Docker Demo

A sample Python Web application is used to illustrate the usage of Docker.

Provides three REST API endpoints:

• /, API information
• /reset, reset the inventory to 500,000
• /reserve, reduce the inventory by 1 and return the new inventory

Instructions:

• use docker-compose build to build application images

Development

• use docker-compose up to start containers

Deployment

Create a consul machine:

$ docker-machine create \
  -d virtualbox \
  consul

Run consul-server on consul machine:

$ eval $(docker-machine env consul)
$ docker run -d \
  -p $(docker-machine ip consul):8500:8500 \
  -h consul \
  --restart always \
  gliderlabs/consul-server -bootstrap

Create Swarm master machine

$ docker-machine create \
  -d virtualbox \
  --swarm \
  --swarm-master \
  --swarm-discovery="consul://$(docker-machine ip consul):8500" \
  --engine-opt="cluster-store=consul://$(docker-machine ip consul):8500" \
  --engine-opt="cluster-advertise=eth1:2376" \
  master

Create a slave machine:

$ docker-machine create \
  -d virtualbox \
  --swarm \
  --swarm-discovery="consul://$(docker-machine ip consul):8500" \
  --engine-opt="cluster-store=consul://$(docker-machine ip consul):8500" \
  --engine-opt="cluster-advertise=eth1:2376" \
  slave

Run registrator on master and slave

eval $(docker-machine env master)

docker run -d \
  --name=registrator \
  -h $(docker-machine ip master) \
  --volume=/var/run/docker.sock:/tmp/docker.sock \
  gliderlabs/registrator:v6 \
  consul://$(docker-machine ip consul):8500

eval $(docker-machine env slave)

docker run -d \
  --name=registrator \
  -h $(docker-machine ip slave) \
  --volume=/var/run/docker.sock:/tmp/docker.sock \
  gliderlabs/registrator:v6 \
  consul://$(docker-machine ip consul):8500

Then we are ready to connect to Swarm eval $(docker-machine env -swarm master).

• run export CONSUL_IP=$(docker-machine ip consul)
• use docker-compose -f docker-compose-production.yml up -d to start containers.
• use docker-compose -f docker-compose-production.yml scale app=2 to start more app containers.
• use docker-compose -f docker-compose-production.yml exec lb cat /etc/nginx/conf.d/default.conf to check the generated nginx config.