AWS EC2实例重启后Nginx服务无法启动求助

我在AWS EC2上运行Laravel应用，之前遇到upload_max_filesize限制问题，想从默认2M改成6M。根据php_info()显示当前使用的php.ini是/etc/php/8.1/fpm/php.ini，修改该文件后重启Nginx，问题没解决。在/etc目录执行grep -r "upload_max_filesize" .发现另外两个文件/etc/php/8.1/apache2/php.ini和/etc/php/8.1/cli/php.ini也有这个参数，于是更新这两个文件后再次重启Nginx。虽然在php artisan tinker里用ini_get()能获取到更新后的值，但应用的php_info()还是显示2M，于是我重启了服务器。

重启后网站无法连接，提示：

无法访问此网站
silkweb.ca 拒绝连接

检查Nginx状态发现服务未运行，但配置测试正常：

ubuntu@ip-172-31-4-36:~$ sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

ubuntu@ip-172-31-4-36:~$ sudo systemctl status nginx
× nginx.service - A high performance web server and a reverse proxy server
 Loaded: loaded (/lib/systemd/system/nginx.service; enabled; vendor preset: enabled)
 Active: failed (Result: exit-code) since Mon 2023-05-01 17:41:17 UTC; 24min ago
   Docs: man:nginx(8)
    CPU: 63ms

May 01 17:41:15 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Unknown error)
May 01 17:41:15 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to [::]:80 failed (98: Unknown error)
May 01 17:41:16 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Unknown error)
May 01 17:41:16 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to [::]:80 failed (98: Unknown error)
May 01 17:41:16 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Unknown error)
May 01 17:41:16 ip-172-31-4-36 nginx[522]: nginx: [emerg] bind() to [::]:80 failed (98: Unknown error)
May 01 17:41:17 ip-172-31-4-36 nginx[522]: nginx: [emerg] still could not bind()
May 01 17:41:17 ip-172-31-4-36 systemd[1]: nginx.service: Control process exited, code=exited, status=1/FAILURE
May 01 17:41:17 ip-172-31-4-36 systemd[1]: nginx.service: Failed with result 'exit-code'.
May 01 17:41:17 ip-172-31-4-36 systemd[1]: Failed to start A high performance web server and a reverse proxy server.
ubuntu@ip-172-31-4-36:~$ 

请问Nginx无法启动的原因是什么？（修改upload_max_filesize并重启前一切正常，已多次重启服务器问题依旧。）

原因分析与解决步骤 #

错误日志里的bind() to 0.0.0.0:80 failed (98: Unknown error)本质是端口80被其他进程占用，导致Nginx无法绑定该端口启动。结合你修改php配置后重启服务器的操作，大概率是你误启动了Apache服务——因为你修改了/etc/php/8.1/apache2/php.ini，重启服务器后Apache可能被自动启用，抢占了80端口。

解决步骤：

• 先确认哪个进程占用了80端口，执行命令：

  sudo lsof -i :80
  # 或者用netstat
  sudo netstat -tulpn | grep :80
  

• 如果确实是Apache（进程名通常是apache2）占用端口，停止并禁用Apache服务：

  sudo systemctl stop apache2
  sudo systemctl disable apache2
  

• 重新启动Nginx：

  sudo systemctl start nginx
  

• 回到最初的upload_max_filesize问题：你只需要修改/etc/php/8.1/fpm/php.ini即可，因为Laravel搭配Nginx用的是PHP-FPM，apache2和cli的php.ini不影响Web应用。修改后需要重启的是PHP-FPM服务，不是Nginx：

  sudo systemctl restart php8.1-fpm
  

内容的提问来源于stack exchange，提问作者user761100