从其他主机访问变量玩

Question

我的一个玩法是在集群中的组节点上运行，我根据特定条件设置一个变量，例如当节点在集群中成为主节点时将变量设置为“主节点”。

- name: Determine master node in the cluster
  hosts: cluster
  gather_facts: no
  tasks:
   - name: Get the Master node hostname
     shell: <command> 
     register: host_info

   set_fact: 
      master_node: {{ host_info.stdout }}
   when: host_info has "master".            #Sample when condition to understand

我需要从其他主机访问 host_info master_node 变量

- name: Add async standby node
  hosts: new_node
  become: yes
  tasks:
   - debug:
       var: hostvars[item]['master_node']
     loop: "{{ groups['cluster'] }}"

库存：

[cluster]
cluster_01
cluster_02
[new_node]
new_node_01

当我执行此操作时，调试任务显示

TASK [debug] *********************************************************************************************************************************************************************************
ok: [new_node_01] => (item=cluster_01) => {
    "ansible_loop_var": "item",
    "hostvars[item]['primary_node']": "cluster_01",
    "item": "cluster_01"
}
ok: [new_node_01] => (item=cluster_02) => {
    "ansible_loop_var": "item",
    "hostvars[item]['primary_node']": "VARIABLE IS NOT DEFINED!",
    "item": "cluster_02"
}

如何才能只访问定义的循环项？

Answer 1

我就这样用过，效果很好

- set_fact:
    primary_host: "{{ hostvars[item]['master_node'] }}"
  loop: "{{ groups['cluster'] }}"
  when: hostvars[item]['master_node'] is defined

执行日志

ok: [new_node_01] => (item= cluster_01) => {
    "ansible_facts": {
        "primary_host": "cluster_01"
    },
    "ansible_loop_var": "item",
    "changed": false,
    "item": "cluster_01"
}
skipping: [new_node_01] => (item= cluster_02)  => {
    "ansible_loop_var": "item",
    "changed": false,
    "item": "cluster_02",
    "skip_reason": "Conditional result was False"
}