Dockerfile

# syntax = docker/dockerfile:1

# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
# docker build -t my-app .
# docker run -d -p 80:80 -p 443:443 --name my-app -e RAILS_MASTER_KEY=<value from config/master.key> my-app

# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
ARG RUBY_VERSION=3.3.4
FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base

# Rails app lives here
WORKDIR /rails

# Install base packages
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y curl libjemalloc2 libvips postgresql-client && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

# Set production environment
ENV RAILS_ENV="production" \
    BUNDLE_DEPLOYMENT="1" \
    BUNDLE_PATH="/usr/local/bundle" \
    BUNDLE_WITHOUT="development"

# Throw-away build stage to reduce size of final image
FROM base AS build

# Install packages needed to build gems
RUN apt-get update -qq && \
    apt-get install --no-install-recommends -y build-essential git libpq-dev pkg-config automake libtool libffi-dev libssl-dev libgmp-dev python3-dev nodejs && \
    rm -rf /var/lib/apt/lists /var/cache/apt/archives

RUN ARCH= OPENSSL_ARCH= && dpkgArch="$(dpkg --print-architecture)" && NODE_VERSION=20.10.0 \
    && case "${dpkgArch##*-}" in \
      amd64) ARCH='x64' OPENSSL_ARCH='linux-x86_64';; \
      ppc64el) ARCH='ppc64le' OPENSSL_ARCH='linux-ppc64le';; \
      s390x) ARCH='s390x' OPENSSL_ARCH='linux*-s390x';; \
      arm64) ARCH='arm64' OPENSSL_ARCH='linux-aarch64';; \
      armhf) ARCH='armv7l' OPENSSL_ARCH='linux-armv4';; \
      i386) ARCH='x86' OPENSSL_ARCH='linux-elf';; \
      *) echo "unsupported architecture"; exit 1 ;; \
    esac \
    && set -ex \
    && apt-get update && apt-get install -y ca-certificates curl wget gnupg dirmngr xz-utils libatomic1 --no-install-recommends \
    && rm -rf /var/lib/apt/lists/* \
    && export GNUPGHOME="$(mktemp -d)" \
    && for key in \
      4ED778F539E3634C779C87C6D7062848A1AB005C \
      141F07595B7B3FFE74309A937405533BE57C7D57 \
      74F12602B6F1C4E913FAA37AD3A89613643B6201 \
      DD792F5973C6DE52C432CBDAC77ABFA00DDBF2B7 \
      61FC681DFB92A079F1685E77973F295594EC4689 \
      8FCCA13FEF1D0C2E91008E09770F7A9A5AE15600 \
      C4F0DFFF4E8C1A8236409D08E73BC641CC11F4C8 \
      890C08DB8579162FEE0DF9DB8BEAB4DFCF555EF4 \
      C82FA3AE1CBEDC6BE46B9360C43CEC45C17AB93C \
      108F52B48DB57BB0CC439B2997B01419BD92F80A \
      A363A499291CBBC940DD62E41F10027AF002F8B0 \
      CC68F5A3106FF448322E48ED27F5E38D5B0A215F \
    ; do \
      gpg --batch --keyserver hkps://keys.openpgp.org --recv-keys "$key" || \
      gpg --batch --keyserver keyserver.ubuntu.com --recv-keys "$key" ; \
    done \
    && curl -fsSLO --compressed "https://nodejs.org/dist/v$NODE_VERSION/node-v$NODE_VERSION-linux-$ARCH.tar.xz" \
    && curl -fsSLO --compressed "https://nodejs.org/dist/v$NODE_VERSION/SHASUMS256.txt.asc" \
    && gpg --batch --decrypt --output SHASUMS256.txt SHASUMS256.txt.asc \
    && gpgconf --kill all \
    && rm -rf "$GNUPGHOME" \
    && grep " node-v$NODE_VERSION-linux-$ARCH.tar.xz\$" SHASUMS256.txt | sha256sum -c - \
    && tar -xJf "node-v$NODE_VERSION-linux-$ARCH.tar.xz" -C /usr/local --strip-components=1 --no-same-owner \
    && rm "node-v$NODE_VERSION-linux-$ARCH.tar.xz" SHASUMS256.txt.asc SHASUMS256.txt \
    && find /usr/local/include/node/openssl/archs -mindepth 1 -maxdepth 1 ! -name "$OPENSSL_ARCH" -exec rm -rf {} \; \
    && apt-mark auto '.*' > /dev/null \
    && find /usr/local -type f -executable -exec ldd '{}' ';' \
      | awk '/=>/ { so = $(NF-1); if (index(so, "/usr/local/") == 1) { next }; gsub("^/(usr/)?", "", so); print so }' \
      | sort -u \
      | xargs -r dpkg-query --search \
      | cut -d: -f1 \
      | sort -u \
      | xargs -r apt-mark manual \
    && apt-get purge -y --auto-remove -o APT::AutoRemove::RecommendsImportant=false \
    && ln -s /usr/local/bin/node /usr/local/bin/nodejs \
    && node --version \
    && npm --version

# Install application gems
COPY Gemfile Gemfile.lock ./
RUN bundle install && \
    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
    bundle exec bootsnap precompile --gemfile && npm install

# Copy application code
COPY . .

# Precompile bootsnap code for faster boot times
RUN bundle exec bootsnap precompile app/ lib/

# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile




# Final stage for app image
FROM base

# Copy built artifacts: gems, application
COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
COPY --from=build /rails /rails

# Run and own only the runtime files as a non-root user for security
RUN groupadd --system --gid 1000 rails && \
    useradd rails --uid 1000 --gid 1000 --create-home --shell /bin/bash && \
    chown -R rails:rails db log storage tmp
USER 1000:1000

# Entrypoint prepares the database.
ENTRYPOINT ["/rails/bin/docker-entrypoint"]

# Start the server by default, this can be overwritten at runtime
EXPOSE 3000
CMD ["./bin/rails", "server"]