Unicorn+RailsアプリをDockerコンテナで起動する ref: http://qiita.com/yss44@github/items/5d6834348f53910e63d2

Dockerfile

# DOCKER-RAILS-UNICORN
#
# VERSION       1

FROM yoshiso/rails_base

MAINTAINER yoshiso


ADD supervisor/supervisord.conf /etc/supervisord.conf


#######################################   Rails  #############################################

ENV PATH /usr/local/rbenv/bin:$PATH
ENV RAILS_ENV production

# Git pull latest Rails App
RUN mkdir /var/www; cd /var/www;
RUN git clone https://github.com/yss44/unicorn_sample.git /var/www/app;

# Resolve dependencies
RUN yum -y install sqlite-devel
RUN source /etc/profile.d/rbenv.sh;gem install sqlite3 -v '1.3.8' # Have to be installed
RUN source /etc/profile.d/rbenv.sh;cd /var/www/app;bundle install -j4;

# Setup rails(db:migrate,assets precompile)
RUN source /etc/profile.d/rbenv.sh;source /etc/profile.d/nvm.sh;cd /var/www/app;RAILS_ENV=production bundle exec rake deploy:prepare;

# Add execution file used by supervisor
ADD rails/start.sh rails_start.sh
RUN chmod +x rails_start.sh

###################################### Docker config #########################################

# Environment valiables
ENV WEB_CONCURRENCY 4
ENV RAILS_ENV production

# expose for sshd,rails

EXPOSE 2222 3000

CMD ["/usr/bin/supervisord"]

install.sh

#!/bin/bash
#Install Ruby by rubyenv

if [ ! -d /usr/local/rbenv ];then
    cd /usr/local
    git clone git://github.com/sstephenson/rbenv.git rbenv
    mkdir rbenv/shims rbenv/versions rbenv/plugins
    git clone git://github.com/sstephenson/ruby-build.git /usr/local/rbenv/plugins/ruby-build

    # Setup rbenv for all user
    echo 'export RBENV_ROOT="/usr/local/rbenv"' >> /etc/profile.d/rbenv.sh
    echo 'PATH=/usr/local/rbenv/bin:$PATH' >> /etc/profile.d/rbenv.sh
    echo 'eval "$(rbenv init -)"' >> /etc/profile.d/rbenv.sh
    source /etc/profile.d/rbenv.sh

    # Install ruby
    rbenv install 2.0.0-p353
    rbenv rehash
    rbenv global 2.0.0-p353  # default ruby version

    #rbenv(add user to rbenv group if you want to use rbenv)
    useradd rbenv
    chown -R rbenv:rbenv rbenv
    chmod -R 775 rbenv

    # install withou ri,rdoc
    echo 'install: --no-ri --no-rdoc' >> /etc/.gemrc
    echo 'update: --no-ri --no-rdoc' >> /etc/.gemrc
    echo 'install: --no-ri --no-rdoc' >> /.gemrc
    echo 'update: --no-ri --no-rdoc' >> /.gemrc

    # install bundler
    gem install bundler
fi

#Install Node.js for Rails javascript runtime

if [ ! -d /usr/local/nvm ];then
    # install nvm
    git clone https://github.com/creationix/nvm.git /usr/local/nvm
    source /usr/local/nvm/nvm.sh

    # nvm(add user to nvm group if you want to use nvm)
    useradd nvm
    chown -R nvm:nvm /usr/local/nvm
    chmod -R 755 /usr/local/nvm
    nvm install 0.10.24

    # Setup rbenv for all user
    echo 'source /usr/local/nvm/nvm.sh' >> /etc/profile.d/nvm.sh
    echo 'nvm use v0.10.24' >> /etc/profile.d/nvm.sh
fi

start.sh

#!/bin/bash

source /etc/profile.d/nvm.sh;
cd /var/www/app;
/usr/local/rbenv/shims/bundle exec unicorn_rails -c /var/www/app/config/unicorn.rb -E production

supervisord.conf

[supervisord]
nodaemon=true

[program:sshd]
command=/usr/sbin/sshd -D

[program:rails_app]
command=/rails_start.sh