zabbix4.4 启动失败分析

zabbix是基于WEB界面提供分布式系统监视以及网络监视功能的企业级开源解决方案，能监视各种网络参数，保证服务器系统的安全运营；并提供灵活的通知机制以让系统管理员快速定位/解决存在的各种问题。
做为开源用户的支持者，我们大部分环境用的软件包含监控软件、数据库、继承应用、操作系统等都是用开源的，例如centos、PG、zabbix、openshift等，但是开源的在成熟度上是不错，但是安装软件有时比较麻烦，例如centos的安全开关，默认情况下会导致我们在安装openshift、zabbix等导致失败，而错误日志提示往往与实际十万三千里，但是有经验的在安装完系统后会有意识性的去修改配置，避免不必要的问题，
如下问题：
在安装配置好zabbix后无法正常启动，原因是SELINUX设置问题导致启动失败，
故障分析：
[root@localhost zabbix]# systemctl start zabbix-server.service
Job for zabbix-server.service failed because a configured resource limit was exceeded. See "systemctl status zabbix-server.service" and "journalctl -xe" for details.
[root@localhost zabbix]# journalctl -xe
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit zabbix-server.service has begun starting up.
1月 07 15:21:17 localhost.localdomain systemd[1]: PID file /run/zabbix/zabbix_server.pid not readable (yet?) after start.
1月 07 15:21:17 localhost.localdomain systemd[1]: zabbix-server.service never wrote its PID file. Failing.
1月 07 15:21:17 localhost.localdomain systemd[1]: Failed to start Zabbix Server.
-- Subject: Unit zabbix-server.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit zabbix-server.service has failed.
-- 
-- The result is failed.
1月 07 15:21:17 localhost.localdomain systemd[1]: Unit zabbix-server.service entered failed state.
1月 07 15:21:17 localhost.localdomain systemd[1]: zabbix-server.service failed.
1月 07 15:21:17 localhost.localdomain polkitd[804]: Unregistered Authentication Agent for unix-process:6787:8831344 (system bus name
1月 07 15:21:24 localhost.localdomain polkitd[804]: Registered Authentication Agent for unix-process:6797:8832061 (system bus name :
1月 07 15:21:27 localhost.localdomain systemd[1]: zabbix-server.service holdoff time over, scheduling restart.
1月 07 15:21:27 localhost.localdomain systemd[1]: Starting Zabbix Server...
-- Subject: Unit zabbix-server.service has begun start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel

-- Unit zabbix-server.service has begun starting up.
1月 07 15:21:27 localhost.localdomain systemd[1]: PID file /run/zabbix/zabbix_server.pid not readable (yet?) after start.
1月 07 15:21:27 localhost.localdomain systemd[1]: zabbix-server.service never wrote its PID file. Failing.
1月 07 15:21:27 localhost.localdomain systemd[1]: Failed to start Zabbix Server.
-- Subject: Unit zabbix-server.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
-- 
-- Unit zabbix-server.service has failed.
-- 
-- The result is failed.
1月 07 15:21:27 localhost.localdomain systemd[1]: Unit zabbix-server.service entered failed state.
1月 07 15:21:27 localhost.localdomain systemd[1]: zabbix-server.service failed.
1月 07 15:21:27 localhost.localdomain polkitd[804]: Unregistered Authentication Agent for unix-process:6797:8832061 (system bus name
lines 1907-1944/1944 (END)
Last login: Tue Jan 7 23:24:43 2020 from 10.100.81.67

查看 zabbix 日志分析：
发现日志提示权限问题：

5966:20200107:145500.376 using configuration file: /etc/zabbix/zabbix_server.conf
5966:20200107:145500.376 cannot set resource limit: [13] Permission denied
5966:20200107:145500.376 cannot disable core dump, exiting...
5976:20200107:145506.314 Starting Zabbix Server. Zabbix 4.4.4 (revision 3131fdac04

问题根源分析：

  [root@localhost logs]# getenforce
Enforcing------这时发现selinux的配置是Enforcing
[root@localhost logs]# sestatus
SELinux status:                 enabled
SELinuxfs mount:                /sys/fs/selinux
SELinux root directory:         /etc/selinux
Loaded policy name:             targeted
Current mode:                   enforcing
Mode from config file:          enforcing
Policy MLS status:              enabled
Policy deny_unknown status:     allowed
Max kernel policy version:      28
[root@localhost logs]# cd /etc/selinux
[root@localhost selinux]# ls
config  final  semanage.conf  targeted  tmp

直接把selinux 关掉如下：
[root@localhost selinux]# vi 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=disabled
SELINUXTYPE= can take one of three two values:
    targeted - Targeted processes are protected,
    minimum - Modification of targeted policy. Only selected processes are protected.
    mls - Multi Level Security protection.
SELINUXTYPE=targeted

优化修改SELINUX=disabled 
[root@localhost selinux]# vi 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=disabled
#SELINUXTYPE= can take one of three two values:
#targeted - Targeted processes are protected,
#minimum - Modification of targeted policy. Only selected #processes are protected.
#mls - Multi Level Security protection.
SELINUXTYPE=targeted

重新启动：

[root@localhost ~]# systemctl start zabbix-server.service
[root@localhost ~]# systemctl status zabbix-server.service
● zabbix-server.service - Zabbix Server
Loaded: loaded (/usr/lib/systemd/system/zabbix-server.service; disabled; vendor preset: disabled)
Active: active (running) since 二 2020-01-07 15:26:56 CST; 6s ago
Process: 1529 ExecStart=/usr/sbin/zabbix_server -c $CONFFILE (code=exited, status=0/SUCCESS)
Main PID: 1531 (zabbix_server)
CGroup: /system.slice/zabbix-server.service
└─1531 /usr/sbin/zabbix_server -c /etc/zabbix/zabbix_server.conf

1月 07 15:26:56 localhost.localdomain systemd[1]: Starting Zabbix Server...
1月 07 15:26:56 localhost.localdomain systemd[1]: zabbix-server.service: Supervising process 1531 which is not our child. ...exits.
1月 07 15:26:56 localhost.localdomain systemd[1]: Started Zabbix Server.
Hint: Some lines were ellipsized, use -l to show in full.
[root@localhost ~]#

因此，一般在安装一些开源软件，如MYSQL、POSTGRES、zabbix、openshift等，在安装前先检查下系统对应版本是否与需安装的软件兼容性、在检查下下，防火墙、安全等是否开启，如下：
1、iptables开启和关闭
2、SELinux开启和关闭
3、CentOS 6和CentOS 7 firewalld防火墙的开与关等