如何排查nginx服务启动情况，杀死端口，以及防火墙开放指定端口【linux与nginx排查手册】

利用NGINX搭建了视频服务，突然发现启动不了了，于是命令开始

使用以下命令查看更详细的错误信息：
*
复制代码
```
  systemctl status nginx.service
```
Warning: The unit file, source configuration file or drop-ins of nginx.service changed on disk. Run 'systemctl daemon-reload' to reload units. Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details. [root@raw /]# sudo systemctl daemon-reload [root@raw /]# systemctl status nginx.service ● nginx.service Loaded: loaded (/etc/systemd/system/nginx.service; bad; vendor preset: disabled) Active: failed (Result: exit-code) since Thu 2024-04-18 11:23:02 CST; 14s ago

4月 18 11:23:02 raw.githubusercontent.com systemd[1]: Starting nginx.service... 4月 18 11:23:02 raw.githubusercontent.com systemd[1]: nginx.service: Control process exited, code=exited status=203 4月 18 11:23:02 raw.githubusercontent.com systemd[1]: nginx.service: Failed with result 'exit-code'. 4月 18 11:23:02 raw.githubusercontent.com systemd[1]: Failed to start nginx.service. 4月 18 11:23:12 raw.githubusercontent.com systemd[1]: /etc/systemd/system/nginx.service:1: Assignment outside of section. Ignoring. 4月 18 11:23:12 raw.githubusercontent.com systemd[1]: /etc/systemd/system/nginx.service:2: Assignment outside of section. Ignoring. 4月 18 11:23:12 raw.githubusercontent.com systemd[1]: /etc/systemd/system/nginx.service:3: Assignment outside of section. Ignoring. 4月 18 11:23:16 raw.githubusercontent.com systemd[1]: /etc/systemd/system/nginx.service:1: Missing '='. [root@raw /]# sudo systemctl start nginx Job for nginx.service failed because the control process exited with error code. See "systemctl status nginx.service" and "journalctl -xe" for details. [root@raw /]# systemctl status nginx.service ● nginx.service Loaded: loaded (/etc/systemd/system/nginx.service; bad; vendor preset: disabled) Active: failed (Result: exit-code) since Thu 2024-04-18 11:23:22 CST; 7s ago Process: 41057 ExecStart=/usr/local/nginx/sbin/nginx (code=exited, status=1/FAILURE)

4月 18 11:23:21 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:8090 failed (98: Address already in use) 4月 18 11:23:21 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:82 failed (98: Address already in use) 4月 18 11:23:21 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:8090 failed (98: Address already in use) 4月 18 11:23:21 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:82 failed (98: Address already in use) 4月 18 11:23:22 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:8090 failed (98: Address already in use) 4月 18 11:23:22 raw.githubusercontent.com nginx[41057]: nginx: [emerg] bind() to 0.0.0.0:82 failed (98: Address already in use) 4月 18 11:23:22 raw.githubusercontent.com nginx[41057]: nginx: [emerg] still could not bind() 4月 18 11:23:22 raw.githubusercontent.com systemd[1]: nginx.service: Control process exited, code=exited status=1 4月 18 11:23:22 raw.githubusercontent.com systemd[1]: nginx.service: Failed with result 'exit-code'. 4月 18 11:23:22 raw.githubusercontent.com systemd[1]: Failed to start nginx.service.

然后发现是端口被占用，先杀死端口吧

问题出现在尝试启动 Nginx 时遇到端口冲突导致无法绑定到指定的端口（0.0.0.0:8090 和 0.0.0.0:82）上。可以按照以下步骤解决这个问题：

查找占用端口的进程：
- 使用以下命令查找占用端口 8090 和 82 的进程：
  复制代码
```
sudo netstat -tuln | grep ':8090\|:82'
```
停止占用端口的进程：
- 根据上一步的输出，找到占用端口的进程，并停止它们，可以使用以下命令杀死占用端口 8090 的进程（假设 PID 为 XXX）：
  复制代码
```
sudo kill XXX
```
修改 Nginx 配置文件：
- 如果需要修改 Nginx 配置文件中监听的端口，可以编辑 Nginx 配置文件（通常在 /usr/local/nginx/conf/nginx.conf）并将监听端口修改为未被占用的端口，例如 8080。
重新加载 Nginx 配置并启动服务：
- 保存修改后的配置文件，然后重新加载 Nginx 配置并尝试启动 Nginx 服务：
  复制代码
```
sudo /usr/local/nginx/sbin/nginx -s reload
```
再次检查 Nginx 服务状态：
- 使用以下命令再次检查 Nginx 服务的状态：
  复制代码
```
systemctl status nginx
```

通过找到并停止占用端口的进程，修改 Nginx 配置文件中的监听端口，然后重新加载配置并启动 Nginx 服务，应该可以解决端口冲突导致的启动问题。

然后命令重启nginx

复制代码

[root@raw conf]# sudo systemctl start nginx

[root@raw conf]# systemctl status nginx

● nginx.service

Loaded: loaded (/etc/systemd/system/nginx.service; bad; vendor preset: disabled)

Active: active (running) since Thu 2024-04-18 11:31:03 CST; 5s ago

Process: 41932 ExecStart=/usr/local/nginx/sbin/nginx (code=exited, status=0/SUCCESS)

Main PID: 41933 (nginx)

Tasks: 2 (limit: 203695)

Memory: 1.3M

CGroup: /system.slice/nginx.service

├─41933 nginx: master process /usr/local/nginx/sbin/nginx

└─41934 nginx: worker process

4月 18 11:31:03 raw.githubusercontent.com systemd $1$ : Starting nginx.service...

4月 18 11:31:03 raw.githubusercontent.com systemd $1$ : Started nginx.service.

外界还看不到视频的话，那就是防火墙拦截了，再开启端口：

要开放特定端口（例如82端口），您可以按照以下步骤在防火墙中添加规则以允许流量通过该端口：

使用 firewall-cmd 命令添加端口规则：
- 执行以下命令以永久性地开放82端口： txt
  复制代码
```
sudo firewall-cmd --zone=public --add-port=82/tcp --permanent
```
重新加载防火墙规则：
- 执行以下命令以重新加载防火墙规则，使新的端口规则生效：
  复制代码
```
sudo firewall-cmd --reload
```
验证端口是否已开放：
- 您可以运行以下命令来查看防火墙规则，确认82端口已成功开放：
  复制代码
```
sudo firewall-cmd --list-all
```

通过执行以上步骤，可以在防火墙中添加规则以允许流量通过82端口。

$root@raw conf$ # sudo firewall-cmd --zone=public --add-port=82/tcp --permanent

success

$root@raw conf$ # sudo firewall-cmd --reload

success

$root@raw conf$ # sudo firewall-cmd --list-all

public (active)

target: default

icmp-block-inversion: no

interfaces: ens192

sources:

services: cockpit dhcpv6-client ssh

ports: 82/tcp

protocols:

forward: no

masquerade: no

forward-ports:

source-ports:

icmp-blocks:

rich rules:

$root@raw conf$ #

然后成功