lineinfile模塊詳解
最后一次修改於2017-05-24 10:34分，個人原創，轉摘請加上原文鏈接http://www.cnblogs.com/kdzm/p/6835182.html
lineinfile模塊類似linux工具中的sed工具，但是網上的文章一般都只有簡單的實例，復雜點的例子都沒有
下面是我根據實際操作總結出來的lineinfile模塊的常見例子，分享給大家參考
目錄
ansible-doc lineinfile官方文檔（英文）--看不懂跳過直接看例子
1、需求：替換匹配的目標值...
2、需求：在匹配值之前增加行...
3、需求：在匹配值之后增加行...
4、需求：匹配到就替換行，未匹配到就新增行...
ansible-doc lineinfile
| > LINEINFILE
This module will search a file for a line, and ensure that it is present or absent. This is primarily useful when you want to change a single line in a file only. See the [replace] module if you want to change multiple, similar lines or chec [blockinfile] if you want to insert/update/remove a block of lines in a file. For other cases, see the [copy] or [template] modules.
Options (= is mandatory):
- backrefs Used with `state=present'. If set, line can contain backreferences (both positional and named) that will get populated if the `regexp' matches. This flag changes the operation of the module slightly; `insertbefore' and `insertafter' will be ignored, and if the `regexp' doesn't match anywhere in the file, the file will be left unchanged. If the `regexp' does match, the last matching line will be replaced by the expanded line parameter. (Choices: yes, no)[Default: no] - backup Create a backup file including the timestamp information so you can get the original file back if you somehow clobbered it incorrectly. (Choices: yes, no)[Default: no] - create Used with `state=present'. If specified, the file will be created if it does not already exist. By default it will fail if the file is missing. (Choices: yes, no)[Default: no] = dest The file to modify. - group name of the group that should own the file/directory, as would be fed to `chown' [Default: None] - insertafter Used with `state=present'. If specified, the line will be inserted after the last match of specified regular expression. A special value is available; `EOF' for inserting the line at the end of the file. If specified regular expression has no matches, EOF will be used instead. May not be used with `backrefs'. (Choices: EOF, *regex*)[Default: EOF] - insertbefore Used with `state=present'. If specified, the line will be inserted before the last match of specified regular expression. A value is available; `BOF' for inserting the line at the beginning of the file. If specified regular expression has no matches, the line will be inserted at the end of the file. May not be used with `backrefs'. (Choices: BOF, *regex*)[Default: (null)] - line Required for `state=present'. The line to insert/replace into the file. If `backrefs' is set, may contain backreferences that will get expanded with the `regexp' capture groups if the regexp matches. [Default: (null)] - mode mode the file or directory should be. For those used to `/usr/bin/chmod' remember that modes are actually octal numbers (like 0644). Leaving off the leading zero will likely have unexpected results. As of version 1.8, the mode may be specified as a symbolic mode (for example, `u+rwx' or `u=rw,g=r,o=r'). [Default: None] - others All arguments accepted by the [file] module also work here. [Default: (null)] - owner name of the user that should own the file/directory, as would be fed to `chown' [Default: None] - regexp The regular expression to look for in every line of the file. For `state=present', the pattern to replace if found; only the last line found will be replaced. For `state=absent', the pattern of the line to remove. Uses Python regular expressions; see http://docs.python.org/2/library/re.html. [Default: (null)] - selevel level part of the SELinux file context. This is the MLS/MCS attribute, sometimes known as the `range'. `_default' feature works as for `seuser'. [Default: s0] - serole role part of SELinux file context, `_default' feature works as for `seuser'. [Default: None] - setype type part of SELinux file context, `_default' feature works as for `seuser'. [Default: None] - seuser user part of SELinux file context. Will default to system policy, if applicable. If set to `_default', it will use the `user' portion of the policy if available [Default: None] - state Whether the line should be there or not. (Choices: present, absent)[Default: present] - unsafe_writes Normally this module uses atomic operations to prevent data corruption or inconsistent reads from the target files, sometimes systems are configured or just broken in ways that prevent this. One example are docker mounted files, they cannot be updated atomically and can only be done in an unsafe manner. This boolean option allows ansible to fall back to unsafe methods of updating files for those cases in which you do not have any other choice. Be aware that this is subject to race conditions and can lead to data corruption. [Default: False] - validate The validation command to run before copying into place. The path to the file to validate is passed in via '%s' which must be present as in the example below. The command is passed securely so shell features like expansion and pipes won't work. |
ansible版本如下
實例
下面用修改防火牆文件來舉例，學習最常見的修改需求
/etc/sysconfig/iptables文件如下：
變量
TOMCAT_PORT=6000
1、需求：替換匹配的目標值
在文件”dest”中，用正則表達式匹配“regexp”值：
若匹配到“regexp”值=1：替換“regexp”值所在行為 “line”；
若匹配到“regexp”值>1：只替換最后一個匹配的有效值；
若匹配到“regexp”值=0：檢查是否存在“backrefs”，並且值等於yes，若是則不做任何操作；否則在文件末尾新增行“line”；
| - name: Lineinfile-iptables lineinfile: dest: /etc/sysconfig/iptables regexp: "ruler:other start" line: "{{item.line}}" backrefs: yes with_items: - { line: '-A INPUT -p tcp -m multiport --dports {{TOMCAT_PORT}} -j ACCEPT'} |
第一次運行
第二次運行
第三次運行由於存在“backrefs: yes”，故結果同第二次一樣。
2、需求：在匹配值之前增加行
在文件”dest”中，故意設定regexp匹配不到，然后匹配“insertbefore”文本：
若匹配到“insertbefore”值=1：匹配“insertbefore”值之前的行，精確匹配行“line”；若匹配行“line”到，不做任何操作；若未匹配到，則在“insertbefore”值之前增加行“line”。
若匹配到“insertbefore”值>1：則只有最后一個“insertbefore”值為有效匹配值，其余同上。
| - name: Lineinfile-iptables lineinfile: dest: /etc/sysconfig/iptables regexp: "ruler:other start" line: "{{item.line}}" insertbefore: "ruler:other end" backrefs: yes with_items: - { line: '-A INPUT -p tcp -m multiport --dports {{TOMCAT_PORT}} -j ACCEPT'} |
3、需求：在匹配值之后增加行
在文件”dest”中，故意設定regexp匹配不到，然后匹配“insertafter”文本：
若匹配到“insertafter”值=1：匹配“insertafter”值之前的行，精確匹配行“line”；若匹配行“line”到，不做任何操作；若未匹配到，則在“insertafter”值之前增加行“line”。
若匹配到“insertafter”值>1：則只有最后一個“insertafter”值為有效匹配值，其余同上。
| - name: Lineinfile-iptables lineinfile: dest: /etc/sysconfig/iptables regexp: "ruler:other start" line: "{{item.line}}" insertafter: " ruler:other start" backrefs: yes with_items: - { line: '-A INPUT -p tcp -m multiport --dports {{TOMCAT_PORT}} -j ACCEPT'} |
注意：如果不加regexp和backrefs項，那么當匹配insertafter的時候，如果匹配到就在前面新增line，如果匹配不到就會在文件末尾新增line（一般這種情況不是我們所希望的）
4、需求：匹配到就替換行，未匹配到就新增行
優先匹配“regexp”，若匹配到則直接替換為“line”，未匹配到則分成下面的情況
① 存在“backrefs: yes” 參數：
A匹配“insertbefore”文本或者“insertafter”文本，若都未匹配到，則不會做任何操作。
B匹配到“insertbefore”文本（匹配多個最后一個有效），會從“insertbefore”文本往前匹配“line”，若匹配不到則新增行“line”，否則不做任何操作。
C匹配到“insertafter”文本（匹配多個最后一個有效），會從“insertafter”文本往后匹配“line”，若匹配不到則新增行“line”，否則不做任何操作。
② 不存在“backrefs: yes” 參數：
A匹配“insertbefore”文本或者“insertafter”文本，若都未匹配到，則在文件末尾新增行“line”。
B匹配到“insertbefore”文本（匹配多個最后一個有效），直接在“insertbefore”文本前面新增行“line”。
C匹配到“insertafter”文本（匹配多個最后一個有效），直接在“insertafter”文本后面新增行“line”。
| - name: Lineinfile-iptables lineinfile: dest: /etc/sysconfig/iptables regexp: "ruler:other start" line: "{{item.line}}" insertbefore: "ruler:other end" # insertafter: "ruler:other start" backrefs: yes with_items: - { line: '-A INPUT -p tcp -m multiport --dports {{TOMCAT_PORT}} -j ACCEPT'} |
第一次運行
第二次運行
當存在backrefs: yes，第三次運行結果與第二次一樣
當不存在backrefs: yes，第三次運行結果
注意：如果不加regexp和backrefs項，那么當匹配insertbefore的時候，如果匹配到就在前面新增line，如果匹配不到就會在文件末尾新增line（一般這種情況不是我們所希望的）