Copy bun's executable from official image instead of installing

lib/generators/templates/Dockerfile.erb

@@ -71,6 +71,15 @@ FROM prebuild AS <% if using_bun? %>bun<% else %>node<% end %>
 
 <% end -%>
 <% if using_bun? and (!using_execjs? || File.exist?('bun.lockb') || File.exist?('bun.lock')) -%>
+<% if bun_version -%>
+ARG BUN_VERSION=<%= bun_version %>
+<% end -%>
+<% if options.alpine? -%>
+FROM oven/bun:<%= bun_version ? '${BUN_VERSION}' : '1' %>-alpine AS bun
+<% else -%>
+FROM oven/bun:<%= bun_version ? '${BUN_VERSION}' : '1' %>-debian AS bun
+<% end -%>
+
 <%= render partial: 'install_node', locals: {bun_version: using_execjs? ? nil : bun_version} %>
 
 <% elsif using_node? and (!using_execjs? || File.exist?('yarn.lock')) -%>

lib/generators/templates/_install_node.erb

@@ -1,11 +1,7 @@
 <% if using_bun? -%>
-# Install Bun
-<% if bun_version -%>
-ARG BUN_VERSION=<%= bun_version %>
-<% end -%>
-ENV BUN_INSTALL=/usr/local/bun
-ENV PATH=/usr/local/bun/bin:$PATH
-RUN curl -fsSL https://bun.sh/install | bash<% if bun_version %> -s -- "bun-v${BUN_VERSION}"<% end %>
+# Copy Bun from official image
+COPY --from=bun /usr/local/bin/bun /usr/local/bin/bun
+ENV PATH=/usr/local/bin:$PATH
 <% else -%>
 <% if node_version and yarn_version -%>
 # Install JavaScript dependencies

test/results/bun/Dockerfile

@@ -38,11 +38,12 @@ RUN apt-get update -qq && \
     apt-get install --no-install-recommends -y build-essential libyaml-dev pkg-config unzip && \
     rm -rf /var/lib/apt/lists /var/cache/apt/archives
 
-# Install Bun
 ARG BUN_VERSION=xxx
-ENV BUN_INSTALL=/usr/local/bun
-ENV PATH=/usr/local/bun/bin:$PATH
-RUN curl -fsSL https://bun.sh/install | bash -s -- "bun-v${BUN_VERSION}"
+FROM oven/bun:${BUN_VERSION}-debian AS bun
+
+# Copy Bun from official image
+COPY --from=bun /usr/local/bin/bun /usr/local/bin/bun
+ENV PATH=/usr/local/bin:$PATH
 
 # Install application gems
 COPY Gemfile Gemfile.lock ./

test/results/bun_alpine/Dockerfile

@@ -0,0 +1,90 @@
+# syntax=docker/dockerfile:1
+# check=error=true
+
+# This Dockerfile is designed for production, not development. Use with Kamal or build'n'run by hand:
+# docker build -t demo .
+# docker run -d -p 80:80 -e RAILS_MASTER_KEY=<value from config/master.key> --name demo demo
+
+# For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html
+
+# Make sure RUBY_VERSION matches the Ruby version in .ruby-version
+ARG RUBY_VERSION=xxx
+FROM ruby:$RUBY_VERSION-alpine AS base
+
+# Rails app lives here
+WORKDIR /rails
+
+# Update gems and bundler
+RUN gem update --system --no-document && \
+    gem install -N bundler
+
+# Install base packages
+RUN apk add --no-cache curl jemalloc sqlite tzdata
+
+# Set production environment
+ENV BUNDLE_DEPLOYMENT="1" \
+    BUNDLE_PATH="/usr/local/bundle" \
+    BUNDLE_WITHOUT="development:test" \
+    RAILS_ENV="production"
+
+
+# Throw-away build stage to reduce size of final image
+FROM base AS build
+
+# Install packages needed to build gems
+RUN apk add --no-cache build-base pkgconfig unzip yaml-dev
+
+ARG BUN_VERSION=xxx
+FROM oven/bun:${BUN_VERSION}-alpine AS bun
+
+# Copy Bun from official image
+COPY --from=bun /usr/local/bin/bun /usr/local/bin/bun
+ENV PATH=/usr/local/bin:$PATH
+
+# Install application gems
+COPY Gemfile Gemfile.lock ./
+RUN bundle install && \
+    rm -rf ~/.bundle/ "${BUNDLE_PATH}"/ruby/*/cache "${BUNDLE_PATH}"/ruby/*/bundler/gems/*/.git && \
+    bundle exec bootsnap precompile --gemfile
+
+# Install node modules
+COPY package.json bun.lock ./
+RUN bun install --frozen-lockfile --production
+
+# Copy application code
+COPY . .
+
+# Precompile bootsnap code for faster boot times
+RUN bundle exec bootsnap precompile app/ lib/
+
+# Precompiling assets for production without requiring secret RAILS_MASTER_KEY
+RUN SECRET_KEY_BASE_DUMMY=1 ./bin/rails assets:precompile
+
+
+# Final stage for app image
+FROM base
+
+# Install packages needed for deployment
+RUN apk add --no-cache sqlite-libs
+
+# Copy built artifacts: gems, application
+COPY --from=build "${BUNDLE_PATH}" "${BUNDLE_PATH}"
+COPY --from=build /rails /rails
+
+# Run and own only the runtime files as a non-root user for security
+RUN addgroup --system --gid 1000 rails && \
+    adduser --system rails --uid 1000 --ingroup rails --home /home/rails --shell /bin/sh rails && \
+    mkdir /data && \
+    chown -R 1000:1000 db log storage tmp /data
+USER 1000:1000
+
+# Deployment options
+ENV DATABASE_URL="sqlite3:///data/production.sqlite3"
+
+# Entrypoint prepares the database.
+ENTRYPOINT ["/rails/bin/docker-entrypoint"]
+
+# Start server via Thruster by default, this can be overwritten at runtime
+EXPOSE 80
+VOLUME /data
+CMD ["./bin/thrust", "./bin/rails", "server"]

test/test_bun_alpine.rb

@@ -0,0 +1,12 @@
+# frozen_string_literal: true
+
+require_relative "base"
+
+class TestBunAlpine < TestBase
+  @rails_options = "--javascript bun"
+  @generate_options = "--alpine"
+
+  def test_bun_alpine
+    check_dockerfile
+  end
+end