oracle client capistrano install task: useful when ruby-oci8 is required in a server

deploy.rb

...
set :default_environment, { 
 'LD_LIBRARY_PATH' => "#{shared_dir}/oracle/"
}

oracle.rb

def remote_file_exists?(full_path)
  'true' ==  capture("if [ -e #{full_path} ]; then echo 'true'; fi").strip
end

namespace :oracle do
  task :install do
    instant_client = "instantclient-basic-linux.x64-12.1.0.1.0.zip"
    instant_client_sdk = "instantclient-sdk-linux.x64-12.1.0.1.0.zip"
    oracle_path = "#{shared_path}/oracle/"
    instant_client_path = "#{oracle_path}instantclient_12_1"
    run "#{sudo} apt-get -y update"
    run "#{sudo} apt-get -y install libaio1 unzip"
    run "mkdir -p #{oracle_path}" 
    unless remote_file_exists?(instant_client_path)
      upload File.expand_path("../templates/oracle/#{instant_client}", __FILE__), "#{oracle_path}#{instant_client}"
      upload File.expand_path("../templates/oracle/#{instant_client_sdk}", __FILE__), "#{oracle_path}#{instant_client_sdk}"
      run "cd #{oracle_path}; unzip #{instant_client_sdk}" 
      run "cd #{oracle_path}; unzip #{instant_client}" 
      run "cd #{instant_client_path}; ln -s libclntsh.so.12.1 libclntsh.so"
      put "#{instant_client_path}", "/tmp/oracle.conf"
      run "#{sudo} mv /tmp/oracle.conf /etc/ld.so.conf.d/oracle.conf"
      run "sudo ldconfig"
    end
  end
  after "deploy:install", "oracle:install"

end