Zabbix 5.0 LTS版本的安裝小結
1:准備Zabbix的服務器。
這里可能需要一台或多台服務器，視需求和資源而定。也可以將Zabbix_Server、MySQL、Zabbix Web等安裝在同一台服務器上。
這里我們打算安裝在一台測試服務器上。操作系統版本為CentOS Linux release 8.2.2004 (Core)。
環境要求
Zabbix 5.0 版本對基礎環境的要求有大的變化，最大的就是對 php 版本的要求，最低要求 7.2.0 版本,對 php 擴展組件版本也有要求，詳見官網文檔https://www.zabbix.com/documentation/current/manual/installation/requirements。 這里有對硬件資源、操作系統、數據庫版本等相關的規范要求。
2：關閉SELINXU
如果想關閉SeLinux,又不想重啟服務器，那么使用下面命令。但是該命令只能將SeLinux在enforcing、permissive這兩種模式之間切換.服務器重啟后,又會恢復到/etc/selinux/config下的設置,也就是說setenforce的修改是不能持久的。
# setenforce 0
# getenforce
所以你想永久關閉SeLinux的話，還是必須調整/etc/selinux/config下的參數。
# vi /etc/selinux/config
將SELINUX=enforcing調整為SELINUX=disabled 或Permissive
你也可以使用shell腳本修改參數
# getenforce
Enforcing
# sed -i 's/SELINUX=enforcing/SELINUX=disabled/' /etc/selinux/config
調整完參數后，最好重啟一下服務器
3：安裝MySQL數據庫
Zabbix支持MySQL、PostgreSQL、Oracle 等數據庫，另外MySQL數據庫可以用MySQL社區版或MariaDB。具體的版本要求為：MySQL.5.62 - 8.0.x ，如果是MariaDB則要求10.0.37或后續版本。
下面我們打算安裝MySQL社區版。yum安裝方式的簡單過程如下：
安裝MySQL Repository
#rpm -ivh https://dev.mysql.com/get/mysql80-community-release-el8-1.noarch.rpm
驗證MySQL Repository是否安裝
#yum repolist all | grep mysql | grep enabled
[root@appliance ~]# yum repolist all | grep mysql | grep enabled
mysql-connectors-community MySQL Connectors Community enabled
mysql-tools-community MySQL Tools Community enabled
mysql80-community MySQL 8.0 Community Server enabled
Yum方式安裝MySQL
#yum --disablerepo=AppStream install -y mysql-community-server
#systemctl enable mysqld #設置開機啟動MySQL
#systemctl start mysqld #啟動MySQL服務
#systemctl status mysqld #檢查MySQL服務狀態
獲取MySQL root的臨時密碼
[root@appliance ~]# cat /var/log/mysqld.log | grep -i 'temporary password'
2020-07-02T07:37:04.495297Z 6 [Note] [MY-010454] [Server] A temporary password is generated for root@localhost: AgI<w+2,hwyW
[root@appliance ~]#
執行mysql_secure_installation安全配置向導來做一些常規化安全設置
[root@appliance ~]# mysql_secure_installation
Securing the MySQL server deployment.
Enter password for user root:
The existing password for the user account root has expired. Please set a new password.
New password:
Re-enter new password:
The 'validate_password' component is installed on the server.
The subsequent steps will run with the existing configuration
of the component.
Using existing password for root.
Estimated strength of the password: 100
Change the password for root ? ((Press y|Y for Yes, any other key for No) : YES
New password:
Re-enter new password:
Estimated strength of the password: 100
Do you wish to continue with the password provided?(Press y|Y for Yes, any other key for No) : y
By default, a MySQL installation has an anonymous user,
allowing anyone to log into MySQL without having to have
a user account created for them. This is intended only for
testing, and to make the installation go a bit smoother.
You should remove them before moving into a production
environment.
Remove anonymous users? (Press y|Y for Yes, any other key for No) : y
Success.
Normally, root should only be allowed to connect from
'localhost'. This ensures that someone cannot guess at
the root password from the network.
Disallow root login remotely? (Press y|Y for Yes, any other key for No) : y
Success.
By default, MySQL comes with a database named 'test' that
anyone can access. This is also intended only for testing,
and should be removed before moving into a production
environment.
Remove test database and access to it? (Press y|Y for Yes, any other key for No) : y
- Dropping test database...
Success.
- Removing privileges on test database...
Success.
Reloading the privilege tables will ensure that all changes
made so far will take effect immediately.
Reload privilege tables now? (Press y|Y for Yes, any other key for No) : y
Success.
All done!
因為規划將MySQL的數據庫放在/mysql下面，所以我們還需要移動MySQL的datadir到/mysql下，關於如何移動MySQL數據庫存儲目錄，參考我這篇博客“CentOS 7上更改MySQL數據庫存儲目錄淺析。” 這里就不展開介紹細節信息了。
如果要安裝MariaDB也非常簡單。使用下面命令即可快捷方便的安裝MariaDB
yum install mariadb-server -y
4：安裝Zabbix Repository
#rpm -Uvh https://repo.zabbix.com/zabbix/5.0/rhel/8/x86_64/zabbix-release-5.0-1.el8.noarch.rpm
#dnf clean all
[root@appliance mysql]# rpm -Uvh https://repo.zabbix.com/zabbix/5.0/rhel/8/x86_64/zabbix-release-5.0-1.el8.noarch.rpm
Retrieving https://repo.zabbix.com/zabbix/5.0/rhel/8/x86_64/zabbix-release-5.0-1.el8.noarch.rpm
warning: /var/tmp/rpm-tmp.Am4Zqr: Header V4 RSA/SHA512 Signature, key ID a14fe591: NOKEY
Verifying... ################################# [100%]
Preparing... ################################# [100%]
Updating / installing...
1:zabbix-release-5.0-1.el8 ################################# [100%]
[root@appliance mysql]# dnf clean all
28 files removed
5：安裝Zabbix Server、Zabbix Agent、Zabbix Web
Nginx
dnf install zabbix-server-mysql zabbix-web-mysql zabbix-nginx-conf zabbix-agent
Apache
# dnf install zabbix-server-mysql zabbix-web-mysql zabbix-apache-conf zabbix-agent
6：初始化Zabbix的數據庫
# mysql -uroot -p
password #輸入具體的賬號密碼
mysql> create database zabbix character set utf8 collate utf8_bin;
mysql> create user zabbix@localhost identified by 'xxxxx'; #實際情況中，輸入具體的賬號密碼(這里在某些數據庫版本有個坑，后面講述這個坑)
mysql> grant all privileges on zabbix.* to zabbix@localhost;
mysql> quit;
導入Zabbix數據庫結構和數據
# zcat /usr/share/doc/zabbix-server-mysql*/create.sql.gz | mysql -uzabbix -p zabbix
7：配置Zabbix Server連接數據庫設置
/etc/zabbix/zabbix_server.conf
一般情況執行配置DBPassword,但是如果你修改了一些默認配置，那么還需設置一些其他參數。例如DBSocket、DBPort等等。
### Option: DBHost
# Database host name.
# If set to localhost, socket is used for MySQL.
# If set to empty string, socket is used for PostgreSQL.
#
# Mandatory: no
# Default:
# DBHost=localhost
DBHost=localhost
### Option: DBName
# Database name.
#
# Mandatory: yes
# Default:
# DBName=
DBName=zabbix
### Option: DBPassword
# Database password.
# Comment this line if no password is used.
#
# Mandatory: no
# Default:
# DBPassword=
DBPassword=xxxxxx
### Option: DBSocket
# Path to MySQL socket.
#
# Mandatory: no
# Default:
# DBSocket=
DBSocket=/mysql_data/mysql/mysql.sock
這里要根據實際情況進行配置，有些參數也可以不配置。有些參數，例如DBSocket，我修改過MySQL數據庫的數據文件目錄，所以這里必須修改。否則后面會遇到一些錯誤。
8：Zabbix前端的PHP配置
/etc/php-fpm.d/zabbix.conf
參數date.timezone的默認配置如下，一般我們必須取消注釋，將時區修改為Asia/Shanghai
; php_value[date.timezone] = Europe/Riga
9： 修改nginx或Apache的配置
/etc/nginx/conf.d/zabbix.conf 配置端口和指定server_name的IP地址
listen 80;
server_name xxx.xxx.xxx.xx;
如果是Apache暫時不用設置任何配置。
10：設置防火牆端口
#firewall-cmd --permanent --add-port=10050/tcp
#firewall-cmd --permanent --add-port=10051/tcp
#firewall-cmd --permanent --add-port=80/tcp
#firewall-cmd --reload
10: 啟動服務並將其設置為開機自啟動
Nginx
# systemctl restart zabbix-server zabbix-agent nginx php-fpm
# systemctl enable zabbix-server zabbix-agent nginx php-fpm
Apache
#systemctl restart zabbix-server zabbix-agent httpd php-fpm
#systemctl enable zabbix-server zabbix-agent httpd php-fpm
11：http://xxx.xxx.xxx.xxx/ 進入設置界面。
Nginx
http://192.168.xxx.xxx/setup.php
Apache
http://192.168.xxx.xxx/zabbix/setup.php
配置完成后，登錄系統修改賬號密碼，禁用一些賬號。然后就可以開始使用Zabbix了。
問題小結
1：導入Zabbix數據庫結構和數據時遇到告警：“No database selected”
安裝測試過兩次，有一次遇到下面錯誤“No database selected”，解決辦法是，在create.sql.gz中加入一行SQL：
[root@appliance ~]# zcat /usr/share/doc/zabbix-server-mysql*/create.sql.gz | mysql -uzabbix -p
Enter password:
ERROR 1046 (3D000) at line 1: No database selected
可以先解壓gz文件，加入use zabbix;這一句SQL，或者直接使用vim編輯gz文件文件
# vim create.sql.gz
其實出現上面錯誤，是因為腳本沒有指定數據庫，如下書寫即可避免這個問題。你也可以通過參數 -D指定數據庫。
# zcat /usr/share/doc/zabbix-server-mysql*/create.sql.gz | mysql -uzabbix -p zabbix
2：配置DB Connection過程遇到“Cannot Connect to the Database"錯誤
檢查Zabbix Server的日志，發現如下錯誤信息。
19690:20200702:184818.882 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
19690:20200702:184818.882 database is down: reconnecting in 10 seconds
19690:20200702:184828.883 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
19690:20200702:184828.883 database is down: reconnecting in 10 seconds
19690:20200702:184838.883 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
19690:20200702:184838.883 database is down: reconnecting in 10 seconds
19690:20200702:184848.884 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
19690:20200702:184848.884 database is down: reconnecting in 10 seconds
19690:20200702:184858.884 [Z3001] connection to database 'zabbix' failed: [2002] Can't connect to local MySQL server through socket '/var/lib/mysql/mysql.sock' (2)
19690:20200702:184858.884 database is down: reconnecting in 10 seconds
這個是Zabbix Server連接MySQL有問題。因為我移動過MySQL的數據目錄，所以需要修改/etc/zabbix/zabbix_server.conf文件下的參數DBScoket，如下所示
然后Zabbix Server的錯誤日志中上述錯誤消失，但是依然報這個錯誤，如下截圖所示， 此時必須將Database Host從localhost改為127.0.0.1
問題解決后，登錄系統，修改Zabbix用戶密碼。
3：配置DB Connection過程遇到“Cannot Connect to the Database"錯誤，如下截圖所示：
檢查Zabbix Server的日志，tail -80f /var/log/zabbix/zabbix_server.log 如下所示,提示下面錯誤
63446:20200707:141746.072 Starting Zabbix Server. Zabbix 5.0.1 (revision c2a0b03480).
63446:20200707:141746.073 ****** Enabled features ******
63446:20200707:141746.073 SNMP monitoring: YES
63446:20200707:141746.073 IPMI monitoring: YES
63446:20200707:141746.073 Web monitoring: YES
63446:20200707:141746.073 VMware monitoring: YES
63446:20200707:141746.073 SMTP authentication: YES
63446:20200707:141746.073 ODBC: YES
63446:20200707:141746.073 SSH support: YES
63446:20200707:141746.073 IPv6 support: YES
63446:20200707:141746.073 TLS support: YES
63446:20200707:141746.073 ******************************
63446:20200707:141746.073 using configuration file: /etc/zabbix/zabbix_server.conf
63446:20200707:141746.080 [Z3001] connection to database 'zabbix' failed: [2059] Plugin caching_sha2_password could not be loaded: lib64/mariadb/plugin/caching_sha2_password.so: cannot open shared object file: No such file or directory
63446:20200707:141746.080 Cannot connect to the database. Exiting
這個是因為MySQL 8數據庫的加密方式改變了，可以設置參數default_authentication_plugin='mysql_native_password'，使用舊版本中的認證方式。當然也可以使用下面方式修改一下賬號
mysql> select version();
+-----------+
| version() |
+-----------+
| 8.0.20 |
+-----------+
1 row in set (0.00 sec)
mysql> show variables like 'default_authentication_plugin';
+-------------------------------+-----------------------+
| Variable_name | Value |
+-------------------------------+-----------------------+
| default_authentication_plugin | caching_sha2_password |
+-------------------------------+-----------------------+
1 row in set (0.01 sec)
mysql> select host,user,plugin from mysql.user;
+-----------+------------------+-----------------------+
| host | user | plugin |
+-----------+------------------+-----------------------+
| localhost | mysql.infoschema | caching_sha2_password |
| localhost | mysql.session | caching_sha2_password |
| localhost | mysql.sys | caching_sha2_password |
| localhost | root | caching_sha2_password |
| localhost | zabbix | caching_sha2_password |
+-----------+------------------+-----------------------+
5 rows in set (0.00 sec)
mysql> alter user 'zabbix'@'localhost' identified with mysql_native_password by 'xxxxxx';
Query OK, 0 rows affected (0.02 sec)
mysql>
之所以遇到這種問題，是因為上面創建賬號時，使用的是下面這個SQL引起
mysql> create user zabbix@localhost identified by 'xxxxx';
參考資料：
https://www.zabbix.com/documentation/current/manual/installation/install#installing_frontend
https://www.itzgeek.com/how-tos/linux/centos-how-tos/how-to-install-zabbix-server-on-centos-8-rhel-8.html
https://www.zabbix.com/cn/download?zabbix=5.0&os_distribution=centos&os_version=8&db=mysql&ws=apache
https://www.itzgeek.com/how-tos/linux/centos-how-tos/how-to-install-mysql-8-0-on-rhel-8.html
https://bobcares.com/blog/zabbix-cannot-connect-to-the-database/
http://www.zsythink.net/archives/500