Docker Compose Load Blancing and Scaling

Please finish Docker Compose Networking Deep Dive firstly.

In this lab, we will create a web service, try to scale this service, and add load blancer.

docker-compose.yml file, we just use two images.

$ more docker-compose.yml
web:
  image: 'jwilder/whoami'
lb:
  image: 'dockercloud/haproxy:latest'
  links:
    - web
  ports:
    - '80:80'

Start and check the service.

$ docker-compose up
$ docker-compose up -d
Creating ubuntu_web_1
Creating ubuntu_lb_1
$ docker-compose ps
    Name                  Command               State                   Ports
---------------------------------------------------------------------------------------------
ubuntu_lb_1    /sbin/tini -- dockercloud- ...   Up      1936/tcp, 443/tcp, 0.0.0.0:80->80/tcp
ubuntu_web_1   /bin/sh -c php-fpm -d vari ...   Up      80/tcp

Open the browser and check the hostname.

Scale the web service to 2 and check:

$ docker-compose scale web=3
Creating and starting ubuntu_web_2 ... done
Creating and starting ubuntu_web_3 ... done
ubuntu@aws-swarm-manager:~$ docker-compose ps
    Name                  Command               State                   Ports
---------------------------------------------------------------------------------------------
ubuntu_lb_1    /sbin/tini -- dockercloud- ...   Up      1936/tcp, 443/tcp, 0.0.0.0:80->80/tcp
ubuntu_web_1   /bin/sh -c php-fpm -d vari ...   Up      80/tcp
ubuntu_web_2   /bin/sh -c php-fpm -d vari ...   Up      80/tcp
ubuntu_web_3   /bin/sh -c php-fpm -d vari ...   Up      80/tcp