Ensure Dockerfile installs commonly needed packages

railties/lib/rails/generators/app_base.rb

@@ -457,6 +457,46 @@ def dockerfile_binfile_fixups
         binfixups
       end
 
+      def dockerfile_packages
+        # start with the essentials
+        packages = %w(build-essential git)
+
+        # add databases: sqlite3, postgres, mysql
+        packages += %w(pkg-config libpq-dev default-libmysqlclient-dev)
+
+        # add redis in case Action Cable, caching, or sidekiq are added later
+        packages << "redis"
+
+        # ActiveStorage preview support
+        packages << "libvips" unless skip_active_storage?
+
+        # node support, including support for building native modules
+        if using_node?
+          packages += %w(curl node-gyp) # pkg-config already listed above
+
+          # module build process depends on Python, and debian changed
+          # how python is installed with the bullseye release.  Below
+          # is based on debian release included with the Ruby images on
+          # Dockerhub.
+          case Gem.ruby_version
+          when /^2.7/
+            bullseye = ruby_version >= "2.7.4"
+          when /^3.0/
+            bullseye = ruby_version >= "3.0.2"
+          else
+            bullseye = true
+          end
+
+          if bullseye
+            packages << "python-is-python3"
+          else
+            packages << "python"
+          end
+        end
+
+        packages.sort
+      end
+
       # CSS processors other than Tailwind require a node-based JavaScript environment. So overwrite the normal JS default
       # if one such processor has been specified.
       def adjusted_javascript_option

railties/lib/rails/generators/rails/app/templates/Dockerfile.tt

@@ -1,24 +1,22 @@
 # Make sure it matches the Ruby version in .ruby-version and Gemfile
 ARG RUBY_VERSION=<%= Gem.ruby_version %>
-FROM ruby:$RUBY_VERSION
+FROM ruby:$RUBY_VERSION-slim
+
+# Install packages need to build gems<%= using_node? ? " and node modules" : "" %>
+RUN apt-get update -qq && \
+    apt-get install -y <%= dockerfile_packages.join(" ") %> && \
+    apt-get clean && \
+    rm -rf /var/lib/apt/lists/* /usr/share/doc /usr/share/man
 
 <% if using_node? -%>
 # Install JavaScript dependencies
 ARG NODE_VERSION=<%= dockerfile_node_version %>
 ARG YARN_VERSION=<%= dockerfile_yarn_version %>
 ENV VOLTA_HOME="/root/.volta" \
-    PATH="$VOLTA_HOME/bin:/usr/local/bin:$PATH"
+    PATH="/root/.volta/bin:$PATH"
 RUN curl https://get.volta.sh | bash && \
     volta install node@$NODE_VERSION yarn@$YARN_VERSION
 
-<% end -%>
-<% if !skip_active_storage? -%>
-# Install libvips for Active Storage preview support
-RUN apt-get update -qq && \
-    apt-get install -y build-essential libvips && \
-    apt-get clean && \
-    rm -rf /var/lib/apt/lists/* /usr/share/doc /usr/share/man
-
 <% end -%>
 # Rails app lives here
 WORKDIR /rails
@@ -56,4 +54,4 @@ ENTRYPOINT ["/rails/bin/docker-entrypoint"]
 
 # Start the server by default, this can be overwritten at runtime
 EXPOSE 3000
-CMD ["./bin/rails", "server"]
+CMD ["./bin/rails", "server"]

railties/test/generators/app_generator_test.rb

@@ -772,6 +772,7 @@ def test_webpack_option
 
     assert_file "Dockerfile" do |content|
       assert_match(/yarn/, content)
+      assert_match(/node-gyp/, content)
     end
 
     assert_file ".node-version" do |content|
@@ -1042,6 +1043,7 @@ def test_dockerfile
       assert_match(/assets:precompile/, content)
       assert_match(/libvips/, content)
       assert_no_match(/yarn/, content)
+      assert_no_match(/node-gyp/, content)
     end
   end