MoriTanosuke/README.md

## README.md

      
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              README.md
            
          
    This gist is an example of a load balancing setup of tomcat, haproxy and docker.
To run the example, execute the following commands on the command line:
# start up the load balancer and one tomcat instance
docker-compose up -d
# open http://localhost and reload the page a couple of times

# now we start up another tomcat instance
docker-compose scale web=2
# reload http://localhost a couple of times again
# notice how the hostname is changing based on the tomcat instances


## docker-compose.yml
version: '2'
services:
  web:
    image: tomcat:alpine
    volumes:
      - ./index.jsp:/usr/local/tomcat/webapps/ROOT/index.jsp:ro
  lb:
    image: dockercloud/haproxy
    links:
      - web
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock
    ports:
      - 80:80

## index.jsp
<html>
<body>
This is host <strong><%= java.net.InetAddress.getLocalHost().getHostName() %></strong>.
</body>
</html>
	version: '2'
	services:
	web:
	image: tomcat:alpine
	volumes:
	- ./index.jsp:/usr/local/tomcat/webapps/ROOT/index.jsp:ro
	lb:
	image: dockercloud/haproxy
	links:
	- web
	volumes:
	- /var/run/docker.sock:/var/run/docker.sock
	ports:
	- 80:80
	<html>
	<body>
	This is host <strong><%= java.net.InetAddress.getLocalHost().getHostName() %></strong>.
	</body>
	</html>