我的问题是我有重叠的监听指令。我设法通过运行来找出重叠的指令

grep -r listen /etc/nginx/*

两个文件在同一个端口监听:

/etc/nginx/conf.d/default.conf:           listen 80;  
/etc/nginx/sites-enabled/default.conf:    listen 80;

我发现了以前从未有过的问题。

我只需要删除/etc/nginx/sites-available/default。然后就成功了。

此删除将只删除符号链接，作为备份，您可以在默认文件中找到 /etc/nginx/sites-enabled /违约

我的conf在/etc/nginx/default

[::]:80是ipv6地址。

如果你有一个nginx配置，监听端口80和端口[::]:80，就会导致这个错误。

我有以下在我的默认网站可用文件:

listen 80;
listen [::]:80 default_server;

你可以通过添加ipv6only=on到[::]:80来解决这个问题，就像这样:

listen 80;
listen [::]:80 ipv6only=on default_server;

有关更多信息，请参见:

http://forum.linode.com/viewtopic.php?t=8580

http://wiki.nginx.org/HttpCoreModule#listen

在我的例子中，罪魁祸首是一个服务器块，它包含:

        listen  127.0.0.1:80;
        listen  [::1]:80 ipv6only=on;
        server_name  localhost;

在Linux上，侦听特定IP的套接字(例如[::1]:80)与侦听同一端口但任何IP的套接字(例如[::]:80)发生冲突。通常nginx会在幕后使用一个套接字来透明地处理这个问题。然而，在listen指令上显式指定ipv6only(或某些其他选项)会迫使nginx(尝试)为它创建一个单独的套接字，从而导致Address already in use错误。

由于ipv6only=on是默认的(自1.3.4以来)，修复只是简单地从这个指令中删除该选项，并确保ipv6only不在我的配置中的其他任何地方使用。

我也遇到过类似的问题。日志如下所示

2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:443 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to [::]:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:443 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to [::]:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:443 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to [::]:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:443 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to [::]:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to 0.0.0.0:443 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: bind() to [::]:80 failed (98: Address already in use)
2018/10/31 12:54:20 [emerg] 128005#128005: still could not bind()
2018/10/31 12:54:23 [alert] 127997#127997: unlink() "/run/nginx.pid" failed (2: No such file or directory)
2018/10/31 22:40:48 [info] 36948#36948: Using 32768KiB of shared memory for push module in /etc/nginx/nginx.conf:68
2018/10/31 22:50:40 [emerg] 37638#37638: duplicate listen options for [::]:80 in /etc/nginx/sites-enabled/default:18
2018/10/31 22:51:33 [info] 37787#37787: Using 32768KiB of shared memory for push module in /etc/nginx/nginx.conf:68

最后一个[emerg]显示了[::]:80的重复监听选项，这意味着有多个nginx块文件包含[::]:80。

我的解决方案是删除[::]:80设置之一

附注:你可能有默认块文件。我的建议是将该文件作为端口80的默认服务器。并从其他块文件中删除[::]:80

我也有同样的问题，但我看到Nginx监听了80端口:

tcp        0      0 0.0.0.0:80                  0.0.0.0:*                   LISTEN      9730/nginx 

但是当我试图重新启动它时，我有错误:

    service nginx restart
Stopping nginx:                                            [FAILED]
Starting nginx: nginx: [emerg] bind() to 0.0.0.0:80 failed (98: Address already in use)
nginx: [emerg] bind() to 0.0.0.0:443 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 0.0.0.0:443 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 0.0.0.0:443 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 0.0.0.0:443 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 0.0.0.0:443 failed (98: Address already in use)
nginx: [emerg] still could not bind()

我的问题是在配置文件，我设置PID文件，似乎系统不能正确捕获它:

user nginx;
worker_processes 1;
error_log /var/log/nginx/error.log;
pid /run/nginx.pid;

当我取出它时，它工作了。