一、简述
这几天在看了ansible官网，收获蛮多。截取一个lineinfile模块作一个总结。如果批量修改配置文件某一行时，在写playbook时lineinfile避免不了的。
根据官网说法：lineinfile - Ensure a particular line is in a file, or replace an existing line using a back-referenced regular expression.大意是说，针对文件特殊行，使用后端引用的正则表达式来替换
二、实践
playbook，我先定义前面common部分。
---
- hosts: "`host`"
remote_user: "`user`"
gather_facts: false
tasks:
由于我已经定义标签tags，执行playbook中某个特定任务时，只需执行到对应TAGNAME便可
ansible-playbook line1.yml --extra-vars "host=gitlab user=root" --tags "TAGNAME" -v
1、正则匹配，更改某个关键参数值
- name: seline modify enforcing
lineinfile:
dest: /etc/selinux/config
regexp: '^SELINUX='
line: 'SELINUX=enforcing'
验证
[root@master test]# cat /etc/selinux/config
# This file controls the state of SELinux on the system.
# SELINUX= can take one of these three values:
# enforcing - SELinux security policy is enforced.
# permissive - SELinux prints warnings instead of enforcing.
# disabled - No SELinux policy is loaded.
SELINUX=enforcing
# SELINUXTYPE= can take one of these two values:
# targeted - Targeted processes are protected,
# mls - Multi Level Security protection.
SELINUXTYPE=targeted
2、在匹配的内容前或后增加一行
2.1 http.conf
[root@master test]# cat http.conf
#Listen 12.34.56.78:80
#Listen 80
#Port
2.2 insertbefore匹配内容在前面添加
- name: httpd.conf modify 8080
lineinfile:
dest: /opt/playbook/test/http.conf
regexp: '^Listen'
insertbefore: '^#Port'
line: 'Listen 8080'
tags:
- http8080
验证
[root@master test]# cat http.conf
#Listen 12.34.56.78:80
#Listen 80
Listen 8080
#Port
2.3 insertafter匹配内容在后面添加
- name: httpd.conf modify 8080
lineinfile:
dest: /opt/playbook/test/http.conf
regexp: '^Listen'
insertafter: '^#Port'
line: 'Listen 8080'
tags:
- http8080
验证
[root@master test]# cat http.conf
#Listen 12.34.56.78:80
#Listen 80
#Port
Listen 8080
3.修改文件内容和权限
3.1 原文件内容及权限
[root@master test]# cat hosts
127.0.0.1 localhost.localdomain localhost ::1 localhost6.localdomain6 localhost6
192.168.1.2 foo.lab.net foo
[root@master test]# ls -l hosts
-rwxrwxr-x 1 root qingyun 111 12月 13 18:07 hosts
3.2 剧本
- name: modify hosts
lineinfile:
dest: /opt/playbook/test/hosts
regexp: '^127\.0\.0\.1'
line: '127.0.0.1 localhosts'
owner: root
group: root
mode: 0644
tags:
- hosts
3.3 执行验证
[root@master test]# cat hosts
127.0.0.1 localhosts
192.168.1.2 foo.lab.net foo
[root@master test]# ls -l hosts
-rw-r--r-- 1 root root 49 12月 13 18:16 hosts
4、删除某一行内容
4.1 原文件
[root@master test]# cat hosts
127.0.0.1 localhosts
192.168.1.2 foo.lab.net foo
4.2 absent剧本
- name: delete 192.168.1.1
lineinfile:
dest: /opt/playbook/test/hosts
state: absent
regexp: '^192\.'
tags:
- delete192
4.3 验证
[root@master test]# cat hosts
127.0.0.1 localhosts
5、文件存在就添加一行
5.1原文件
[root@master test]# cat hosts
127.0.0.1 localhosts
5.2 剧本
- name: add a line
lineinfile:
dest: /opt/playbook/test/hosts
line: '192.168.1.2 foo.lab.net foo'
tags:
- add_a_line
5.3 验证
[root@master test]# cat hosts
127.0.0.1 localhosts
192.168.1.2 foo.lab.net foo
6、如果匹配到，引用line这一行作为替换。如果没有匹配到，则完全引用line这一行作为添加
6.1 原文件
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
6.2 剧本
- name: Fully quoted a line
lineinfile:
dest: /opt/playbook/test/testfile
state: present
regexp: '^%wheel'
line: '%wheel ALL=(ALL) NOPASSWD: ALL'
tags:
- testfile
6.3 验证
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel ALL=(ALL) NOPASSWD: ALL
6.4 原文件
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel 1234 ALL =(all) NOPASSWD
6.5 验证
Using /etc/ansible/ansible.cfg as config file
PLAY [gitlab] ******************************************************************
TASK [Fully quoted a line] *****************************************************
changed: [master] => {"backup": "", "changed": true, "msg": "line replaced"}
PLAY RECAP *********************************************************************
master : ok=1 changed=1 unreachable=0 failed=0
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel ALL=(ALL) NOPASSWD: ALL
7、关于参数backrefs，backup使用。
backrefs为no时，如果没有匹配,则添加一行line。如果匹配了，则把匹配内容替被换为line内容。
backrefs为yes时，如果没有匹配，则文件保持不变。如果匹配了，把匹配内容替被换为line内容。
backup为no时，没有匹配，则添加。如果匹配了，则替换
backup为yes时，没有匹配，添加，如果匹配了，则替换
7.1 需要关心的,backrefs为yes时情景
7.1.1 原文件
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel ALL=(ALL) NOPASSWD: ALL
#?bar
7.1.2 剧本
- name: test backrefs
lineinfile:
# backup: yes
state: present
dest: /opt/playbook/test/testfile
regexp: '^#\?bar'
backrefs: yes
line: 'bar'
tags:
- test_backrefs
7.1.3 验证
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel ALL=(ALL) NOPASSWD: ALL
bar
7.1.3 没有匹配
[root@master test]# cat testfile
# %wheel ALL=(ALL) ALL
%wheel ALL=(ALL) NOPASSWD: ALL
7.1.4 验证
Using /etc/ansible/ansible.cfg as config file
PLAY [gitlab] ******************************************************************
TASK [test backrefs] ***********************************************************
ok: [master] => {"backup": "", "changed": false, "msg": ""}
PLAY RECAP *********************************************************************
master : ok=1 changed=0 unreachable=0 failed=0
文件保持不变
8、使用valiate参数，在保存sudoers文件前，验证语法，如果有错，执行时，会报出来，重新编辑playbook
8.1 剧本
- name: test validate
lineinfile:
dest: /etc/sudoers
state: present
regexp: '^%ADMIN ALL='
line: '%ADMIN ALL=(ALL)'
validate: 'visudo -cf %s'
tags:
- testsudo
8.2 执行验证就说语法不过关
Using /etc/ansible/ansible.cfg as config file
PLAY [gitlab] ******************************************************************
TASK [test validate] ***********************************************************
fatal: [master]: FAILED! => {"changed": false, "failed": true, "msg": "failed to validate: rc:1 error:visudo：>>> /tmp/tmpgQjHYM：syntax error 在行 114 附近<<<\n"}
to retry, use: --limit @/opt/playbook/test/line1.retry
PLAY RECAP *********************************************************************
master : ok=0 changed=0 unreachable=0 failed=1
三、总结
具体模块使用，ansible-doc可以查看详细用法。
