Fixing 502 Bad Gateway Errors on Valet with Nginx

This error is usually caused by AJAX calls, and is due to there being too much data in the request for Nginx to process with its current settings.

1. Create ~/.config/valet/nginx/all.conf with the following:

    proxy_buffer_size 4096k;
    proxy_buffers 128 4096k;
    proxy_busy_buffers_size 4096k;
   

2. Append the following to /usr/local/etc/nginx/fastcgi_params

    fastcgi_buffer_size 4096k;
    fastcgi_buffers 128 4096k;
    fastcgi_busy_buffers_size 4096k;
   

3. Restart valet as both Nginx and PHP-FPM must be restarted for these settings to take effect.