Update Dockerfile for production

Dockerfile

@@ -1,38 +1,37 @@
-FROM       ruby:2.2
+FROM ruby:2.4.9
 
 ENV RAILS_ENV production
 
 # Add 'web' user which will run the application
 RUN adduser web --home /home/web --shell /bin/bash --disabled-password --gecos ""
 
-RUN apt-get update && apt-get -y upgrade
-RUN apt-get -y install mysql-client libmysqlclient-dev memcached nodejs
-RUN service memcached start
+RUN apt-get update && apt-get -y upgrade \
+    && apt-get -y install \
+        libmariadb-dev libmariadb-dev-compat \
+        libssl-dev  \
+        zlib1g-dev libreadline-dev libyaml-dev  \
+        libxslt1-dev libxml2-dev \
+        imagemagick libmagickwand-dev \
+        nodejs \
+        firefox-esr
 
 # Separate Gemfile ADD so that `bundle install` can be cached more effectively
+ADD Gemfile Gemfile.lock /var/www/
 
-ADD Gemfile      /var/www/
-ADD Gemfile.lock /var/www/
-RUN chown -R web:web /var/www &&\
-  mkdir -p /var/bundle &&\
-  chown -R web:web /var/bundle
-
-RUN su -c "bundle config github.https true; cd /var/www && bundle install --path /var/bundle --jobs 4" -s /bin/bash -l web
-
-# Add application source
-ADD . /var/www
-RUN chown -R web:web /var/www
+RUN gem install bundler && \
+    mkdir -p /var/bundle && chown -R web:web /var/bundle && chown -R web:web /var/www
 
 WORKDIR /var/www
 USER web
 
-RUN mkdir -p /var/www/log && touch /var/www/log/${RAILS_ENV}.log
-RUN bundle config github.https true; cd /var/www && bundle install --path /var/bundle --jobs 4
-RUN bundle exec rake assets:precompile
-
-# This is a temporary solution to fix assets issue
+RUN bundle config github.https true && \
+    bundle config set path '/var/bundle' && \
+    bundle install --jobs 8 && \
+    bundle exec rake assets:precompile
 
 USER root
+
+# Temporary fix for assets
 RUN mv /var/www/public/assets /home/web/assets
 
 CMD ["/var/www/script/entry.sh"]