nginx.conf

worker_processes auto;

events {
    worker_connections 1024;
}

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

    upstream app_cluster {
        least_conn;
        server app1:8080;
        server app2:8080;
        server app3:8080;
    }

    server {
        listen 80;

        add_header Access-Control-Allow-Origin * always;
        add_header Access-Control-Allow-Methods "GET, POST, PUT, DELETE, OPTIONS" always;
        add_header Access-Control-Allow-Headers "*" always;

        if ($request_method = OPTIONS) {
            return 204;
        }

        location /swagger-ui/ {
            alias /usr/share/nginx/html/swagger-ui/;
            try_files $uri $uri/ /swagger-ui/index.html;
        }

        location /openapi.yml {
            alias /usr/share/nginx/html/openapi.yml;
        }

        location /v3/api-docs {
            proxy_pass http://app_cluster$request_uri;
            proxy_set_header Host $host;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        location /swagger-resources/ {
            proxy_pass http://app_cluster$request_uri;
            proxy_set_header Host $host;
            proxy_set_header X-Forwarded-Proto $scheme;
        }

        location / {
            proxy_pass http://app_cluster;
            proxy_http_version 1.1;

            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_buffering on;
            proxy_buffers 8 16k;
            proxy_buffer_size 16k;

            proxy_connect_timeout 5s;
            proxy_send_timeout 30s;
            proxy_read_timeout 30s;
        }
    }
}