我如何在没有指定主机的情况下运行Ansible playbook？

Question

我正在编写一个剧本，它旋转X个EC2 AWS实例，然后在它们上安装一些软件（apt包和pip模块）。当我运行playbook时，它会在我的本地系统上执行shell命令，因为Ansible不会运行，除非我指定一个主机并放置localhost。

在playbook中，我尝试在顶层指定“hosts：all”，但这只会让playbook运行一秒钟而不做任何事情。

- name: Spin up spot instances
  hosts: localhost
  connection: local
  vars_files: ansible-vars.yml
  tasks:
    - name: create {{ spot_count }} spot instances with spot_price of ${{ spot_price }}      
      local_action:
        module: ec2
        region: us-east-2
        spot_price:  '{{ spot_price }}'
        spot_wait_timeout: 180
        keypair: My-keypair
        instance_type: t3a.nano
        image: ami-0f65671a86f061fcd
        group: Allow from Home
        instance_initiated_shutdown_behavior: terminate
        wait: yes
        count:  '{{ spot_count }}'
      register: ec2

    - name: Wait for the instances to boot by checking the ssh port
      wait_for: host={{item.public_ip}} port=22 delay=15 timeout=300 state=started
      with_items: "{{ ec2.instances }}"

    - name: test whoami
      args:
        executable: /bin/bash
      shell: whoami
      with_items: "{{ ec2.instances }}"

    - name: Update apt
      args:
        executable: /bin/bash
      shell: apt update
      become: yes
      with_items: "{{ ec2.instances }}"

    - name: Install Python and Pip
      args:
        executable: /bin/bash
      shell: apt install python3 python3-pip -y        
      become: yes
      with_items: "{{ ec2.instances }}"

    - name: Install Python modules
      args:
        executable: /bin/bash
      shell: pip3 install bs4 requests
      with_items: "{{ ec2.instances }}"

ansible_ssh_private_key_file: ~/.ssh/my-keypair.pem
spot_count: 1
spot_price: '0.002'
remote_user: ubuntu

EC2实例创建得很好，“wait for ssh”任务可以工作，但是shell任务在本地系统上运行，而不是在远程主机上运行。

既然我们是在动态创建EC2实例，我如何告诉Ansible在不使用主机文件的情况下连接到EC2实例呢？

Answer 1

如果有用的话你能试试这个吗。

- name: test whoami
      args:
        executable: /bin/bash
      shell: whoami
      delegate_to: "{{ item }}"
      with_items: "{{ ec2.instances }}"