ansible 2.7.9 使用 host_vars（未定義變量）的問題

Question

Ansible 2.7.9 未使用 host_vars

我用 3 台主機設置了一個非常簡單的設置，主要用於測試目的。 我有主機：

- ansible1 (this is where I store the code)
- ansible2
- ansible3

我的庫存：

[ansible@ansible1 ~]$ cat /etc/ansible/hosts
[common]
ansible1
ansible2
ansible3

我的配置文件看起來像這樣：

[ansible@ansible1 ~]$ cat /etc/ansible/ansible.cfg
[defaults]
roles_path = /etc/ansible/roles
inventory  = /etc/ansible/hosts
[privilege_escalation]
[paramiko_connection]
[ssh_connection]
pipelining = True
control_path = /tmp/ansible-ssh-%%h-%%p-%%r
pipelining = False
[accelerate]
[selinux]
[colors]

我定義了一個名為 common 的主劇本，它調用了 common ：

[ansible@ansible1 ~]$ ls /etc/ansible/roles/
common  common.retry  common.yml
[ansible@ansible1 ~]$ cat /etc/ansible/roles/common.yml
--- # Playbook for webservers
- hosts: common
  roles:
    - common
[ansible@ansible1 ~]$

任務/main.yml ：

[ansible@ansible1 ~]$ cat /etc/ansible/roles/common/tasks/main.yml
- name: test ansible1
  lineinfile:
    dest: /tmp/ansible.txt
    create: yes
    line: "{{ myvar }}"
- name: set ansible2
  lineinfile:
    dest: /tmp/ansible2.txt
    create: yes
    line: "hi"
[ansible@ansible1 ~]$

[ansible@ansible1 ~]$ cat /etc/ansible/roles/common/vars/main.yml
copyright_msg: "Copyrighta 2019"
myvar: "value of myvar from common/vars"

然后我在 /etc/ansible/host_vars 放了一些信息

[ansible@ansible1 ~]$ ls /etc/ansible/hosts_vars/
ansible2.yml
[ansible@ansible1 ~]$ cat /etc/ansible/hosts_vars/ansible2.yml
myvar: "myvar from host_vars"
[ansible@ansible1 ~]$

這適用於劇本：

[ansible@ansible1 ~]$ ansible-playbook /etc/ansible/roles/common.yml --limit ansible2

PLAY [common] ******************************************************************

TASK [Gathering Facts] *********************************************************
ok: [ansible2]

TASK [common : test ansible1] **************************************************
changed: [ansible2]

TASK [common : set ansible2] ***************************************************
changed: [ansible2]

PLAY RECAP *********************************************************************
ansible2                   : ok=3    changed=2    unreachable=0    failed=0

我看到包含 myvar 內容的文件：

[root@ansible2 ~]# cat /tmp/ansible.txt
value of myvar from common/vars
[root@ansible2 ~]#

但是后來我不明白為什么它沒有從 /etc/ansible/hosts_vars/ansible2.yml 中獲取值，事實上，如果我評論 /etc/ansible/roles/common/vars/main.yml 中的行，它表示未定義變量：

[ansible@ansible1 ansible]$ cat /etc/ansible/roles/common/vars/main.yml
copyright_msg: "Copyrighta 2019"
myvar: "value of myvar from common/vars"

Answer 1

Ansible 對來自 vars 的值使用該優先級：

From least to most important
role defaults
inventory file or script group vars
inventory group_vars/all
playbook group_vars/all
inventory group_vars/*
playbook group_vars/*
inventory file or script host vars
inventory host_vars/*
playbook host_vars/*
host facts
play vars
play vars_prompt
play vars_files
role vars (defined in role/vars/main.yml)
block vars (only for tasks in block)
task vars (only for the task)
role (and include_role) params
include params
include_vars
set_facts / registered vars
extra vars (always win precedence)

所以最好忘記使用roles/vars，因為它優先於host_vars，所以我應該使用roles/defaults，它的優先級較低。

Answer 2

正如預期的那樣， main.yml 將在執行劇本時自動獲取。 將此文件視為全局變量。

ansible2.yml 沒有被獲取的原因是因為 ansible 期望你在執行時明確地獲取它。

您可以使用以下代碼（通用）。

---
- name: play
  hosts: "{{ hosts }}"
  tasks:
    - include_vars: "{{ hosts }}.yml"

觸發器 -->

ansible-playbook -i inventory --extra-vars "hosts=ansible2"