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。