从/etc/resolv.conf文件读取名称服务器(DNS)的ansible playbook

Question

请帮助我编写可解析的剧本，从多个服务器读取/etc/resolv.conf文件中的名称服务器(DNS(，并将这些名称服务器写入一个文件。

我试图将内容放入名为contents的变量中，如下所示：

- name: check resolv.conf exists
stat:
path: /etc/resolv.conf
register: resolv_conf
- name: check nameservers list in resolv.conf
vars:
contents: "{{ lookup('file', '/etc/resolv.conf') }}"
when: resolv_conf.stat.exists == True

然后不确定如何继续。

Answer 1

您可以使用带有过滤器regex_findall的regex来实现这一点，特别是考虑到您可能在那里定义了多个DNS服务器。

注意 这会给你一个列表。

给出剧本：

- hosts: localhost
gather_facts: no
tasks:
- name: check resolv.conf exists
stat:
path: /etc/resolv.conf
register: resolv_conf
- name: check nameservers list in resolv.conf
debug:
msg: "{{ contents }}"
vars:
contents: "{{ lookup('file', '/etc/resolv.conf') | regex_findall('\s*nameserver\s*(.*)') }}"
when: resolv_conf.stat.exists == True

在阿尔卑斯山集装箱上，它给出了回顾：

PLAY [localhost] ***************************************************************
TASK [check resolv.conf exists] ************************************************
ok: [localhost]
TASK [check nameservers list in resolv.conf] ***********************************
ok: [localhost] => {
"msg": [
"192.168.65.1"
]
}
PLAY RECAP *********************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0    skipped=0    rescued=0    ignored=0   

Answer 2

我不确定这是否正是您想要的，但您可以使用lineinfile将内容写入文件中，而不是使用replace模块从文件中替换除名称服务器之外的所有内容。像这样：

- name: Check if resolv exists
stat:
path: /etc/resolv.conf
register: resolv_conf
- set_fact:
content: "{{ lookup('file', '/etc/resolv.conf') }}"
when: resolv_conf.stat.exists

- name: Write them into a file
lineinfile:
line: "{{ content }}"
create: yes
state: present
path: /tmp/resolv_conf_nameservers
- name: Remove everything but nameservers
replace:
path: /tmp/resolv_conf_nameservers
regexp:  "^(?!nameserver).*$"
replace: ""

~
请注意，您应该使用set_fact将内容加载到变量中。

如果您希望将包含名称服务器的文件放在您自己的计算机localhost中，请在最后两个任务中使用delegate_to：

- name: Check if resolv exists
stat:
path: /etc/resolv.conf
register: resolv_conf
- set_fact:
content: "{{ lookup('file', '/etc/resolv.conf') }}"
when: resolv_conf.stat.exists

- name: Write them into a file
lineinfile:
line: "{{ content }}"
create: yes
state: present
path: /tmp/resolv_conf_nameservers
delegate_to: localhost
- name: Remove everything but nameservers
replace:
path: /tmp/resolv_conf_nameservers
regexp:  "^(?!nameserver).*$"
replace: ""
delegate_to: localhost