}"
        state: "{{ item.state | default(omit) }}"
        include_dependencies: "{{ item.include_dependencies | default(omit) }}"
        user_install: "{{ item.user_install | default(omit) }}"
        executable: "{{ gem_executable }}"    
      with_dict: gems

task.yml

- name: Install stupid ruby gems with shell commands
  sudo_user: automationman
  command: bash -lc "gem install {{ item }}"
  with_items:
    - libxml-ruby-2.6.0
    - shenzhen-0.13.1
    - activesupport -v 4.1.8"
    # ...