Linux System Learning Eighth day-<< engineer Technology >>

Two virtual machines, both fire and hostname modified

Virtual Machine Server0:
# Firewall-cmd--set-default-zone=trusted
# echo server0.example.com >/etc/hostname
# Cat/etc/hostname

Virtual Machine desktop0:
# Firewall-cmd--set-default-zone=trusted
# echo desktop0.example.com >/etc/hostname
# Cat/etc/hostname

? Basic features of the e-mail server
– Provide users with an e-mail storage space (username @ mail domain name)
– Process user-sent messages-delivered to the receiving server
– Process messages received by users--post to mailbox

Protocol for users to send mail: SMTP port 25
User-received mail protocol: POP3 Port 143 IMAP Port

######################################################
Virtual Machine Server0
Building a Basic mail server
1. Installing the Postfix service-side program
[Email protected] ~]# rpm-q postfix
Postfix-2.10.1-6.el7.x86_64

2. Configure the Postfix service, modify the configuration file
[Email protected] ~]# VIM/ETC/POSTFIX/MAIN.CF
76 Rows Myhostname = server0.example.com #指定主机名
83 Rows mydomain = example.com #指定域名
99 Rows Myorigin = Server0.example.com #默认补全的邮件后缀
116 rows inet_interfaces = All #允许所有客户端
164 Rows mydestination = server0.example.com
#判断邮件后缀为本域邮件
Added: Vim Command mode u undo

3. Restart Postfix service, set to boot from
# systemctl Restart Postfix
# Systemctl Enable Postfix

4. Test Mail Sending and receiving

[Email protected] ~]# Useradd YG
[Email protected] ~]# echo 123 | passwd--stdin YG

[Email protected] ~]# Useradd XLN
[Email protected] ~]# echo 123 | passwd--stdin XLN

? Mail sending operation
–mail-s ' message header '-R sender Recipient

? Mail receive operation
–mail [-u user Name]

[Email protected] ~]# mail-s ' test01 '-R YG Xln

There is only one "." In a row , the end of the representative

[Email protected] ~]# mail-u XLN
Enter message number 1 view message content
Quit quitting
#################################################

Nullclient Mail Service

Empty client
? Nullclient, empty Client
– No email account is available, so no mail is required
– but you can send a message to the user on behalf of

I. Configuring DESKTOP0 as a mail server
1. Configure the Postfix service, modify the configuration file
[Email protected] ~]# VIM/ETC/POSTFIX/MAIN.CF

99 Rows Myorigin = Desktop0.example.com
116 Rows inet_interfaces = All
164 Rows mydestination = desktop0.example.com

[Email protected] ~]# systemctl restart Postfix
[Email protected] ~]# Systemctl enable Postfix

Second, configure SERVER0 to be empty client mail server
[Email protected] ~]# VIM/ETC/POSTFIX/MAIN.CF

99 Rows Myorigin = Desktop0.example.com
116 row inet_interfaces = localhost
164 row Mydestination =
317 Rows Relayhost = [172.25.0.10] #指定交给邮件服务器IP地址

[Email protected] ~]# systemctl restart Postfix

Third, testing
On the virtual machine Server0
# echo ABC | Mail-s Test1-r YG Student

On the virtual machine desktop0
# Mail-u Student
######################################################
Database service Basics

? A common relational database management system
– Microsoft's SQL Server
–IBM's DB2
– Oracle, MySQL for Oracle
– Community Open Source version MariaDB

? MariaDB related packages in RHEL7
–mariadb-server: Provision of server-side related system programs
Port number: 3306

I. Deployment of the MARIADB database
1. Installing the Mariadb-server database software
[Email protected] ~]# yum-y install Mariadb-server

2. Start the MARIADB service
[Email protected] ~]# systemctl restart MARIADB
[Email protected] ~]# Systemctl enable MARIADB

##################################################

[[email protected] ~]# MySQL

MariaDB [(None)]> show databases; #查看数据库
MariaDB [(None)]> CREATE Database nsd1709; #创建数据库
MariaDB [(None)]> show databases;

MariaDB [(None)]> drop database nsd1709; #删除数据库
MariaDB [(None)]> show databases;

MariaDB [(None)]> CREATE Database nsd;
MariaDB [(None)]> show databases;

MariaDB [(None)]> quit #退出数据库

###################################################

The database administrator is root, but it does not matter to the system user root

? Change password for database account
–mysqladmin [-u user name] [-p[old password]] password ' new password '

[Email protected] ~]# mysqladmin-u root password ' 123 '

[[email protected] ~]# MySQL
ERROR 1045 (28000): Access denied for user ' root ' @ ' localhost ' (using Password:no)

[Email protected] ~]# mysql-u root-p
Enter Password:

[Email protected] ~]# mysql-u root-p123 #免交互登陆

? No monitoring, only for native
[Email protected] ~]# vim/etc/my.cnf #数据库主配置文件
[Mysqld]
Skip-networking #跳过网络监听
......
[Email protected] ~]# systemctl restart MARIADB

? MariaDB [(none)]> Interactive Instruction
– List database: show databases;
– Using/Selecting the database: Use database name;
– List What tables are in the library: show tables;
– Creating database: Create database name;
– Delete database: drop database name;

Http://172.25.254.254/pub/materials/users.sql

? Import/Restore to Database
–mysql [-u user name] [-p[password]] Database name < backup file. sql

# wget Http://172.25.254.254/pub/materials/users.sql
# mysql-u root-p123 NSD < Users.sql

# mysql-u Root-p123

MariaDB [nsd]> use NSD; #进入nsd库
MariaDB [nsd]> Show tables; #查看都有那些表格

######################################################

Query operations
# mysql-u Root-p123
MariaDB [nsd]> use NSD;

MariaDB [nsd]> SELECT * from base;
MariaDB [nsd]> SELECT * from location;

MariaDB [nsd]> Select Id,name from base;

MariaDB [nsd]> SELECT * from base where name= ' Tom ';

MariaDB [nsd]> SELECT * from location where city= ' Beijing ';

#######################################################
Database authorization

MariaDB [(none)]> Interactive Instruction
–grant permissions list on database name. Table name to User name @localhost
Identified by ' password ';

When the Lisi user logs in from local localhost, enter password 123, the library will get the query permissions for all tables NSD

# mysql-u Root-p123

MariaDB [(None)]> Grant Select on nsd.* to [e-mail protected] identified by ' 123 ';

View the user table information in the MARIADB database

MariaDB [mysql]> Select User,password from Mysql.user;

#####################################################
Case 5: Working with database queries

2. Use the database NSD on the system Server0 and use the phase
The SQL query that is expected to answer the following questions:

1) password is the name of the person who solicitous?

> select * from nsd.base where password= ' solicitous ';
> select * from nsd.base where password= ' solicitous ' and id= ' 3 ';

> select * from nsd.base where name= ' Barbara ' or id= ' 3 ';

2) How many people's names are Barbara while residing in Sunnyvale?

> Use NSD;

> select * from Base,location
where Base.name= ' Barbara ' and location.city= ' Sunnyvale ' and base.id=location.id;

> select COUNT (*) from base,location
where Base.name= ' Barbara ' and location.city= ' Sunnyvale ' and base.id=location.id;

> Insert Base VALUES (6, ' Barbara ', 123456); #插入表记录
> Insert Location VALUES (6, ' Sunnyvale '); #插入表记录
> select * from base;
> select * from location;

1. Disable null password root user access to MARIADB database

> Use MySQL;

> select User,host,password from user where password= ' and user= ' root ';

> Delete from user where password= ' and user= ' root ';

> select User,host,password from User;

> DESC User; #查看表结构

Linux System Learning Eighth day-<< engineer Technology >>