Dockerfile of Ubuntu 16.04 + Ruby 2.3 + PostgreSQL 10

Dockerfile

FROM ubuntu:16.04

# Install required libraries
RUN apt-get update &&\
    apt-get upgrade -y &&\
    apt-get install -y --no-install-recommends \
    build-essential python-software-properties wget autoconf git-core curl \
    zlib1g-dev libssl-dev libreadline-dev libyaml-dev libxml2-dev libxslt1-dev \
    libcurl4-openssl-dev libffi-dev

# Install Ruby
ENV RUBY_MAJOR="2.3" \
    RUBY_VERSION="2.3.6" \
    RUBY_DOWNLOAD_SHA256="8322513279f9edfa612d445bc111a87894fac1128eaa539301cebfc0dd51571e" \
    RUBYGEMS_VERSION="2.7.3" \
    BUNDLER_VERSION="1.16.0" \
    GEM_HOME="/usr/local/bundle"

ENV BUNDLE_PATH="$GEM_HOME" \
    BUNDLE_BIN="$GEM_HOME/bin" \
    BUNDLE_SILENCE_ROOT_WARNING=1 \
    BUNDLE_APP_CONFIG="$GEM_HOME"

RUN mkdir -p /usr/local/etc \
    && echo "gem: --no-document" > /usr/local/etc/gemrc \
    && apt-get install -y --no-install-recommends bison libgdbm-dev ruby \
    && wget "https://cache.ruby-lang.org/pub/ruby/$RUBY_MAJOR/ruby-$RUBY_VERSION.tar.gz" -O /tmp/ruby.tar.gz \
    && echo "$RUBY_DOWNLOAD_SHA256 /tmp/ruby.tar.gz" | sha256sum -c - \
    && mkdir -p /usr/src/ruby \
    && tar -xzf /tmp/ruby.tar.gz -C /usr/src/ruby --strip-components=1 \
    && cd /usr/src/ruby \
    && { \
        echo '#define ENABLE_PATH_CHECK 0'; \
        echo; \
        cat file.c; \
    } > file.c.new \
    && mv file.c.new file.c \
    && autoconf \
    && ./configure --disable-install-doc \
    && make -j"$(nproc)" \
    && make install \
    && apt-get purge -y --auto-remove bison libgdbm-dev ruby \
    && cd / \
    && rm -r /usr/src/ruby \
    && gem update --system "$RUBYGEMS_VERSION" \
    && gem install bundler --version "$BUNDLER_VERSION" \
    && mkdir -p "$GEM_HOME" "$BUNDLE_BIN" \
    && chmod 777 "$GEM_HOME" "$BUNDLE_BIN"

# Install ImageMagick
RUN apt-get install -y imagemagick

# Install PostgreSQL v10
# Note: Ubuntu-16.04 main repository provides only postgresql-9.5
RUN echo "deb http://apt.postgresql.org/pub/repos/apt/ xenial-pgdg main" > /etc/apt/sources.list.d/pgdg.list
RUN wget --quiet -O - https://www.postgresql.org/media/keys/ACCC4CF8.asc | apt-key add -
RUN apt-get update
RUN apt-get install -y libpq-dev postgresql-10

# Clean
RUN rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* &&\
    apt-get clean

# Run the rest of the commands as the `postgres` user
USER postgres

# Create a PostgreSQL role named `docker` with `docker` as the password
# and then create a database `docker` owned by the ``docker` role.
RUN /etc/init.d/postgresql start &&\
    psql --command "CREATE USER docker WITH SUPERUSER PASSWORD 'docker_password';" &&\
    createdb -O docker docker

CMD [ "irb" ]