apt-get install apache2 curl git default-libmysqlclient-dev mysql-server libsqlite3-dev nodejs libssl-dev libreadline-dev
  
====== rbenv or RVM ======

[[stretch:rbenv]] or [[:buster:RVM]]

====== ruby ======

  rbenv install 2.3.1 -k
  rbenv global 2.3.1
  
(-k keep source, helps compiling gems.)

====== rails ======

  gem install rails
  sudo apt-get install -y nodejs &&
  sudo ln -sf /usr/bin/nodejs /usr/local/bin/node
  sudo apt-get install sqlite3 libsqlite3-dev

Setting production server-wide:

Create ''/etc/profile.d/rails_env.sh'':

  export RAILS_ENV=production

===== Update and resolve dependency conflicts =====

Starting point for addressing many security alerts:

  # consider updating to the newest ruby
  cd /home/slack/.rbenv/plugins/ruby-build && git pull && cd -
  rbenv install x.x.x -k   # latest https://www.ruby-lang.org/en/downloads/
  rbenv local x.x.x
  
  # update bundler and gems
  gem install bundler
  bundle update --bundler
  bundle update rails

''Gemfile.lock'' is there to ensure that the production server uses exactly the same gems as in development.  If you are struggling with conflicts, you can just remove it and see what happens.

====== passenger ======

https://www.phusionpassenger.com/library/walkthroughs/deploy/ruby/ with minor modifications for rbenv -- Apache site config should contain:

    PassengerRuby /home/slack/.rbenv/shims/ruby

====== Acromatic ======

  apt install docx2txt