Question

TL / DR：我想在播放中使用“ src_host”和“ dest_host”变量来设置“ -hosts：”对象。但是，我必须为每个游戏的“ -hosts：”部分的“ vars：”下的每个游戏再次设置它们。 src_host =“ {{hostvars ['localhost'] ['src_host']}}”“如何在开始时设置这两个变量而不必重置它们？

我的主机文件看起来像这样

[wordpress]
localhost ansible_user=user ansible_port=22 ansible_ssh_private_key_file=/home/user/.ssh/id_rsa
root_localhost ansible_user=root ansible_port=22 ansible_ssh_private_key_file=/home/user/.ssh/id_rsa

---snip---

server2.net ansible_host="server2.net" ansible_user=user ansible_port=22 ansible_ssh_private_key_file=/home/user/.ssh/id_rsa
root_server2.net ansible_host="server2.net" ansible_user=root ansible_port=22  ansible_ssh_private_key_file=/home/user/.ssh/id_rsa

我的剧本开头看起来像这样：

- hosts: localhost, server2.net, root_server2.net #always include "localhost" in this list because it is needed to store the variables for the src_host and dest_host
  vars:
    src_host: localhost #modify these and the host will be changed for all subsequent plays/tasks
    dest_host: server2.net #modify these and the host will be changed for all subsequent plays/tasks
    src_dump_path: /home/user/cvrt9_dump.sql #set vars for copying file
  roles:  
    - set_facts_for_db_copy

- hosts: "{{ src_host }}" 
  vars: 
    src_host: "{{ hostvars['localhost']['src_host'] }}"
    dest_host: "{{ hostvars['localhost']['dest_host'] }}"
    ---snip---
  roles:
    - dump_db
    - copy_file

等。。

对于“-set_facts_for_db_copy”，我具有“ main.yml”，在其中设置“ src_host”和“ dest_host”变量：

---
# tasks file for set_facts_for_db_copy
- name: create variables that equal src_dump_path and set src_host/dest_host
  set_fact:
    ---snip---
    src_host: "{{ src_host }}"
    dest_host: "{{ dest_host }}"

因此，我需要通过从“ set_fact_for_db_copy”设置的主机变量之一中获取值，为所有后续使用它们的“ -hosts”设置“ src_host”和“ dest_host”。您可能已经注意到，我随机选择了“ localhost”：

src_host: "{{ hostvars['localhost']['src_host'] }}"
dest_host: "{{ hostvars['localhost']['dest_host'] }}"

如果没有那行，我会得到：

user@localhost:/home/maintainer/ansible-play$ ansible-playbook -i hosts_tat-kay playbook.yml 

PLAY [localhost, server2.net, root_server2.net] **************

TASK [setup] *******************************************************************
ok: [server2.net]
ok: [root_server2.net]
ok: [localhost]

TASK [set_facts_for_db_copy : create variables that equal src_dump_path] *******
ok: [localhost]
ok: [server2.net]
ok: [root_server2.net]
ERROR! the field 'hosts' has an invalid value, which appears to include a variable that is undefined. The error was: 'src_host' is undefined

The error appears to have been in '/home/maintainer/ansible-play/playbook.yml': line 14, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:


- hosts: "{{ src_host }}" 
  ^ here

。。。

现在我可以在主机文件中设置以下变量：

[wordpress:vars]
src_host=localhost
dest_host=server2.net

但是接下来，我仍然必须从剧本中随后的“ -hosts：”对象中使用“ {{hostvars ['localhost'] ['src_host']}}”等引用它们。。。因此，我的问题是如何在所有后续的“ -hosts：”对象（如下所示）中删除此冗余代码，同时仍然让我在开始时更改一次“ src_host”和“ dest_host”变量并使这些更改生效其余的戏？谢谢。

    src_host: "{{ hostvars['localhost']['src_host'] }}"
    dest_host: "{{ hostvars['localhost']['dest_host'] }}"

Answer 1

要为此使用清单文件，请按如下所示将需要变量的主机设为父组。

[desireenv:children]
wordpress
otherhost
etc

然后将vars值分配给创建的新父组

[desireenv:vars]
src_host: "{{ hostvars['localhost']['src_host'] }}"
dest_host: "{{ hostvars['localhost']['dest_host'] }}"

Answer 2

我在https://stackoverflow.com/users/4716639/bryan-calvo-benoit的帮助下找到了一个解决方案，就是将其放入主机文件（库存文件）

[wordpress] 
localhost 
server2.net 

[testenv:children] 
wordpress 

[testenv:vars] 
src_host=localhost 
dest_host=server2.net

然后在ansible剧本及其所扮演的角色中，我必须替换

"{{ src_host }}"

与

"{{ hostvars['localhost']['src_host'] }}"

，对于“ {{dest_host}}”同样如此

但是，我可以在我的剧本中删除此冗余代码：

src_host: "{{ hostvars['localhost']['src_host'] }}"
dest_host: "{{ hostvars['localhost']['dest_host'] }}"

如果我不必将src_host和dest_host更改为hostvars ['localhost'] ...会很好，因为使用localhost似乎是任意的，而且如果我想立即运行多个ansible脚本该怎么办？其他具有不同的src_host和dest_host？使用清单文件会将其锁定，因此这不是理想的选择。如果没有其他答案，我将接受此答案，因为它是唯一可行的方法，并且从技术上讲，它可以完成我所提出的问题。

如何在没有冗余代码的情况下在一处为所有后续主机设置变量？

2 个答案: