Using the following project really/nginx-modsecurity

Docker container providing nginx with [modsecurity] (https://www.modsecurity.org), lua and certbot for Let's Encrypt SSL certificates

The readme leaves a few things out

sudo mkdir -p /data/nginx/conf.d/
sudo nano /data/nginx/conf.d/webex.mbcurtis.com.conf
    upstream dev.mbcurtis.com {
        server 1.1.1.1;
    }

    server {
        listen       80;

        server_name  dev.mbcurtis.com;
        modsecurity on;

        location / {
            proxy_pass http://dev.mbcurtis.com/;
            proxy_next_upstream error timeout invalid_header http_500 http_502 http_503 http_504;
            proxy_redirect off;
            proxy_buffering off;
            proxy_force_ranges on;
            proxy_set_header        Host            $host;
            proxy_set_header        X-Real-IP       $remote_addr;
            proxy_set_header        X-Forwarded-For $proxy_add_x_forwarded_for;

        }

}

then start the docker

docker run --name nginx-modsecurity \
  --restart=always \
  --net=host \
  -v /data/nginx/conf.d:/etc/nginx/conf.d:rw \
  -v /data/letsencrypt:/etc/letsencrypt:rw \
  -p 80:80 -p 443:443 -d \
  really/nginx-modsecurity

after which you can run certbot which will add the SSL config to your site file

docker exec -it nginx-modsecurity certbot --no-redirect --nginx -d example.com