events {
    worker_connections 1024;
}

http {
    include       /etc/nginx/mime.types;
    default_type  application/octet-stream;

    # DNS Docker: risolve di nuovo l'IP di rails dopo ogni recreate container.
    resolver 127.0.0.11 valid=5s ipv6=off;

    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }

    server {
        listen 80;
        server_name _;

        client_max_body_size 20M;

        set $rails_backend rails:3000;

        location = /edge-health {
            access_log off;
            add_header Content-Type text/plain;
            return 200 "ok\n";
        }

        # Health check ops: pass-through senza pagina di cortesia.
        location = /up {
            proxy_pass http://$rails_backend;
            proxy_connect_timeout 2s;
            proxy_read_timeout 10s;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        location = /up/deep {
            proxy_pass http://$rails_backend;
            proxy_connect_timeout 2s;
            proxy_read_timeout 30s;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        location /cable {
            proxy_pass http://$rails_backend;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_read_timeout 86400;
            proxy_connect_timeout 2s;
            error_page 502 503 504 = @maintenance;
        }

        location / {
            proxy_pass http://$rails_backend;
            proxy_connect_timeout 2s;
            proxy_read_timeout 120s;
            proxy_set_header Host $host;
            proxy_set_header X-Real-IP $remote_addr;
            proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            error_page 502 503 504 = @maintenance;
        }

        location @maintenance {
            internal;
            root /usr/share/nginx/maintenance;
            try_files /index.html =503;
            add_header Retry-After 15 always;
            add_header Cache-Control "no-store" always;
        }
    }
}