ruby-on-rails – Docker,使用docker flag -p 3000：3000无法

我正在尝试使用带有rails的docker,在一个容器内构建一个完整的堆栈.我的结论是使用runit作为进程管理器的nginx / memcached / unicorn / rails / postgres堆栈.到目前为止,我安装了我的app,ruby和postgres.此时我正在尝试测试一切是否正常工作,然后再继续使用nginx / memcached / unicorn.
这是我的dockerfile：

FROM ubuntu:trusty

ADD . /app

# Update repos
RUN apt-get update

# General 
RUN apt-get install -y git curl software-properties-common python-software-properties ssh

# Install ruby (taken from https://gist.github.com/konklone/6662393)
RUN curl -Lk https://get.rvm.io | bash -s stable
RUN /bin/bash -l -c "rvm requirements"
RUN /bin/bash -l -c "rvm install 2.1.1"
ENV PATH /usr/local/rvm/gems/ruby-2.1.1/bin:/usr/local/rvm/rubies/ruby-2.1.1/bin:$PATH
RUN gem install bundler --no-ri --no-rdoc

# Install nodejs (rails js runtime)
RUN apt-get install -y nodejs

# Install postgresql (adapted from https://wiki.postgresql.org/wiki/Apt)
RUN echo "deb http://apt.postgresql.org/pub/repos/apt/ $(lsb_release -sc)-pgdg main"
RUN curl https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
RUN apt-get update
RUN apt-get install -y postgresql-9.3 postgresql-client-9.3 postgresql-contrib-9.3

# Setup postgresql
RUN mkdir /pgsql && chown postgres /pgsql
USER postgres
ENV PATH $PATH:/usr/lib/postgresql/9.3/bin/
RUN initdb -E UTF8 -D /pgsql/data
USER root

# Needed for pg gem (from https://stackoverflow.com/a/20754173)
RUN apt-get install -y libpq-dev

然后我使用以下命令创建一个容器

docker run -it -p 3000:3000 *dockerfile_image* /bin/bash -l

在该容器内部,我将postgresql设置为后台作业并运行rails s

$sudo -u postgres /usr/lib/postgresql/9.3/bin/postgres -D /pgsql/data
^z
$bg
$sudo -u postgres /usr/bin/psql -c "create role *appname* login createdb"
$cd /app
$bundle && rake db:create db:migrate
$rails s
=> Booting WEBrick
=> Rails 4.1.0 application starting in development on http://0.0.0.0:3000
=> Run `rails server -h` for more startup options
=> Notice: server is listening on all interfaces (0.0.0.0). Consider using 127.0.0.1 (--binding option)
=> Ctrl-C to shutdown server
....

但正如标题所述,我无法从localhost：3000连接.
我也试过了

>尝试从0.0.0.0:3000连接
>离开-p 3000：3000并尝试从container_ip：3000连接
>在dockerfile中EXPOSE 3000,使用docker ps查找映射端口并尝试localhost：mapped_port

另外我不知道它是否重要,但我在OSX上使用boot2docker.