## The FROM instruction below builds our first layer using an official image: FROM ruby:<%= config %>-alpine
LABEL maintainer=“<%= config %> using RoRo”
# Add basic packages RUN apk add –no-cache \
build-base \ postgresql-dev \ nodejs \ yarn \ tzdata \ file
## Set APP_HOME and BUNDLE_PATH as using ENV instructions: ENV APP_HOME /usr/src/app/ ENV BUNDLE_PATH /gems
## Create both as directories to make sure they exist: RUN mkdir -p ${APP_HOME} RUN mkdir ${BUNDLE_PATH}
## Tell Docker to create volumes for our workspace and gems ## so other containers can access them.
RUN gem install bundler:2.1.4
WORKDIR ${APP_HOME}
COPY Gemfile* ./
RUN bundle –jobs 4 COPY . ${APP_HOME}