Docker rails migrations - ruby-on-rails

Question

I'm trying to get running my rails application with docker and fig, it counts with a redis server, mongodb, postgres, and nginx as well,
Here is how my fig.yml looks like:
pg:
image: docker-index.my.com/postgres
ports:
- 5432
redis:
image: docker-index.my.com/redis
ports:
- 6379
mongodb:
image: docker-index.my.com/mongodb
ports:
- 27017
app:
build: .
command: bundle exec rails s
volumes:
- .:/beesor
ports:
- 3000:3000
links:
- pg
- redis
- mongodb
environment:
RAILS_ENV: production
Everything works ok till the moment of starting app, as rails initializers hooks on server starts then I got errors regarding the database connection, the database does not exists! of course because it was not created on the Dockerfile (see below)
Dockerfile contents:
# DOCKER-VERSION 0.10.0
FROM docker-index.my.com/ruby:1.9.3
MAINTAINER my.com
RUN apt-get update -qq && apt-get install -y git-core xvfb curl nodejs libqt4-dev libgtk2.0-0 libgtkmm-3.0-1 libnotify4 sqlite3 libsqlite3-dev graphicsmagick imagemagick subversion libpq-dev libxml2-dev libxslt-dev git build-essential
RUN mkdir /my_app
WORKDIR /my_app
RUN gem install bundler
ADD Gemfile /my_app/Gemfile
ADD Gemfile.lock /my_app/Gemfile.lock
RUN bundle install
RUN bundle pack --all
ADD . /my_app
I don't see a place where I can put the rake db:create db:migrate db:seed commands!, if I put them at the end of the Dockerfile then when fig tries to build app it complains about the database server does not exits, (in the time that fig builds app container the other containers are not started), and I could not fix this changing the order on the fig.yml,
I'm facing egg-chicken problem here, who can I get this working?
I'm sure that all the links work perfectly so the problem is more about orchestration of scripts.

Answer 1

Found the solution!:
I created a rake task to wrap what I need, it runs migrations, seeds, and starts the rails server, so the fix is to change the command on fig by this one:
command: rake my_app:setup