Dockerfile for installing ruby using rbenv

Dockerfile

# DOCKER-VERSION 0.4.8

# am facing issue
# https://github.com/dotcloud/docker/issues/1123

FROM ubuntu:12.04
 
MAINTAINER Deepak Kannan "deepak@codemancers.com"

RUN apt-get -y install python-software-properties
RUN apt-get -y update

# install essentials
RUN apt-get -y install build-essential
RUN apt-get install -y -q git

RUN add-apt-repository -y ppa:chris-lea/nginx-devel
RUN apt-get install -y -q nginx-full

# Install rbenv
RUN git clone https://github.com/sstephenson/rbenv.git /usr/local/rbenv
RUN echo '# rbenv setup' > /etc/profile.d/rbenv.sh
RUN echo 'export RBENV_ROOT=/usr/local/rbenv' >> /etc/profile.d/rbenv.sh
RUN echo 'export PATH="$RBENV_ROOT/bin:$PATH"' >> /etc/profile.d/rbenv.sh
RUN echo 'eval "$(rbenv init -)"' >> /etc/profile.d/rbenv.sh
RUN chmod +x /etc/profile.d/rbenv.sh

# install ruby-build
RUN mkdir /usr/local/rbenv/plugins
RUN git clone https://github.com/sstephenson/ruby-build.git /usr/local/rbenv/plugins/ruby-build

ENV RBENV_ROOT /usr/local/rbenv

ENV PATH "$RBENV_ROOT/bin:$RBENV_ROOT/shims:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
# does not work. PATH is set to
# $RBENV_ROOT/shims:$RBENV_ROOT/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin

# install ruby2
RUN rbenv install 2.0.0-p247

PATH is not set properly
can set PATH as
ENV PATH /usr/local/rbenv/shims:/usr/local/rbenv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
but that is not elegant

@deepak Instead of jamming the environment on the fly don't you think you could do:

RUN bash -c 'rbenv install 2.0.0-p247'

I've always been a bit confused about the environment that Dockerfile commands are run in (I really should spend a few hours figuring this out), but my workaround has always been to source whatever scripts set your environment variables in your login shell at the start of any command that requires shell magic; RUN . ~/.bashrc && rbenv install 2.0.0-p247 for example. I was never able to get RUN /bin/bash -c 'rbenv install 2.0.0-p247' to work, but like I said, I'm a bit unsure about what is happening behind the scenes.

@parkerault I have a docker image for this, but its basically bash -l -c 'rbenv' which starts a login shell and sources the profile. Or you could just fork my docker image: johnbellone/rbenv

Don't put the quotes around the path string. Leaving them off set the path correctly for me and evaluated the $RBENV_ROOT variable. Then the RUN rbenv install 2.0.0-p247 works just fine. I'm running docker 1.2, with a Ubuntu 14.04 image.

If you only need one Ruby version, use the official Ruby images: https://hub.docker.com/_/ruby