centos7.0版本之后相对于以前的版本更改行还是很大的，原先在6.5版本之前命令和配置文件大致都差不多，自7.0版本之后一些功能都有较大的改变，接下来会从防火墙和服务的相关配置来进行剖析。
（一）防火墙firewall的相关介绍及配置
CentOS 7中防火墙是一个非常的强大的功能，在CentOS 6.5中在iptables防火墙中进行了升级了。(he dynamic firewall daemon firewalld provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly-----官方文档)
firewall--区域zone
网络区域定义了网络连接的可信等级。这是一个 一对多的关系，这意味着一次连接可以仅仅是一个区域的一部分，而一个区域可以用于很多连接。那个区域是否可用室友firewall提供的区域按照从不信任到信任的顺序排序。
firewall 分类
Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. NetworkManager informs firewalld to which zone an interface belongs. An interface’s assigned zone can be changed by NetworkManager or via the firewall-config tool which can open the relevant NetworkManager window for you.
The zone settings in /etc/firewalld/ are a range of preset settings which can be quickly applied to a network interface. They are listed here with a brief explanation:
drop
Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible.
block
Any incoming network connections are rejected with an icmp-host-prohibited message for IPv4 and icmp6-adm-prohibited for IPv6. Only network connections initiated from within the system are possible.
public
For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.
external
For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted.
dmz
For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted.
work
For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
home
For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted.
internal
For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted.
trusted
All network connections are accepted.
It is possible to designate one of these zones to be the default zone. When interface connections are added to NetworkManager, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone.
firewall相关的配置:
1，系统配置目录：/usr/lib/firewalld
[[email protected] firewalld]# cd /usr/lib/firewalld [[email protected] firewalld]# ls icmptypes services xmlschema zones [[email protected] firewalld]# cd services/ [[email protected] services]# ls amanda-client.xml high-availability.xml ldap.xml pmproxy.xml samba.xml bacula-client.xml https.xml libvirt-tls.xml pmwebapis.xml smtp.xml bacula.xml http.xml libvirt.xml pmwebapi.xml ssh.xml dhcpv6-client.xml imaps.xml mdns.xml pop3s.xml telnet.xml dhcpv6.xml ipp-client.xml mountd.xml postgresql.xml tftp-client.xml dhcp.xml ipp.xml ms-wbt.xml proxy-dhcp.xml tftp.xml dns.xml ipsec.xml mysql.xml radius.xml transmission-client.xml freeipa-ldaps.xml iscsi-target.xml nfs.xml RH-Satellite-6.xml vdsm.xml freeipa-ldap.xml kerberos.xml ntp.xml rpc-bind.xml vnc-server.xml freeipa-replication.xml kpasswd.xml openvpn.xml rsyncd.xml wbem-https.xml ftp.xml ldaps.xml pmcd.xml samba-client.xml [[email protected] services]#
注意：目录中存放定义好的网络服务和端口参数，系统参数，不能修改。
2，用户配置目录：/etc/firewalld/
[[email protected] firewalld]# cd /etc/firewalld/ [[email protected] firewalld]# ls firewalld.conf icmptypes lockdown-whitelist.xml services zones
3,用户如何自定义添加端口，分为使用命令行添加和修改相关的配置文件。
3.1，使用命令的方式添加
[[email protected] services]# firewall-cmd --zone=public --permanent --add-port=8080/tcp success [[email protected] services]# firewall-cmd --reload
参数介绍：
1、firewall-cmd：是Linux提供的操作firewall的一个工具；
2、--permanent：表示设置为持久；
3、--add-port：标识添加的端口
4、--zone:指定某个区域
5、firewall-cmd --reload ：重启生效
3.2修改配置文件方式添加端口
[[email protected] zones]# vim /usr/lib/firewalld/zones/public.xml <?xml version="1.0" encoding="utf-8"?> <zone> <short>Public</short> <description>For use in public areas. You do not trust the other computers on networks to not harm your computer. O nly selected incoming connections are accepted.</description> <service name="ssh"/> <service name="dhcpv6-client"/> <rule family="ipv4"> <source address="127.0.0.1"/> <port protocol="tcp" port="10050-10051"/> <accept/> </rule> </zone>
firewall常用命令：
1，重启，关闭开启firewall.service服务
[[email protected] zones]# service firewalld restart Redirecting to /bin/systemctl restart firewalld.service [[email protected] zones]# service firewalld stop Redirecting to /bin/systemctl stop firewalld.service [[email protected] zones]# service firewalld start Redirecting to /bin/systemctl start firewalld.service
2，查看firewalld服务状态：
[[email protected] zones]# systemctl status firewalld ● firewalld.service - firewalld - dynamic firewall daemon Loaded: loaded (/usr/lib/systemd/system/firewalld.service; disabled; vendor preset: enabled) Active: active (running) since Wed 2017-04-19 11:10:50 CST; 43s ago Main PID: 4290 (firewalld) CGroup: /system.slice/firewalld.service └─4290 /usr/bin/python -Es /usr/sbin/firewalld --nofork --nopid Apr 19 11:10:50 iZbp1hxo8urkhrybu3wwhyZ systemd[1]: Starting firewalld - dynamic firewall daemon... Apr 19 11:10:50 iZbp1hxo8urkhrybu3wwhyZ systemd[1]: Started firewalld - dynamic firewall daemon.
3，查看firewall的状态
[[email protected] zones]# firewall-cmd --state running
4,查看防火墙firewall规则
[[email protected] ~]# firewall-cmd --list-all public (default) interfaces: sources: services: dhcpv6-client ssh ports: 10050/tcp 8080/tcp 10051/tcp masquerade: no forward-ports: icmp-blocks: rich rules:
后注：如果感觉firewall防火墙玩不好，可以关闭firewall而安装iptables,具体步骤如下
[[email protected] ~]# service firewalld stop ####停止firewalld服务 Redirecting to /bin/systemctl stop firewalld.service [[email protected] ~]# systemctl disable firewalld.service ####禁止firewalld开机启动 [[email protected] ~]# yum install iptables-services #####安装iptables Loaded plugins: fastestmirror Repodata is over 2 weeks old. Install yum-cron? Or run: yum makecache fast base | 3.6 kB 00:00:00 epel | 4.3 kB 00:00:00 extras | 3.4 kB 00:00:00 updates | 3.4 kB 00:00:00 [[email protected] ~]# vim /etc/sysconfig/iptables ########编辑iptables配置文件 [[email protected] ~]#service iptables start #开启 [[email protected] ~]#systemctl enable iptables.service #设置防火墙开机启动
备注：centos7.Xfireward防火墙基本使用：
1、firewalld的基本使用 启动： systemctl start firewalld 查看状态： systemctl status firewalld 停止： systemctl disable firewalld 禁用： systemctl stop firewalld 2.systemctl是CentOS7的服务管理工具中主要的工具，它融合之前service和chkconfig的功能于一体。 启动一个服务：systemctl start firewalld.service关闭一个服务：systemctl stop firewalld.service重启一个服务：systemctl restart firewalld.service显示一个服务的状态：systemctl status firewalld.service在开机时启用一个服务：systemctl enable firewalld.service在开机时禁用一个服务：systemctl disable firewalld.service查看服务是否开机启动：systemctl is-enabled firewalld.service查看已启动的服务列表：systemctl list-unit-files|grep enabled查看启动失败的服务列表：systemctl --failed 3.配置firewalld-cmd 查看版本： firewall-cmd --version 查看帮助： firewall-cmd --help 显示状态： firewall-cmd --state 查看所有打开的端口： firewall-cmd --zone=public --list-ports 更新防火墙规则： firewall-cmd --reload 查看区域信息: firewall-cmd --get-active-zones 查看指定接口所属区域： firewall-cmd --get-zone-of-interface=eth0 拒绝所有包：firewall-cmd --panic-on 取消拒绝状态： firewall-cmd --panic-off 查看是否拒绝： firewall-cmd --query-panic 那怎么开启一个端口呢 添加 firewall-cmd --zone=public --add-port=80/tcp --permanent （--permanent永久生效，没有此参数重启后失效） 重新载入 firewall-cmd --reload 查看 firewall-cmd --zone= public --query-port=80/tcp 删除 firewall-cmd --zone= public --remove-port=80/tcp --permanent
（二）centos 7.x添加自定义服务
Centos 系统服务脚本目录：
/usr/lib/systemd/
有系统（system）和用户（user）之分，
如需要开机没有登陆情况下就能运行的程序，存在系统服务（system）里，即：
/lib/systemd/system/
反之，用户登录后才能运行的程序，存在用户（user）里
服务以.service结尾。
这边以nginx开机运行为例
1,建立服务文件
[[email protected] system]# vim nginx.service [Unit] Description=nginx After=network.target [Service] Type=forking ExecStart=/usr/local/nginx/sbin/nginx ExecReload=/usr/local/nginx/sbin/nginx -s reload ExecStop=/usr/local/nginx/sbin/nginx -s quit PrivateTmp=true [Install] WantedBy=multi-user.target
说明：
Unit]:服务的说明
Description:描述服务
After:描述服务类别
[Service]服务运行参数的设置
Type=forking是后台运行的形式
ExecStart为服务的具体运行命令
ExecReload为重启命令
ExecStop为停止命令
PrivateTmp=True表示给服务分配独立的临时空间
注意：[Service]的启动、重启、停止命令全部要求使用绝对路径
[Install]服务安装的相关设置，可设置为多用户
2，保存该文件，并赋予754权限
[[email protected] system]# chmod 754 nginx.service [[email protected] system]# ll nginx.service -rwxr-xr-- 1 root root 258 Apr 19 14:39 nginx.service
3，设置开机自启动
[[email protected] system]# systemctl enable nginx.service [[email protected] system]# systemctl list-unit-files|grep enabled|grep nginx.service nginx.service enabled
其他相关的命令
systemctl 是系统服务管理器命令，它实际上将 service 和 chkconfig 这两个命令组合到一起。
| 任务 | 旧指令 | 新指令 |
| 使某服务自动启动 | chkconfig –level 3 httpd on | systemctl enable httpd.service |
| 使某服务不自动启动 | chkconfig –level 3 httpd off | systemctl disable httpd.service |
| 检查服务状态 | service httpd status | systemctl status httpd.service （服务详细信息） systemctl is-active httpd.service （仅显示是否 Active) |
| 显示所有已启动的服务 | chkconfig –list | systemctl list-units |grep enabled |
| 启动某服务 | service httpd start | systemctl start httpd.service |
| 停止某服务 | service httpd stop | systemctl stop httpd.service |
| 重启某服务 | service httpd restart | systemctl restart httpd.service |
启动nginx服务 systemctl start nginx.service 设置开机自启动 systemctl enable nginx.service 停止开机自启动 systemctl disable nginx.service 查看服务当前状态 systemctl status nginx.service 重新启动服务 systemctl restart nginx.service 查看所有已启动的服务 systemctl list-units --type=service 分类: 网络 列出所有服务的层级和依赖关系，可以指定某个服务 systemctl list-dependencies [服务名称]