After following the steps below you should be able to browse to site1.org and site2.org in your default web browser and see the HAProxy woking. If you are not sure what a reverse proxy is and when to use it check out this post for further information.

A overlay network has to be created first using the following command:

docker network create --driver overlay --scope swarm proxy

docker stack deploy -c proxy\docker-compose.haproxy.yml proxy

docker stack deploy -c viz\docker-compose.viz.yml viz

docker stack deploy -c site1\docker-compose.web.yml site1

docker stack deploy -c site1\docker-compose.web.yml site2

Add the host site1.org and site2.org to your hosts file.

On windows 10 the hosts files is under: C:\Windows\System32\drivers\etc

On a mac the hosts file is under: /private/etc

Add the following lines.

127.0.0.1       site1.org
127.0.0.1       site2.org
127.0.0.1       viz.org

HAProxy offers a nice stats page. Open your browser and navigate to localhost:1936. It uses basic auth for seccurity. Default username and password is stats:stats

It is now possible to scale your webservice to as many containers as needed. HAProxy will take care of load balancing all of them.

docker service scale site1_app=5

or

docker service scale site2_app=3