centOS7访问nginx失败解决-.0:80 failed (98: Address already in use)解决

凤问题描述：

[root@itheima local]# cd nginx/sbin/
[root@itheima sbin]# ./nginx
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)

前提：已经配置好静态IP

以防万一，先安装好iptables服务（不管你装没装，先执行，免得后面添乱）

[root@localhost ~]# yum install iptables-services

[root@localhost ~]# systemctl mask firewalld.service

[root@localhost ~]# systemctl enable iptables.service

[root@localhost ~]# systemctl enable ip6tables.service

进入iptables配置80端口，因为nginx默认是由80端口访问

[root@localhost ~]# vim /etc/sysconfig/iptables

这是配置信息：

# Generated by iptables-save v1.4.21 on Fri May 12 21:28:29 2017
*filter
:INPUT ACCEPT [0:0]
:FORWARD ACCEPT [0:0]
:OUTPUT ACCEPT [6:696]
-A INPUT -m state --state RELATED,ESTABLISHED -j ACCEPT
-A INPUT -p icmp -j ACCEPT
-A INPUT -i lo -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 22 -j ACCEPT
-A INPUT -p tcp -m state --state NEW -m tcp --dport 21 -j ACCEPT（我给vsftpd配置的端口）
-A INPUT -p tcp -m state --state NEW -m tcp --dport 80 -j ACCEPT（给nginx配置的端口，原样输入就行了）
-A INPUT -p tcp -m state --state NEW -m tcp --dport 30000:30999 -j ACCEPT
-A INPUT -j REJECT --reject-with icmp-host-prohibited
-A FORWARD -j REJECT --reject-with icmp-host-prohibited
COMMIT
# Completed on Fri May 12 21:28:29 2017

然后:wq，保存退出就行了

重启iptables，配置才生效

[root@localhost ~]# systemctl restart iptables.service

开启防火墙，不管你开没有，再开一遍：

[root@localhost ~]# systemctl start firewalld

开启http访问

[root@localhost ~]# firewall-cmd --permanent --add-service=http

加入80端口

[root@localhost ~]# firewall-cmd --permanent --zone=trusted --add-port=80/tcp

启动nginx！！！！（重点来了！！！）

centOS7的nginx启动与其他的有区别！！！注意：我是装的nginx1.80，在centOS6.X系列中，是通过

cd /usr/local/nginx/sbin/

./nginx 

这两条命令启动的。

在Ubuntu中是通过/etc/nginx.....,你会发现你的centOS7里面，etc下面根本就没有nginx这个folder！

在centOS7中你会发现这行不通，我们应该这么启动：

[root@localhost ~]# /usr/local/nginx/sbin/nginx

如果发现：

nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] still could not bind()

说明80端口被占用，杀掉这个进程：

[root@localhost ~]# killall -9 nginx

再次启动nginx：

[root@localhost ~]# /usr/local/nginx/sbin/nginx

查看是否启动：

[root@localhost ~]# ps aux|grep nginx

输出：

root       7110  0.0  0.0  24348   752 ?        Ss   22:32   0:00 nginx: master process /usr/local/nginx/sbin/nginx
nobody     7111  0.0  0.0  26860  1508 ?        S    22:32   0:00 nginx: worker process
root       7114  0.0  0.0 112664   968 pts/0    S+   22:33   0:00 grep --color=auto nginx

启动成功！

访问nginx

在浏览器地址栏输入你的Linux虚拟机的静态ip，会跳转到nginx的欢迎页面。