Improve Docker setup (PR #497)

Dockerfile

@@ -1,45 +1,58 @@
 FROM ruby:2.3
 
-RUN apt-get update && \
-    apt-get install --no-install-recommends -y cron && \
-    rm -rf /var/lib/apt/lists/* && \
-    apt-get clean
+RUN supercronicUrl=https://github.com/aptible/supercronic/releases/download/v0.1.3/supercronic-linux-amd64 && \
+    supercronicBin=/usr/local/bin/supercronic && \
+    supercronicSha1sum=96960ba3207756bb01e6892c978264e5362e117e && \
+    curl -fsSL -o "$supercronicBin" "$supercronicUrl" && \
+    echo "$supercronicSha1sum  $supercronicBin" | sha1sum -c - && \
+    chmod +x "$supercronicBin"
 
-ENV RAILS_ENV=production \
+ENV PORT=3000 \
+    SMTP_SERVER_PORT=2525 \
+    RAILS_ENV=production \
+    RAILS_LOG_TO_STDOUT=true \
     RAILS_SERVE_STATIC_FILES=true
 
 WORKDIR /usr/src/app
-COPY . ./
-RUN echo $SOURCE_COMMIT > REVISION
 
+COPY . ./
+
+# install dependencies and generate crontab
 RUN buildDeps='libmagic-dev' && \
     apt-get update && \
     apt-get install --no-install-recommends -y $buildDeps && \
-    rm -rf /var/lib/apt/lists/* && \
-    bundle install --deployment --without development test && \
+    echo 'gem: --no-document' >> ~/.gemrc && \
+    bundle config build.nokogiri "--use-system-libraries" && \
+    bundle install --deployment --without development test -j 4 && \
     apt-get purge -y --auto-remove $buildDeps && \
-    echo "Foodsoft::Application.config.secret_token = ENV['SECRET_KEY_BASE']" > config/initializers/secret_token.rb && \
-    mkdir -p log && \
-    ln -sfn /dev/stdout log/production.log && \
-    bundle exec whenever --update-crontab
+    rm -Rf /var/lib/apt/lists/* /var/cache/apt/* ~/.gemrc ~/.bundle && \
+    \
+    bundle exec whenever >crontab
 
-# Add a temporary mysql-server for assets precompilation
+# compile assets with temporary mysql server
 RUN export DATABASE_URL=mysql2://localhost/temp && \
+    export SECRET_KEY_BASE=thisisnotimportantnow && \
     export DEBIAN_FRONTEND=noninteractive && \
     apt-get update && \
     apt-get install -y mysql-server && \
     /etc/init.d/mysql start && \
     cp config/app_config.yml.SAMPLE config/app_config.yml && \
-    bundle exec rake db:setup && \
-    bundle exec rake assets:precompile && \
-    rm config/app_config.yml && \
-    rm -rf tmp/* && \
+    bundle exec rake db:setup assets:precompile && \
+    rm -Rf config/app_config.yml tmp/* && \
     /etc/init.d/mysql stop && \
-    rm -rf /run/mysqld /tmp/* /var/lib/mysql /var/log/mysql* && \
+    rm -Rf /run/mysqld /tmp/* /var/tmp/* /var/lib/mysql /var/log/mysql* && \
     apt-get purge -y --auto-remove mysql-server && \
-    rm -rf /var/lib/apt/lists/*
+    rm -Rf /var/lib/apt/lists/* /var/cache/apt/*
+
+# Make relevant dirs writable for app user
+RUN mkdir -p tmp && \
+    chown nobody tmp
+
+# Run app as unprivileged user
+USER nobody
 
 EXPOSE 3000
 
+# cleanup, and by default start web process from Procfile
 ENTRYPOINT ["./docker-entrypoint.sh"]
-CMD ["rails", "server", "--binding", "0.0.0.0"]
+CMD ["./proc-start", "web"]