第十二周练习题

2021/11/11 23:12:13

本文主要是介绍第十二周练习题,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

1、主从复制及主主复制的实现

#实现主从复制配置,官网参考
https://dev.mysql.com/doc/refman/8.0/en/replication-configuration.html
https://dev.mysql.com/doc/refman/5.7/en/replication-configuration.html
https://dev.mysql.com/doc/refman/5.5/en/replication-configuration.html
https://mariadb.com/kb/en/library/setting-up-replication/

#一、两台centos8安装mariadb10.3.28 实现主从复制

#主节点配置:
[root@Centos8 ~]##hostnamectl set-hostname master
[root@master ~]#yum install -y mariadb-server
[root@master ~]#vim /etc/my.cnf.d/mariadb-server.cnf

[mysqld]
log_bin
server-id=11

#设置开机自启并启动服务
[root@master ~]#systemctl --now enable mariadb
Created symlink /etc/systemd/system/mysql.service → /usr/lib/systemd/system/mariadb.service.
Created symlink /etc/systemd/system/mysqld.service → /usr/lib/systemd/system/mariadb.service.
Created symlink /etc/systemd/system/multi-user.target.wants/mariadb.service → /usr/lib/systemd/system/mariadb.service.



#登录数据库
[root@master ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 9
Server version: 10.3.28-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-bin.000002 |      343 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.000 sec)
#创建复制账号
MariaDB [(none)]> grant replication slave on *.* to 'repluser'@'10.0.0.%' identified by 'replpass';
Query OK, 0 rows affected (0.000 sec)
#刷新权限
MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.000 sec)
#查看二进制文件名称及位置,后面从节点会用到
MariaDB [(none)]> show master status;
+-------------------+----------+--------------+------------------+
| File              | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+-------------------+----------+--------------+------------------+
| master-bin.000003 |      343 |              |                  |
+-------------------+----------+--------------+------------------+
1 row in set (0.000 sec)
#退出数据库
MariaDB [(none)]> exit
Bye


#从节点配置:
[root@Centos8 ~]#hostnamectl set-hostname slave1
[root@slave1 ~]#yum install -y mariadb-server
[root@slave1 ~]#vim /etc/my.cnf.d/mariadb-server.cnf

[mysqld]
server_id=22
log-bin
read_only=ON
relay_log=relay-log
relay_log_index=relay-log.index

[root@slave1 ~]#systemctl --now enable mariadb
Created symlink /etc/systemd/system/mysql.service → /usr/lib/systemd/system/mariadb.service.
Created symlink /etc/systemd/system/mysqld.service → /usr/lib/systemd/system/mariadb.service.
Created symlink /etc/systemd/system/multi-user.target.wants/mariadb.service → /usr/lib/systemd/system/mariadb.service.

#使用有复制权限的用户账号连接至主服务器,并启动复制线程
[root@slave1 ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 9
Server version: 10.3.28-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> change master to master_host='10.0.0.150',master_user='repluser',master_password='replpass',master_log_file='master-bin.000003',master_log_pos=343;
Query OK, 0 rows affected (0.002 sec)

#开始从节点复制
MariaDB [(none)]> start slave ;
Query OK, 0 rows affected (0.001 sec)
#查看从节点复制状态
MariaDB [(none)]> show slave status \G;
*************************** 1. row ***************************
                Slave_IO_State: Waiting for master to send event
                   Master_Host: 10.0.0.150
                   Master_User: repluser
                   Master_Port: 3306
                 Connect_Retry: 60
               Master_Log_File: master-bin.000003
           Read_Master_Log_Pos: 343
                Relay_Log_File: relay-log.000002
                 Relay_Log_Pos: 556
         Relay_Master_Log_File: master-bin.000003
              Slave_IO_Running: Yes
             Slave_SQL_Running: Yes    #出现这两个yes表示连接成功,配置成功




#说明,从节点配置错误,清除信息后检查从节点配置重新配置change master to
MariaDB [(none)]> stop slave;
Query OK, 0 rows affected (0.002 sec)

MariaDB [(none)]> reset slave all;
Query OK, 0 rows affected (0.000 sec)

#验证主从复制
#主节点创建数据库
第一次查看数据库
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.000 sec)

主节点创建test111数据库
MariaDB [(none)]> create database test111;
Query OK, 1 row affected (0.000 sec)

#从节点查看是否同步
第一次查看数据库
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.001 sec)

在主节点创建test111数据库后,在从节点查看数据库,发现已经同步过来
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| test111            |
+--------------------+
4 rows in set (0.000 sec)




#二、两台centos8安装mariadb10.3.28 实现主主复制
主主复制:两个节点,都可以更新数据,并且互为主从
容易产生的问题:数据不一致;因此慎用
考虑要点:自动增长id
配置一个节点使用奇数id
auto_increment_offset=1   #开始点
auto_increment_increment=2 #增长幅度
另一个节点使用偶数id
auto_increment_offset=2
auto_increment_increment=2
主主复制的配置步骤简述:
 (1) 各节点使用一个惟一server_id
 (2) 都启动binary log和relay log
 (3) 创建拥有复制权限的用户账号
 (4) 定义自动增长id字段的数值范围各为奇偶
 (5) 均把对方指定为主节点,并启动复制线程

主主复制的具体实现步骤:
#第一台mster节点
[root@master1 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
log_bin
server-id=11
auto_increment_offset=1
auto_increment_increment=2

[root@master1 ~]#systemctl restart mariadb
[root@master1 ~]#mysql
MariaDB [(none)]> show master status;
+--------------------+----------+--------------+------------------+
| File               | Position | Binlog_Do_DB | Binlog_Ignore_DB |
+--------------------+----------+--------------+------------------+
| master1-bin.000001 |      330 |              |                  |
+--------------------+----------+--------------+------------------+
1 row in set (0.000 sec)

MariaDB [(none)]> show master logs;
+--------------------+-----------+
| Log_name           | File_size |
+--------------------+-----------+
| master1-bin.000001 |       330 |
+--------------------+-----------+
1 row in set (0.000 sec)
#说明,如果是先查看在创建复制账号,则下面的创建账号信息不会同步到从节点。如果先创建的复制账号,再查看的二进制文件位置,则会把账号创建也复制过去。
MariaDB [(none)]> grant replication slave on *.* to 'repluser'@'*' identified by 'replpass';
MariaDB [(none)]>flush privileges;



#第二台master节点
[root@master2 ~]#vim  /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
server_id=22
log-bin
auto_increment_offset=2
auto_increment_increment=2
[root@master2 ~]#systemctl restart mariadb
[root@master2 ~]#mysql
MariaDB [(none)]> change master to master_host='10.0.0.150',master_user='repluser',master_password='replpass',master_log_file='master1-bin.000001',master_log_pos=330;
Query OK, 0 rows affected (0.011 sec)

MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> show master logs;
+--------------------+-----------+
| Log_name           | File_size |
+--------------------+-----------+
| master2-bin.000001 |      913  |
+--------------------+-----------+
1 row in set (0.000 sec)

#因上面没有先创建复制用户再查看二进制文件位置,所以创建账号这步没有同步过来,因此这台也要创建复制账号。
MariaDB [(none)]>grant replication slave on *.* to 'repluser'@'*' identified by 'replpass';
MariaDB [(none)]>flush privileges;

#回到第一台master节点
因为第一台的复制账号信息已经同步到第二台机器,因此有复制账号了,直接配置change master to 

MariaDB [(none)]> change master to master_host='10.0.0.160',master_user='repluser',master_password='replpass',master_log_file='master2-bin.000001',master_log_pos=913;
Query OK, 0 rows affected (0.014 sec)
#启动复制线程
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.001 sec)

#验证
#第一台
MariaDB [(none)]> create database d111;
Query OK, 1 row affected (0.000 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| d111               |
| d222               |
| information_schema |
| mysql              |
| performance_schema |
| t1                 |
| test111            |
+--------------------+
7 rows in set (0.000 sec)

#第二台
MariaDB [(none)]> create database d222;
Query OK, 1 row affected (0.000 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| d111               |
| d222               |
| information_schema |
| mysql              |
| performance_schema |
| t1                 |
| test111            |
+--------------------+
7 rows in set (0.000 sec)

2、xtrabackup实现全量+增量+binlog恢复库

#一、利用xtrabackup实现完全备份及还原 

1.下载并安装xtrabackup包 
[root@centos8 ~]#wget https://downloads.percona.com/downloads/Percona-XtraBackup-2.4/Percona-XtraBackup-2.4.23/binary/redhat/7/x86_64/percona-xtrabackup-24-2.4.23-1.el7.x86_64.rpm
[root@localhost ~]# yum install -y percona-xtrabackup-24-2.4.23-1.el7.x86_64.rpm

2.安装mariadb数据库并启动服务
[root@localhost ~]# yum install -y mariadb-server
[root@localhost ~]# systemctl enable mariadb --now
[root@localhost ~]# mysql_secure_installation(初始化设置,设置root密码为123456,移除匿名用户等)

3.在原主机做完全备份到/backup目录
[root@localhost ~]# mkdir /backup
[root@localhost ~]# xtrabackup -uroot -p123456 --backup --target-dir=/backup/base
[root@localhost ~]# ls /backup/base/
backup-my.cnf  mysql               xtrabackup_checkpoints  xtrabackup_logfile
ibdata1        performance_schema  xtrabackup_info

4.目标主机无需创建/backup目录,直接复制目录本身
[root@centos7 ~]#scp -r /backup/ 目标主机:/backup1

5.删除数据库数据模拟目标主机
[root@localhost ~]# systemctl stop mariadb
[root@localhost ~]# rm -rf /var/lib/mysql/*

6.还原数据
1)预准备:确保数据一致,提交完成的事务,回滚未完成的事务
[root@localhost ~]# xtrabackup --prepare --target-dir=/backup/base

2)复制到数据库目录
注意:数据库目录必须为空,MySQL服务不能启动
[root@localhost ~]# xtrabackup --copy-back --target-dir=/backup/base
[root@localhost ~]# ll /var/lib/mysql/
total 40976
-rw-r----- 1 root root 18874368 Nov  9 16:47 ibdata1
-rw-r----- 1 root root  5242880 Nov  9 16:47 ib_logfile0
-rw-r----- 1 root root  5242880 Nov  9 16:47 ib_logfile1
-rw-r----- 1 root root 12582912 Nov  9 16:47 ibtmp1
drwxr-x--- 2 root root     4096 Nov  9 16:47 mysql
drwxr-x--- 2 root root     4096 Nov  9 16:47 performance_schema
-rw-r----- 1 root root      440 Nov  9 16:47 xtrabackup_info
-rw-r----- 1 root root        1 Nov  9 16:47 xtrabackup_master_key_id

3)还原属性
[root@centos7 ~]#chown -R mysql:mysql /var/lib/mysql
[root@localhost ~]# ll /var/lib/mysql/
total 40976
-rw-r----- 1 mysql mysql 18874368 Nov  9 16:47 ibdata1
-rw-r----- 1 mysql mysql  5242880 Nov  9 16:47 ib_logfile0
-rw-r----- 1 mysql mysql  5242880 Nov  9 16:47 ib_logfile1
-rw-r----- 1 mysql mysql 12582912 Nov  9 16:47 ibtmp1
drwxr-x--- 2 mysql mysql     4096 Nov  9 16:47 mysql
drwxr-x--- 2 mysql mysql     4096 Nov  9 16:47 performance_schema
-rw-r----- 1 mysql mysql      440 Nov  9 16:47 xtrabackup_info
-rw-r----- 1 mysql mysql        1 Nov  9 16:47 xtrabackup_master_key_id

4)启动服务
[root@centos7 ~]#systemctl start  mariadb

7.验证数据恢复成功
[root@localhost ~]# mysql -uroot -p123456
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 2
Server version: 5.5.68-MariaDB MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
+--------------------+
3 rows in set (0.00 sec)


#二、完全,增量+binlog还原
#完全备份
[root@centos7 ~]#yum install -y percona-xtrabackup-24-2.4.23-1.el7.x86_64.rpm
[root@centos7 ~]#mkdir /backup/
[root@centos7 ~]#xtrabackup -uroot -p123456 --backup --target-dir=/backup/base
#新增数据
MariaDB [(none)]> create database testdb
    -> ;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| testdb             |
+--------------------+
4 rows in set (0.00 sec)

#第一次增量备份
[root@localhost ~]# xtrabackup -uroot -p123456 --backup --target-dir=/backup/inc1 --incremental-basedir=/backup/base

#第二次新增数据
MariaDB [(none)]> create database testdb2
    -> ;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| testdb             |
| testdb2            |
+--------------------+
5 rows in set (0.00 sec)

#第二次增量备份
[root@localhost ~]# xtrabackup -uroot -p123456 --backup --target-dir=/backup/inc2 --incremental-basedir=/backup/inc1

#二次增量备份后查看二进制位置,防止二次备份后再次有少量数据写入,这时就需要二进制日志来恢复数据
MariaDB [(none)]> show master logs;
+--------------------+-----------+
| Log_name           | File_size |
+--------------------+-----------+
| mariadb-bin.000001 |       1645 |
+--------------------+-----------+
1 row in set (0.00 sec)

#第二次增备后新增数据:
MariaDB [(none)]> create database testdb3
    -> ;
Query OK, 1 row affected (0.00 sec)

MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| mysql              |
| performance_schema |
| testdb             |
| testdb2            |
| testdb3            |
+--------------------+
6 rows in set (0.00 sec)
#拷贝binlog日志留作恢复
[root@localhost mysql]# cp -p /var/lib/mysql/mariadb-bin.000001  /backup/


#拷贝到还原主机
 [root@localhost ~]#scp -r /backup/ 目标主机:/backup/
#备份过程生成三个备份目录
/backup/{base,inc1,inc2} 

#数据还原过程:(数据库未启动状态)
1)预准备完成备份,此选项--apply-log-only 阻止回滚未完成的事务
[root@localhost ~]#xtrabackup --prepare --apply-log-only --target-dir=/backup/base
2)合并第1次增量备份到完全备份
[root@localhost ~]#xtrabackup --prepare --apply-log-only --target-dir=/backup/base --incremental-dir=/backup/inc1
3)合并第2次增量备份到完全备份:最后一次还原不需要加选项--apply-log-only
[root@localhost ~]#xtrabackup --prepare --target-dir=/backup/base --incrementaldir=/backup/inc2
4)复制到数据库目录,注意数据库目录必须为空,MySQL服务不能启动
[root@localhost ~]#xtrabackup --copy-back --target-dir=/backup/base
5)还原属性: 
[root@localhost ~]# chown -R  mysql:mysql /var/lib/mysql/
 6)启动服务:
[root@localhost ~]# systemctl start mariadb

#截至第二次增备的数据都已经恢复,但是第二次增备后原数据库还有可能会写入数据,最后的少量数据使用binlog恢复
[root@localhost mysql]# cat /backup/inc2/xtrabackup_binlog_info
mariadb-bin.000001      1645
#查看二进制文件,从1645开始,并导入到sql文件
[root@localhost ~]# mysqlbinlog  /backup/mariadb-bin.000001 --start-position=1645 >/backup/binlog.sql

#临时关闭binlog记录功能,导入sql文件,再开机binlog功能
MariaDB [(none)]> set sql_log_bin=0;
MariaDB [(none)]> source /backup/binlog.sql
MariaDB [(none)]> set sql_log_bin=1;
#验证
MariaDB [(none)]> show databases;
+--------------------+
| Database           |
+--------------------+
| information_schema |
| testdb             |
| testdb2            |
| testdb3            |
| performance_schema |
+--------------------+
5 rows in set (0.00 sec)

3、MyCAT实现MySQL读写分离

#三台服务器
centos7  mycat-server  10.0.0.152  内存2G以上
centos8  mysql-master  10.0.0.150  mariadb 10.3
centos8  mysql-master  10.0.0.160  mariadb 10.3

#关闭防火墙
systemctl stop firewalld
setenforce 0
时间同步

#1)创建数据库主从
[root@centos8 ~]#yum install -y mariadb-server
#master和slave修改配置文件
#master:
[root@centos8 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]#
server-id=1
log-bin

#slave:
[root@centos8 ~]#vim /etc/my.cnf.d/mariadb-server.cnf
[mysqld]
server-id=2

#修改配置文件后重启服务使生效
[root@centos8 ~]#systemctl start mariadb

#master:创建复制账号
[root@centos8 ~]#mysql
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 9
Server version: 10.3.28-MariaDB-log MariaDB Server

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> grant replication slave on *.* to 'repluser'@'%' identified by 'replpass';
Query OK, 0 rows affected (0.000 sec)

MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.000 sec)
MariaDB [(none)]> show master logs;
+--------------------+-----------+
| Log_name           | File_size |
+--------------------+-----------+
| mariadb-bin.000001 |       645 |
+--------------------+-----------+
1 row in set (0.000 sec)


#slave:连接主数据库
MariaDB [(none)]> change master to master_host='10.0.0.150',master_user='repluser',master_password='replpass',master_log_file='mariadb-bin.000001',master_log_pos=645;
Query OK, 0 rows affected (0.002 sec)
MariaDB [(none)]> start slave;
Query OK, 0 rows affected (0.001 sec)

MariaDB [(none)]> show slave status \G;
			......
             Slave_IO_Running: Yes
             Slave_SQL_Running: Yes
			......省略
			
#2)在mysql代理服务器10.0.0.152上安装mycat并启动
#安装jdk
[root@localhost ~]# yum install -y java
[root@localhost ~]# java -version
openjdk version "1.8.0_312"
OpenJDK Runtime Environment (build 1.8.0_312-b07)
OpenJDK 64-Bit Server VM (build 25.312-b07, mixed mode)

#下载并安装mycat
[root@localhost ~]# wget http://dl.mycat.org.cn/1.6.7.6/20210303094759/Mycat-server-1.6.7.6-release-20210303094759-linux.tar.gz

或者#wget http://dl.mycat.org.cn/1.6.7.4/Mycat-server-1.6.7.4-release/Mycat-server-1.6.7.4-release-20200105164103-linux.tar.gz

[root@localhost ~]# mkdir /apps
[root@localhost ~]# tar xvf Mycat-server-1.6.7.6-release-20210303094759-linux.tar.gz  -C /apps

#配置环境变量
[root@localhost ~]# echo 'PATH=$PATH:/apps/mycat/bin'>/etc/profile.d/mycat.sh
[root@localhost ~]# source /etc/profile.d/mycat.sh

#启动mycat
[root@localhost ~]# ss -ntl
State      Recv-Q Send-Q Local Address:Port               Peer Address:Port
LISTEN     0      128               *:111                           *:*
LISTEN     0      128               *:22                            *:*
LISTEN     0      100       127.0.0.1:25                            *:*
LISTEN     0      128            [::]:111                        [::]:*
LISTEN     0      128            [::]:22                         [::]:*
LISTEN     0      100           [::1]:25                         [::]:*
[root@localhost ~]# mycat start
Starting Mycat-server...
[root@localhost ~]# ss -ntl
State      Recv-Q Send-Q Local Address:Port               Peer Address:Port
LISTEN     0      1         127.0.0.1:32000                         *:*
LISTEN     0      128               *:111                           *:*
LISTEN     0      128               *:22                            *:*
LISTEN     0      100       127.0.0.1:25                            *:*
LISTEN     0      50             [::]:1984                       [::]:*
LISTEN     0      128            [::]:8066                       [::]:*
LISTEN     0      50             [::]:43650                      [::]:*
LISTEN     0      128            [::]:9066                       [::]:*
LISTEN     0      128            [::]:111                        [::]:*
LISTEN     0      128            [::]:22                         [::]:*
LISTEN     0      100           [::1]:25                         [::]:*
LISTEN     0      50             [::]:34334                      [::]:*

#可以看到启动了多个端口,其中8066用于连接myscat
[root@localhost ~]# tail /apps/mycat/logs/wrapper.log
可以看到启动成功了

#用默认密码123456来连接mycat
[root@localhost ~]# mysql -uroot -p123456 -h10.0.0.152 -P8066
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.29-mycat-1.6.7.6-release-20210303094759 MyCat Server (OpenCloudDB)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [(none)]> show databases;
+----------+
| DATABASE |
+----------+
| TESTDB   |
+----------+
1 row in set (0.00 sec)

#3)在mycat服务器上修改server.xml文件配置mycat的连接信息
[root@localhost ~]# vim /apps/mycat/conf/server.xml
#修改下面行的8066改为3306复制到到独立非注释行
<property name="serverPort">3306</property>
<property name="handlelDistributedTransactions">0</property> #将上面行放在此行前面
或者删除注释,并修改下面的8066为3306
<property name="serverPort">3306</property>
<property name="managerPort">9066</property>
<property name="idleTimeout">300000</property>
<property name="authTimeout">15000</property>
<property name="bindIp">0.0.0.0</property>
<property name="dataNodeIdleCheckPeriod">300000</property> #5 * 60 * 1000L; //连
接空闲检查 删除#后面此部分
<property name="frontWriteQueueSize">4096</property> <property 
name="processors">32</property> #--> 删除#后面此部分
 .....
<user name="root">                                       #连接Mycat的用户名
   <property name="password">magedu</property>          #连接Mycat的密码
   <property name="schemas">TESTDB</property>           #数据库名要和schema.xml相
对应


#这里使用的是root,密码为magedu,逻辑数据库为TESTDB,这些信息都可以自己随意定义,读写权限都有,没有针对表做任何特殊的权限。重点关注上面这段配置,其他默认即可。

#4)修改schema.xml实现读写分离策略
[root@localhost ~]# vim /apps/mycat/conf/schema.xml
#最终文件内容
[root@mycat ~]#cat /apps/mycat/conf/schema.xml
<?xml version="1.0"?>
<!DOCTYPE mycat:schema SYSTEM "schema.dtd">
<mycat:schema xmlns:mycat="http://io.mycat/">
 <schema name="TESTDB" checkSQLschema="false" sqlMaxLimit="100"
dataNode="dn1">
 </schema>
 <dataNode name="dn1" dataHost="localhost1" database="hellodb" />
 <dataHost name="localhost1" maxCon="1000" minCon="10" balance="1"
  writeType="0" dbType="mysql" dbDriver="native" switchType="1"
slaveThreshold="100">
 <heartbeat>select user()</heartbeat>
 <writeHost host="host1" url="10.0.0.18:3306" user="mycat"
   password="123456">
         <readHost host="host2" url="10.0.0.28:3306" user="mycat"
password="123456" />
 </writeHost>
   </dataHost>
</mycat:schema>

#重新启动mycat
root@localhost ~]# mycat restart
Stopping Mycat-server...
Mycat-server was not running.
Starting Mycat-server...
[root@localhost ~]# tail /apps/mycat/logs/wrapper.log
INFO   | jvm 1    | 2021/11/09 22:49:04 |       at io.mycat.config.util.ConfigUtil.getDocument(ConfigUtil.java:115)
INFO   | jvm 1    | 2021/11/09 22:49:04 |       at io.mycat.config.loader.xml.XMLSchemaLoader.load(XMLSchemaLoader.java:111)
INFO   | jvm 1    | 2021/11/09 22:49:04 |       ... 13 more
STATUS | wrapper  | 2021/11/09 22:49:06 | <-- Wrapper Stopped
STATUS | wrapper  | 2021/11/09 22:53:37 | --> Wrapper Started as Daemon
STATUS | wrapper  | 2021/11/09 22:53:38 | Launching a JVM...
INFO   | jvm 1    | 2021/11/09 22:53:38 | Wrapper (Version 3.2.3) http://wrapper.tanukisoftware.org
INFO   | jvm 1    | 2021/11/09 22:53:38 |   Copyright 1999-2006 Tanuki Software, Inc.  All Rights Reserved.
INFO   | jvm 1    | 2021/11/09 22:53:38 |
INFO   | jvm 1    | 2021/11/09 22:53:41 | MyCAT Server startup successfully. see logs in logs/mycat.log


#5)在10.0.0.150的后端数据库创建用户并授权

MariaDB [(none)]> grant all privileges on *.* to 'mycat'@'10.0.0.%' identified by '123456';
Query OK, 0 rows affected (0.000 sec)

MariaDB [(none)]> flush privileges;
Query OK, 0 rows affected (0.000 sec)

MariaDB [(none)]> exit
Bye
[root@centos8 ~]#mysql -h10.0.0.150 -umycat -p123456

#6)连接并测试,可以看到进入逻辑数据库TESTDB,查到我后端hellodb数据库里面的内容,成功
[root@localhost ~]# mysql -uroot -pmagedu -h10.0.0.152 TESTDB
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A

Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MySQL connection id is 1
Server version: 5.6.29-mycat-1.6.7.6-release-20210303094759 MyCat Server (OpenCloudDB)

Copyright (c) 2000, 2018, Oracle, MariaDB Corporation Ab and others.

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MySQL [TESTDB]> show databases;
+----------+
| DATABASE |
+----------+
| TESTDB   |
+----------+
1 row in set (0.00 sec)

MySQL [TESTDB]> show tables;
+-------------------+
| Tables_in_hellodb |
+-------------------+
| tbl1              |
+-------------------+
1 row in set (0.00 sec)

MySQL [TESTDB]> select * from tbl1;
+------+----------+
| id   | name     |
+------+----------+
|    1 | tanliang |
+------+----------+
1 row in set (0.00 sec)
MySQL [TESTDB]> select @@hostname;
+--------------------+
| @@hostname         |
+--------------------+
| centos8.magedu.org |
+--------------------+
1 row in set (0.00 sec)

MySQL [TESTDB]> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           2 |
+-------------+
1 row in set (0.00 sec)

#7)通过日志确认实现读写分离
show variables like 'general_log';  #查看日志是否开启
set global general_log=on;    #开启日志功能
show variables like 'general_log_file'; #查看日志文件保存位置
set global general_log_file='tmp/general.log'; #设置日志文件保存位置

#在主和从服务器分别开启通用日志,查看读写分离
#操作:
MySQL [TESTDB]> show tables;
+-------------------+
| Tables_in_hellodb |
+-------------------+
| tbl1              |
+-------------------+
1 row in set (0.00 sec)

MySQL [TESTDB]> select * from tbl1;
+------+----------+
| id   | name     |
+------+----------+
|    1 | tanliang |
+------+----------+
1 row in set (0.01 sec)

MySQL [TESTDB]> insert tbl1 value(2,'liang');
Query OK, 1 row affected (0.01 sec)

主:
[root@master mysql]#tail -f centos8.log
211109 23:03:41     20 Query    select user()
                    24 Connect  mycat@10.0.0.152 as anonymous on hellodb
211109 23:03:51     17 Query    select user()
211109 23:04:01     16 Query    SET names utf8;insert tbl1 value(2,'liang')
                    23 Query    select user()
^C
从:
211109 23:02:04     16 Query    SET names utf8;show tables
211109 23:02:11     15 Query    select user()
211109 23:02:21     13 Query    select user()
211109 23:02:31     12 Query    select user()
211109 23:02:41     14 Query    select user()
211109 23:02:51     11 Query    select user()
211109 23:03:01     16 Query    select user()
211109 23:03:11     15 Query    select user()
211109 23:03:12     13 Query    select * from tbl1
211109 23:03:21     12 Query    select user()
211109 23:03:31     14 Query    select user()
211109 23:03:41     11 Query    select user()
                    18 Connect  mycat@10.0.0.152 as anonymous on hellodb
211109 23:03:51     16 Query    select user()
211109 23:04:01     10 Query    BEGIN
                    10 Query    insert tbl1 value(2,'liang')
                    10 Query    COMMIT /* implicit, from Xid_log_event */
                    15 Query    select user()
#MyCAT对后端服务器的健康性检查方法select user()
#停止从节点,MyCAT自动调度读请求至主节点,#停止主节点,MyCAT不会自动调度写请求至从节点
slave上停止mariadb
[root@slave1 mysql]#systemctl stop mariadb

[root@localhost ~]# mysql -uroot -pmagedu -h10.0.0.152 TESTDB
MySQL [TESTDB]> select @@server_id;
+-------------+
| @@server_id |
+-------------+
|           1 |
+-------------+
1 row in set (0.00 sec)

4、ansible常用模块介绍

s常用模块帮助文档参考:
https://docs.ansible.com/ansible/2.9/modules/modules_by_category.html
https://docs.ansible.com/ansible/2.9/modules/list_of_all_modules.html

1)Command模块
功能:在远程主机执行命令,此为默认模块,可忽略-m选项
说明:此命令不支持 $VARNAME < > | ; & 等,可用shell模块实现。
说明:此模块不具有幂等性(幂等性:多次执行不影响结果)
#chdir切换工作目录
[root@master tasks]#ansible webservers -m command -a "chdir=/etc cat centos-release"
10.0.0.150 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011
10.0.0.160 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011

#不支持,所以输出了hello > /root/hello.log到屏幕,而没有把hello写入到文件中
[root@master ~]#ansible webservers -m command  -a 'echo hello > /root/hello.log'
10.0.0.150 | CHANGED | rc=0 >>
hello > /root/hello.log
10.0.0.160 | CHANGED | rc=0 >>
hello > /root/hello.log

#creates存在则不执行
[root@master ~]#ansible webservers -m command  -a  'chdir=/etc creates=centos-release  cat centos-release'
10.0.0.150 | SUCCESS | rc=0 >>
skipped, since centos-release exists
10.0.0.160 | SUCCESS | rc=0 >>
skipped, since centos-release exists

#creates不存在则执行
[root@master ~]#ansible webservers -m command  -a  'chdir=/etc creates=f1.txt cat centos-release'
10.0.0.150 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011
10.0.0.160 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011


#removes存在才执行
[root@master ~]#ansible webservers -m command  -a  'chdir=/etc removes=centos-release  cat centos-release'
10.0.0.150 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011
10.0.0.160 | CHANGED | rc=0 >>
CentOS Linux release 8.3.2011

#removes不存在不执行
[root@master ~]#ansible webservers -m command  -a  'chdir=/etc removes=centos-rease  cat centos-release'
10.0.0.150 | SUCCESS | rc=0 >>
skipped, since centos-rease does not exist
10.0.0.160 | SUCCESS | rc=0 >>
skipped, since centos-rease does not exist

[root@master ~]#ansible webservers -m command  -a  'service mariadb restart'
[WARNING]: Consider using the service module rather than running 'service'.  If you
need to use command because service is insufficient you can add 'warn: false' to this
command task or set 'command_warnings=False' in ansible.cfg to get rid of this message.
10.0.0.160 | CHANGED | rc=0 >>
Redirecting to /bin/systemctl restart mariadb.service
10.0.0.150 | CHANGED | rc=0 >>
Redirecting to /bin/systemctl restart mariadb.service


2)shell模块
功能:和command相似,用shell执行命令,支持各种符号,比如:*,$, > 
说明:此模块不具有幂等性
说明:调用bash执行命令 类似 cat /tmp/test.md | awk -F'|' '{print $1,$2}' &> /tmp/example.txt 这些
复杂命令,即使使用shell也可能会失败,解决办法:写到脚本时,copy到远程,执行,再把需要的结果
拉回执行命令的机器

[root@master ~]#ansible webservers -m shell -a 'echo $HOSTNAME'
10.0.0.150 | CHANGED | rc=0 >>
master
10.0.0.160 | CHANGED | rc=0 >>
slave1

[root@master ~]#ansible webservers -m shell -a  'echo hello > /root/hello.log'
10.0.0.150 | CHANGED | rc=0 >>

10.0.0.160 | CHANGED | rc=0 >>

[root@master ~]#ansible webservers -m shell -a  'cat /root/hello.log'
10.0.0.150 | CHANGED | rc=0 >>
hello
10.0.0.160 | CHANGED | rc=0 >>
hello

可以把shell模块设置为默认模块
[root@master ~]#vim ansible.cfg
module_name = shell

Ansible 的配置文件可以放在多个不同地方,优先级从高到低顺序如下
ANSIBLE_CONFIG #环境变量,注意此项用 ansible --version 看不到,但可以生效
./ansible.cfg   #当前目录下的ansible.cfg
~/.ansible.cfg #当前用户家目录下的.ansible.cfg
/etc/ansible/ansible.cfg  #系统默认配置文件

3)script模块
功能:在远程主机上运行ansible服务器上的脚本(无需执行权限)
说明:此模块不具有幂等性
脚本在当前机器上
[root@master ~]#ansible webservers  -m script -a '/root/test.sh'


4)copy模块
功能:从主控端复制文件到远程主机
说明: src=file 如果是没指明路径,则为当前目录或当前目录下的files目录下的file文件
#如目标存在,默认覆盖,此处指定先备份
[root@master ~]#ansible webservers -m copy -a "src=/root/test.sh dest=/tmp/test3.sh owner=mysql  mode=600 backup=yes"

#指定内容,直接生成目标文件    
[root@master ~]#ansible webservers -m copy -a "content='test line1\ntest line2\n' dest=/tmp/test.txt"
[root@master ~]#cat /tmp/test.txt
test line1
test line2

#复制/etc目录自身,注意/etc/后面没有/
ansible webservers -m copy -a "src=/etc dest=/backup"

#复制/etc/下的文件,不包括/etc/目录自身,注意/etc/后面有/
ansible webservers -m copy -a "src=/etc/ dest=/backup"

5)get_url模块
功能: 用于将文件从http、https或ftp下载到被管理机节点上
常用参数:
url: 下载文件的URL,支持HTTP,HTTPS或FTP协议
dest: 下载到目标路径(绝对路径),如果目标是一个目录,就用服务器上面文件的名称,如果目标设置了名称就用目标设置的名称
owner:指定属主
group:指定属组
mode:指定权限
force: 如果yes,dest不是目录,将每次下载文件,如果内容改变,替换文件。如果否,则只有在目标不存在时才会下载该文件
checksum: 对目标文件在下载后计算摘要,以确保其完整性
           示例: checksum="sha256:D98291AC[...]B6DC7B97",
               checksum="sha256:http://example.com/path/sha256sum.txt"
url_username: 用于HTTP基本认证的用户名。 对于允许空密码的站点,此参数可以不使用`url_password'
url_password: 用于HTTP基本认证的密码。 如果未指定`url_username'参数,则不会使用`url_password'参数validate_certs:如果“no”,SSL证书将不会被验证。 适用于自签名证书在私有网站上使用
timeout: URL请求的超时时间,秒为单位

[root@master ~]#ansible webservers -m get_url -a 'url=http://nginx.org/download/nginx-1.18.0.tar.gz dest=/usr/local/src/nginx.tar.gz checksum="md5:b2d33d24d89b8b1f87ff5d251aa27eb8"'
[root@master ~]#ll /usr/local/src/nginx.tar.gz
-rw-r--r-- 1 root root 1039530 Nov 11 17:57 /usr/local/src/nginx.tar.gz


6)fethch模块
功能:从远程主机提取文件至ansible的主控端,copy相反,目前不支持目录
[root@master ~]#ansible webservers -m fetch -a 'src=/root/test.sh dest=.'

[root@master ~]#tree
.
├── 10.0.0.150
│   └── root
│       └── test.sh
├── 10.0.0.160
│   └── root
│       └── test.sh


7)file模块
功能:设置文件属性,创建软链接等
#创建空文件
[root@master ~]#ansible all -m file  -a 'path=/data/test.txt state=touch'
#删除文件
[root@master ~]#ansible all -m file  -a 'path=/data/test.txt state=absent'
#设置文件权限
[root@master ~]#ansible all -m file -a "path=/root/test.sh owner=wang mode=755"
#创建目录
[root@master ~]#ansible all -m file -a "path=/data/mysql state=directory owner=mysql group=mysql"
#创建软链接,path|dest|name表示三个选一个都行
[root@master ~]#ansible all -m file -a 'src=/data/testfile path|dest|name=/data/testfile-link state=link'
#创建目录
[root@master ~]#ansible all -m file  -a 'path=/data/testdir state=directory'
#递归修改目录属性,但不递归至子目录
[root@master ~]#ansible all -m file -a "path=/data/mysql state=directory owner=mysql group=mysql"
#递归修改目录及子目录的属性
[root@master ~]#ansible all -m file -a "path=/data/mysql state=directory owner=mysql group=mysql recurse=yes"

8)stat模块
功能:检查文件或文件系统的状态
说明:对于Windows目标,请改用win_stat模块
选项:path:文件/对象的完整路径(必须)
常用的返回值判断:
	exists: 判断是否存在
	isuid: 调用用户的ID与所有者ID是否匹配
[root@master data]#ansible 127.0.0.1 -m stat -a 'path=/etc/passwd'
127.0.0.1 | SUCCESS => {
    "changed": false,
    "stat": {
        "atime": 1636603261.996736,
        "attr_flags": "",
        "attributes": [],
        "block_size": 4096,
        "blocks": 8,
        "charset": "us-ascii",
        "checksum": "358721bb9ccdb8b1eaf3a9b97e51d1eee306dd50",
        "ctime": 1636429959.9657238,
        "dev": 2053,
        "device_type": 0,
        "executable": false,
        "exists": true,
        "gid": 0,
        "gr_name": "root",
        "inode": 135872481,
        "isblk": false,
        "ischr": false,
        "isdir": false,
        "isfifo": false,
        "isgid": false,
        "islnk": false,
        "isreg": true,
        "issock": false,
        "isuid": false,
        "mimetype": "text/plain",
        "mode": "0644",
        "mtime": 1636429959.9647236,
        "nlink": 1,
        "path": "/etc/passwd",
        "pw_name": "root",
        "readable": true,
        "rgrp": true,
        "roth": true,
        "rusr": true,
        "size": 2814,
        "uid": 0,
        "version": "4213724205",
        "wgrp": false,
        "woth": false,
        "writeable": true,
        "wusr": true,
        "xgrp": false,
        "xoth": false,
        "xusr": false
    }
}

使用范例一:
- name: install | Check if file is already configured.
 stat: path={{ nginx_file_path }}
 connection: local
 register: nginx_file_result
- name: install | Download nginx file
 get_url: url={{ nginx_file_url }} dest={{ software_files_path }} validate_certs=no
 connection: local
 when:,not. nginx_file_result.stat.exists
使用范例二:
[root@ansible ansible]#cat stat.yml
---
- hosts: websrvs
  
 tasks:
    - name: check file
     stat: path=/data/mysql 
     register: st
    - name: debug
     debug:
       msg: "/data/mysql is not exist"
     when: not st.stat.exists
     
     
9)unarchive模块
功能:解包解压缩
实现有两种用法:
1、将ansible主机上的压缩包传到远程主机后解压缩至特定目录,设置copy=yes,此为默认值,可省略
2、将远程主机上的某个压缩包解压缩到指定路径下,设置copy=no 
常见参数:
copy:默认为yes,当copy=yes,拷贝的文件是从ansible主机复制到远程主机上,如果设置为copy=no,会在远程主机上寻找src源文件
remote_src:和copy功能一样且互斥,yes表示在远程主机,不在ansible主机,no表示文件在ansible主机上
src:源路径,可以是ansible主机上的路径,也可以是远程主机(被管理端或者第三方主机)上的路径,如果是远程主机上的路径,则需要设置copy=no
dest:远程主机上的目标路径
mode:设置解压缩后的文件权限

[root@master ~]#ansible all -m unarchive -a 'src=/data/foo.tgz dest=/var/lib/foo owner=wang group=bin'
[root@master ~]#ansible all -m unarchive -a 'src=/tmp/foo.zip dest=/data copy=no mode=0777'
[root@master ~]#ansible all -m unarchive -a 'src=https://releases.ansible.com/ansible/ansible-2.1.6.0-0.1.rc1.tar.gz dest=/data copy=no'
[root@master ~]#ansible all -m unarchive -a 'src=https://releases.ansible.com/ansible/ansible-2.1.6.0-0.1.rc1.tar.gz dest=/data/   owner=root remote_src=yes'
[root@master ~]#ansible all -m unarchive -a 'src=http://nginx.org/download/nginx-1.18.0.tar.gz dest=/usr/local/src/ copy=no'


10)archive模块
功能:打包压缩保存在被管理节点

[root@master ~]#ansible all -m archive -a 'path=/root/nginx-1.18.0  dest=/root/ngxin.tar.bz2 format=bz2  mode=0600'


11)hostname模块
功能:管理主机名
[root@master ~]#ansible 10.0.0.150 -m hostname -a 'name=master111'


12)cron模块
功能:计划任务
支持时间:minute,hour,day,month,weekday

[root@master ~]#cat /root/mysql_backup.sh 
#!/bin/bash
mysqldump -A -F --single-transaction --master-data=2 -q -uroot |gzip > 
/data/mysql_`date +%F_%T`.sql.gz
#创建任务
[root@master ~]#ansible 10.0.0.150 -m cron -a 'hour=2 minute=30 weekday=1-5 name="backup mysql" job=/root/mysql_backup.sh'
[root@master ~]#ansible websrvs   -m cron -a "minute=*/5 job='/usr/sbin/ntpdate ntp.aliyun.com &>/dev/null' name=Synctime"
#禁用计划任务
[root@master ~]#ansible websrvs   -m cron -a "minute=*/5 job='/usr/sbin/ntpdate 172.20.0.1 &>/dev/null' name=Synctime disabled=yes"
#启用计划任务
[root@master ~]#ansible websrvs   -m cron -a "minute=*/5 job='/usr/sbin/ntpdate 172.20.0.1 &>/dev/null' name=Synctime disabled=no"
#删除任务
[root@master ~]#ansible websrvs -m cron -a "name='backup mysql' state=absent"
[root@master ~]#ansible websrvs -m cron -a 'state=absent name=Synctime'

13)yum和apt模块
功能:
yum 管理软件包,只支持RHEL,CentOS,fedora,不支持Ubuntu其它版本
apt 模块管理 Debian 相关版本的软件包
[root@master ~]#ansible websrvs -m yum -a 'name=httpd state=present'  #安装
[root@master ~]#ansible websrvs -m yum -a 'name=nginx state=present enablerepo=epel'  #启用epel源进行安装
[root@master ~]#ansible websrvs -m yum -a 'name=* state=lastest exclude=kernel*,foo*' #升级除kernel和foo开头以外的所有包
[root@master ~]#ansible websrvs -m yum -a 'name=httpd state=absent'   #删除
[root@master ~]#ansible websrvs -m yum -a 'name=sl,cowsay'
[root@master ~]#ansible websrvs -m yum -a 
"name=https://mirror.tuna.tsinghua.edu.cn/zabbix/zabbix/5.2/rhel/7/x86_64/zabbixagent-5.2.5-1.el7.x86_64.rpm"
[root@centos8 ~]#ansible websrvs -m apt -a 'name=rsync,psmisc state=absent'
[root@master ~]#ansible localhost -m yum -a "list=tree"

14)yum_repository模块
功能:配置yum仓库
#创建yum仓库
[root@master ~]#ansible localhost -m yum_repository  -a "name=test description='epel yum repo' file=external_repos baseurl=https://download.fedoraproject.org/pub/epel/$releasever/$basearch/ gpgcheck=no"
localhost | CHANGED => {
    "changed": true,
    "repo": "test",
    "state": "present"
}

[root@master ~]#ls /etc/yum.repos.d/external_repos.repo
/etc/yum.repos.d/external_repos.repo

#删除仓库
[root@master ~]#ansible localhost -m yum_repository  -a "name=test  file=external_repos state=absent"                                                                           localhost | CHANGED => {
    "changed": true,
    "repo": "test",
    "state": "absent"
}
[root@master ~]#ls /etc/yum.repos.d/external_repos.repo                                 ls: cannot access '/etc/yum.repos.d/external_repos.repo': No such file or directory

15)service模块
功能:管理服务
[root@master ~]#ansible all -m service -a 'name=httpd state=started enabled=yes'
[root@master ~]#ansible all -m service -a 'name=httpd state=stopped'
[root@master ~]#ansible all -m service -a 'name=httpd state=reloaded'
[root@master ~]#ansible all -m shell -a "sed -i 's/^Listen 80/Listen 8080/' 
/etc/httpd/conf/httpd.conf"
[root@master ~]#ansible all -m service -a 'name=httpd state=restarted'


16)user模块
功能:管理用户
#创建用户
[root@master ~]#ansible all -m user -a 'name=nginx comment=nginx uid=88  groups="root,daemon" shell=/sbin/nologin system=yes create_home=no home=/data/nginx non_unique=yes'

#remove=yes表示删除用户及家目录等数据,默认remove=no
[root@master ~]#ansible all -m user -a 'name=nginx state=absent remove=yes'

#生成123456加密的密码
[root@master ~]#ansible localhost -m debug -a "msg={{ '123456'| 
password_hash('sha512','salt')}}"
localhost | SUCCESS => {
    "msg": "$6$salt$MktMKPZJ6t59GfxcJU20DwcwQzfMvOlHFVZiOVD71w."
}
#用上面创建的密码创建用户
[root@master ~]#ansible websrvs -m user -a 'name=test password="$6$salt$MktMKPZJ6t59GfxcJU20DwcwQzfMvOlHFVZiOVD71w."'

#创建用户test,并生成4096bit的私钥
[root@master ~]#ansible websrvs -m user -a 'name=test generate_ssh_key=yes ssh_key_bits=4096 ssh_key_file=.ssh/id_rsa'

17)group模块
功能:管理组
#创建组
[root@master ~]#ansible websrvs -m group  -a 'name=nginx gid=88 system=yes'
#删除组
[root@master ~]#ansible websrvs -m group  -a 'name=nginx state=absent'


18)lineinfile模块
ansible在使用sed进行替换时,经常会遇到需要转义的问题,而且ansible在遇到特殊符号进行替换时,存在问题,无法正常进行替换 。其实在ansible自身提供了两个模块:lineinfile模块和replace模块,可以方便的进行替换

一般在ansible当中去修改某个文件的单行进行替换的时候需要使用lineinfile模块

regexp参数 :使用正则表达式匹配对应的行,当替换文本时,如果有多行文本都能被匹配,则只有最后面被匹配到的那行文本才会被替换,当删除文本时,如果有多行文本都能被匹配,这么这些行都会被删除。

如果想进行多行匹配进行替换需要使用replace模块

功能:相当于sed,可以修改文件内容

[root@master ~]#ansible websrvs -m lineinfile -a "path=/etc/httpd/conf/httpd.conf regexp='^Listen' line='Listen 80'"
[root@master ~]#ansible all -m   lineinfile -a "path=/etc/selinux/config regexp='^SELINUX=' line='SELINUX=disabled'"
[root@master ~]#ansible all -m lineinfile  -a 'dest=/etc/fstab state=absent regexp="^#"'

19)replace模块
该模块有点类似于sed命令,主要也是基于正则进行匹配和替换,建议使用
[root@master ~]#ansible all -m replace -a "path=/etc/fstab regexp='^(UUID.*)' replace='#\1'"  
[root@master ~]#ansible all -m replace -a "path=/etc/fstab regexp='^#(UUID.*)' replace='\1'"


20)SELinux 模块
该模块管理 SELInux 策略
[root@master ~]#ansible all -m selinux -a 'state=disabled'


21)reboot模块
功能:重启服务器
[root@master ~]#ansible websrvs -m reboot


22)mount 挂载和卸载
功能: 挂载和卸载文件系统
#临时挂载
[root@master ~]#mount 10.0.0.150 -m mount -a 'src="UUID=b3e48f45-f933-4c8e-a700-22a159ec9077" path=/home fstype=xfs opts=noatime state=present'
#临时取消挂载
[root@master ~]#mount all -m mount -a 'path=/home fstype=xfs opts=noatime state=unmounted'
#永久挂载
[root@master ~]#ansible all -m mount -a 'src=10.0.0.150:/data/wordpress path=/var/www/html/wp-content/uploads opts="_netdev" state=mounted'
#永久卸载
[root@master ~]#ansible all -m mount -a 'src=10.0.0.150:/data/wordpress path=/var/www/html/wp-content/uploads state=absent'

23)Setup 模块
功能: setup 模块来收集主机的系统信息,这些 facts 信息可以直接以变量的形式使用,但是如果主机较多,会影响执行速度
可以使用 gather_facts: no 来禁止 Ansible 收集 facts 信息

[root@master ~]#ansible all -m setup
[root@master ~]#ansible all -m setup -a "filter=ansible_nodename"
[root@master ~]#ansible all -m setup -a "filter=ansible_hostname"
[root@master ~]#ansible all -m setup -a "filter=ansible_domain"
[root@master ~]#ansible all -m setup -a "filter=ansible_memtotal_mb"
[root@master ~]#ansible all -m setup -a "filter=ansible_memory_mb"
[root@master ~]#ansible all -m setup -a "filter=ansible_memfree_mb"
[root@master ~]#ansible all -m setup -a "filter=ansible_os_family"
[root@master ~]#ansible all -m setup -a "filter=ansible_distribution_major_version"
[root@master ~]#ansible all -m setup -a "filter=ansible_distribution_version"
[root@master ~]#ansible all -m setup -a "filter=ansible_processor_vcpus"
[root@master ~]#ansible all -m setup -a "filter=ansible_all_ipv4_addresses"
[root@master ~]#ansible all -m setup -a "filter=ansible_architecture"
[root@master ~]#ansible all -m setup -a "filter=ansible_uptime_seconds"
[root@master ~]#ansible all -m setup -a "filter=ansible_processor*"
[root@master ~]#ansible all -m setup -a 'filter=ansible_env'
[root@master ~]#ansible all -m setup -a 'filter=ansible_all_ipv4_addresses'
[root@master ~]#ansible all -m setup -a 'filter=ansible_python_version'
[root@master ~]#ansible all -m setup -a 'filter="ansible_default_ipv4"'

24)debug 模块
此模块可以用于输出信息,并且通过 msg 定制输出的信息内容
注意: msg后面的变量有时需要加 " " 引起来

debug 模块默认输出Hello world
[root@master ~]#ansible all -m debug
10.0.0.150 | SUCCESS => {
    "msg": "Hello world!"
}

[root@master ~]#ansible all -m debug -a 'msg="HOSTNAME"'
10.0.0.150 | SUCCESS => {
    "msg": "HOSTNAME"
}

#利用debug模块输出变量
[root@master ~]#cat debug.yaml 
---
- hosts: websrvs
  
 tasks: 
    - name: output variables
     debug:
       msg: Host "{{ ansible_nodename }}" Ip  "{{ ansible_default_ipv4.address }}"

#显示特定字符
# cat debug.yml
- hosts: all
 gather_facts: no
 vars:
   a: "12345"
 tasks:
  - debug:
     msg: "{{a[2]}}"
#定义了一个字符串变量a,如果想要获取a字符串的第3个字符,则可以使用”a[2]”获取,索引从0开始,执行上例playbook,debug的输出信息如下:

[root@master tasks]#ansible-playbook /root/debug.yml

PLAY [all] *****************************************************************************

TASK [debug] ***************************************************************************
ok: [10.0.0.150] => {
    "msg": "3"
}
ok: [10.0.0.160] => {
    "msg": "3"
}


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