Group RUN commands - reduce image size

Dockerfile

@@ -1,14 +1,6 @@
 # Use the official Ruby 3.2.0 Alpine image as the base image
 FROM ruby:3.2.0-alpine
 
-# Install system dependencies
-RUN apk add --no-cache build-base
-
-RUN gem install bundler --version=2.4.3
-
-# Create a directory for your application
-RUN mkdir -p /mrsk
-
 # Set the working directory to /mrsk
 WORKDIR /mrsk
 
@@ -18,15 +10,25 @@ COPY Gemfile Gemfile.lock mrsk.gemspec ./
 # Required in mrsk.gemspec
 COPY lib/mrsk/version.rb /mrsk/lib/mrsk/version.rb
 
-# Install gems
-RUN bundle install
+# Install system dependencies
+RUN apk add --no-cache --update build-base git docker openrc \
+    && rc-update add docker boot \
+    && gem install bundler --version=2.4.3 \
+    && mkdir -p /mrsk \
+    && bundle install
 
-# Copy the rest of your application code into the container
+# Copy the rest of our application code into the container.
+# We do this after bundle install, to avoid having to run bundle
+# everytime we do small fixes in the source code.
 COPY . .
 
 # Install the gem locally from the project folder
 RUN gem build mrsk.gemspec && \
     gem install ./mrsk-*.gem --no-document
 
-# Set the entrypoint to run the installed binary
-ENTRYPOINT ["mrsk"]
+# Set the working directory to /workdir
+WORKDIR /workdir
+
+# Set the entrypoint to run the installed binary in /workdir
+# Example:  docker run -it -v "$PWD:/workdir" mrsk init
+ENTRYPOINT ["mrsk"]