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 8080lineinfile:dest: /opt/playbook/test/http.confregexp: '^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 8080lineinfile:dest: /opt/playbook/test/http.confregexp: '^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 linelineinfile:dest:  /opt/playbook/test/hostsline: '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 linelineinfile:dest: /opt/playbook/test/testfilestate: presentregexp: '^%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 filePLAY [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 filePLAY [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 filePLAY [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。