Beanstalk config script for Rails 6

01_rails_6_on_beanstalk.config

# Beanstalk ain't ready for Rails 6. This fix is courtesy of https://austingwalters.com/rails-6-on-elastic-beanstalk/
# Additional node 6 cleanup courtesy of https://github.com/nodesource/distributions/issues/486

commands:
  00_remove_node_6_if_present:
    command: "/bin/rm -rf /var/cache/yum && /usr/bin/yum remove -y nodejs && /bin/rm /etc/yum.repos.d/nodesource* && /usr/bin/yum clean all"
    ignoreErrors: true
  01_download_nodejs:
    command: "curl --silent --location https://rpm.nodesource.com/setup_8.x | sudo bash -"
  02_install_nodejs:
    command: "yum -y install nodejs"
  03_install_yarn:
    command: "sudo wget https://dl.yarnpkg.com/rpm/yarn.repo -O /etc/yum.repos.d/yarn.repo && sudo yum install yarn -y"
  04_mkdir_webapp_dir:
    command: "mkdir /home/webapp"
    ignoreErrors: true
  05_chown_webapp_dir:
    command: "chown webapp:webapp /home/webapp"
    ignoreErrors: true
  06_chmod_webapp_dir:
    command: "chmod 0744 /home/webapp"
    ignoreErrors: true
  07_chmod_logs:
    command: "chown webapp:webapp -R /var/app/current/log/"
    ignoreErrors: true
  08_create_log_file:
    command: "touch /var/app/current/log/production.log"
    ignoreErrors: true
  09_chown_log_production:
    command: "chown webapp:webapp /var/app/current/log/production.log"
    ignoreErrors: true
  10_chmod_log_dir:
    command: "chmod 0664 -R /var/app/current/log/"
    ignoreErrors: true
  11_update_bundler:
    command: "gem update bundler"
    ignoreErrors: true
  12_config_for_update_nokogiri:
    command: "bundle config build.nokogiri --use-system-libraries"
  13_chown_current:
    command: "chown webapp:webapp -R /var/app/current/"
    ignoreErrors: true
  14_chmod_current:
    command: "chmod 0755 -R /var/app/current/"
    ignoreErrors: true
  15_chown_current:
    command: "chown webapp:webapp -R /var/app/ondeck/"
    ignoreErrors: true
  16_chown_current:
    command: "chmod 0644 -R /var/app/ondeck/"
    ignoreErrors: true

container_commands:

  17_install_webpack:
    command: "npm install --save-dev webpack"
  18_config_for_update_nokogiri:
    command: "bundle config build.nokogiri --use-system-libraries"
  19_precompile:
    command: "bundle exec rake assets:precompile"

What is that folder? I have tried to search for the same bud didn't found anything.

/var/app/ondeck/

That is where pre-AL2 beanstalk environments stage the app before deploying to var/app/current. On AL2 I believe it is var/app/staging instead.