Deploy Ruby on Rails on Oracle Cloud's free tier

At a glance

Running Ruby on Rails on Ampere ARM

Native gems (pg, nokogiri, bcrypt) compile cleanly on Ampere but add a minute or two to cold builds; layer caching makes subsequent deploys fast.

Steps

1. Precompile assets in the image. Use a dummy SECRET_KEY_BASE at build time so precompilation does not need production secrets.
2. Run Sidekiq as a second container. Same image, different command — no extra dyno cost because it is your own VM.
3. Migrate before the traffic switch. Add `rails db:migrate` as a release step.

Dockerfile for Ruby on Rails on ARM64

FROM ruby:3.3-alpine
WORKDIR /app
RUN apk add --no-cache build-base postgresql-dev tzdata nodejs yarn
COPY Gemfile Gemfile.lock ./
RUN bundle config set --local without 'development test' && bundle install
COPY . .
ENV RAILS_ENV=production RAILS_SERVE_STATIC_FILES=true RAILS_LOG_TO_STDOUT=true
RUN SECRET_KEY_BASE=dummy bundle exec rails assets:precompile
EXPOSE 3000
CMD ["bundle", "exec", "puma", "-C", "config/puma.rb"]

Need one tailored to your repository? The free Dockerfile generator writes an ARM-ready multi-stage build for you.

Common mistakes

• Missing tzdata: Alpine images need tzdata or Rails raises on timezone lookups.
• Serving assets: Set RAILS_SERVE_STATIC_FILES unless a proxy serves public/ for you.
• Active Storage on local disk: Mount a volume or use Oracle Object Storage, or uploads vanish on redeploy.

Related reading

• /alternatives/heroku-free-2026
• /compare/heroku-alternatives-free
• /guides/self-host-docker
• All deployment guides