dockercloud haproxy with more than one service on different ports - docker

Question

Is it possible to configure dockercloud/haproxy with more than one backend service but listening on a different port? I'm trying to get a docker-compose config working with nginx on port 80 for a web frontend, and then a container on 8080 running a Spring Boot app.
It appears by default haproxy is seeing the linked containers for web and addressbook (see .yml file below), but by default they are both being exposed on port 80 by happroxy, and so the Spring Boot container never receives traffic on 8080.
Is this config possible, or do I need to run 2 different haproxy containers too, one for web, and one for the REST backend service?
Here's my docker-compose.yml so far:
version: '2'
#build:
# context: ./haproxy
# image: haproxy
# dockerfile: Dockerfile
services:
mongodata:
image: mongo:3.2
volumes:
- /data/db
entrypoint: /bin/bash
mongo:
image: mongo:3.2
depends_on:
- mongodata
volumes_from:
- mongodata
ports:
#only specify internal port, not external, so we can scale with docker-compose scale
- "27017"
addressbook:
image: addressbook
depends_on:
- mongo
environment:
- MONGODB_DB_NAME=addressbook
ports:
- "8080"
links:
- mongo
web:
image: docker-web-angularjs
ports:
- "80"
lb:
image: dockercloud/haproxy
#TODO: need to add an haproxy.cfg to configure for addressbook instances exposed behind 8080?
#or can be configured via container properties?
#image: haproxy
depends_on:
- addressbook
environment:
- STATS_PORT=1936
- STATS_AUTH="admin:password"
links:
- addressbook
- web
volumes:
- /var/run/docker.sock:/var/run/docker.sock
ports:
- 80:80
- 8080:8080
- 1936:1936

Answer 1

To me, it's easier to use Traefik to achieve the goal.
addressbook:
image: addressbook
depends_on:
- mongo
environment:
- MONGODB_DB_NAME=addressbook
labels:
- "traefik.backend=spring_boot"
- "traefik.protocol=http"
- "traefik.port=8080"
- "traefik.frontend.entryPoints=http_8080"
ports:
- "8080"
links:
- mongo
web:
image: docker-web-angularjs
labels:
- "traefik.backend=nginx"
- "traefik.protocol=http"
- "traefik.port=80"
- "traefik.frontend.entryPoints=http_80"
ports:
- "80"
lb:
image: traefik
command: "--web --web.address=8081 --docker --docker.domain=docker.localhost \
--logLevel=DEBUG \
--entryPoints='Name:http_80 Address::80' \
--entryPoints='Name:http_8080 Address::8080'"
ports:
- 80:80
- 8080:8080
- 8081:8081
volumes:
- /var/run/docker.sock:/var/run/docker.sock
- /dev/null:/traefik.toml

Answer 2

You can expose the two services using two different paths, both on the same port of the haproxy container. You can do this using the environment variable VIRTUAL_HOST for the addressbook and web containers:
addressbook:
image: addressbook
depends_on:
- mongo
environment:
- MONGODB_DB_NAME=addressbook
- VIRTUALHOST="/addressbook/*"
ports:
- "8080"
links:
- mongo
web:
image: docker-web-angularjs
environment:
- VIRTUALHOST="/web/*"
ports:
- "80"
Unfortunately, haproxy doesn't remove the web or addressbook path by default, so you need to update the two apps in order to manage a "base path".