Ansible：无法访问主机时中止执行

Question

摘要：一个更好的方法，以中止ansible playbook立即，如果任何主机是无法访问。

如果任何一个主机无法访问，是否有方法中止Ansible playbook。我发现，如果它无法到达主机，它仍将继续运行，并执行剧本中的所有播放/任务。

我所有的剧本都指定max_fail_percent为0，但在本例中ansible不会抱怨，因为所有可访问的主机都可以执行所有的剧本。

目前我有一个简单但黑客的解决方案，但看看是否有一个更好的答案。

- name: Check Ansible connectivity to all hosts
  hosts: host_all
  user: "{{ remote_user }}"
  sudo: "{{ sudo_required }}"
  sudo_user: root
  connection: ssh # or paramiko
  max_fail_percentage: 0
  tasks:
    - name: check connectivity to hosts (Dummy task)
      shell: echo " {{ hostvars[item]['ansible_hostname'] }}"
      with_items: groups['host_all']
      register: cmd_output

    - name: debug ...
      debug: var=cmd_output

如果无法访问主机，您将得到如下错误：

TASK: [c.. ***************************************************** 
fatal: [172.22.191.160] => One or more undefined variables: 'dict object'    has no attribute 'ansible_hostname' 
fatal: [172.22.191.162] => One or more undefined variables: 'dict object' has no attribute 'ansible_hostname'

FATAL: all hosts have already failed -- aborting

Answer 1

或者，这看起来更简单，更有表现力

- hosts: myservers
  become: true

  pre_tasks:
    - name: Check ALL hosts are reacheable before doing the release
      assert:
        that:
          - ansible_play_hosts == groups.myservers
        fail_msg: 1 or more host is UNREACHABLE
        success_msg: ALL hosts are REACHABLE, go on
      run_once: yes

  roles:
    - deploy

https://github.com/ansible/ansible/issues/18782#issuecomment-319409529