在连接到上游时，connect()失败(111: 连接被拒绝)

I don't think that solution would work anyways because you will see some error message in your error log file.

The solution was a lot easier than what I thought.

simply, open the following path to your php5-fpm

sudo nano /etc/php5/fpm/pool.d/www.conf

or if you're the admin 'root'

nano /etc/php5/fpm/pool.d/www.conf

Then find this line and uncomment it:

listen.allowed_clients = 127.0.0.1

This solution will make you be able to use listen = 127.0.0.1:9000 in your vhost blocks

like this: fastcgi_pass 127.0.0.1:9000;

after you make the modifications, all you need is to restart or reload both Nginx and Php5-fpm

Php5-fpm

sudo service php5-fpm restart

or

sudo service php5-fpm reload

Nginx

sudo service nginx restart

or

sudo service nginx reload

From the comments:

Also comment

;listen = /var/run/php5-fpm.sock

and add

listen = 9000

I had the same problem when I wrote two upstreams in NGINX conf

upstream php_upstream {
server unix:/var/run/php/my.site.sock;
server 127.0.0.1:9000;
}


...


fastcgi_pass php_upstream;

but in /etc/php/7.3/fpm/pool.d/www.conf I listened the socket only

listen = /var/run/php/my.site.sock

So I need just socket, no any 127.0.0.1:9000, and I just removed IP+port upstream

upstream php_upstream {
server unix:/var/run/php/my.site.sock;
}

This could be rewritten without an upstream

fastcgi_pass unix:/var/run/php/my.site.sock;

This may be useful for someone:

If you have multiple versions of PHP installed e.g 8.0 and 7.4 on your mac, and you have tried several options and still gets a 502 Gateway error, trying check how your valet connects with your PHP version and Nginx.

from terminal run valet use php@7.4 if that's the version you use. The current version will be unlinked and the new version linked then Nginx and php@7.4 will be restarted.

I faced the same issue in Centos 8. In this file /etc/nginx/default.d/php.conf I just replaced the below line, and it works perfectly.

#orignal line
fastcgi_pass 127.0.0.1:9000;


#replaced with
fastcgi_pass unix:/run/php-fpm/www.sock;