从剧本中的 ansible 主机文件中读取自定义变量

Question

>我正在尝试读取在 Ansible 主机文件中创建的一些自定义变量，但我无法以某种方式读取它，并且它抛出了异常

主机文件

[webserver]
xx.xx.45.12     uname=abc123 
xx.xx.45.13     uname=pqr456 

剧本 亚姆

- name: sample playbook 
hosts: all
tasks: 
- name: sample echo command   
shell: 
cmd: echo {{hostvars['all'].uname}} 

我找不到任何清楚地谈论如何读取主机变量的文档

当我在上面运行时，我得到下面的错误。

fatal: [xx.xx.45.12]: FAILED! => {"msg": "The task includes an option with an undefined variable. 
The error was: "hostvars['webserver']" is undefinednnThe error appears to be in 
'/mnt/c/Users/ManishBansal/Documents/work/MSS/scripts/run.yaml': line 6, column 7, but maynbe elsewhere 
in the file depending on the exact syntax problem.nnThe offending line appears to be:nn  tasks:n    
- name: This command will get file listn      ^ heren"}

Answer 1

问：">如何读取主机变量？

答：只需引用变量

- command: echo {{ uname }} 

---

例如下面的清单和剧本

shell> cat hosts
[webserver]
test_01     uname=abc123
test_02     uname=pqr456

shell> cat playbook.yml 
- hosts: all
tasks:
- debug:
var: uname

给予(删节(

shell> ansible-playbook -i hosts playbook.yml
ok: [test_01] => 
uname: abc123
ok: [test_02] => 
uname: pqr456

---

使用hostvar引用向其他主机注册的变量。例如

shell> cat playbook.yml 
- hosts: localhost
tasks:
- debug:
var: hostvars[item].uname
loop: "{{ groups.webserver }}"

给予(删节(

shell> ansible-playbook -i hosts playbook.yml
ok: [localhost] => (item=test_01) => 
ansible_loop_var: item
hostvars[item].uname: abc123
item: test_01
ok: [localhost] => (item=test_02) => 
ansible_loop_var: item
hostvars[item].uname: pqr456
item: test_02

---

笔记

• 查看缓存事实

• 引用模块外壳注释

"...最好改用命令模块...">