[doc] Adds documentation about the new image

Dockerfile

@@ -16,7 +16,7 @@ RUN apt-get update && apt-get install -y --no-install-recommends \
     wget \
     zlib1g-dev \
     file \
-    && gem install bundler --no-ri --no-rdoc \
+    && gem install bundler --no-rdoc \
     && apt-get clean \
     && rm -rf /var/lib/apt/lists/*
 

README.md

@@ -12,14 +12,28 @@ Original sources are downloaded from https://landing.google.com/sre/
 
 Requirements:
 
--   Docker
+-   Docker. See [Getting Started Guide](https://docs.docker.com/get-started/)
+
+There are two variants of the Docker Image:
+
+### All Versions (EPUB/MOBI/PDF)
 
 ```
 $ docker run --rm --volume "$(pwd):/output" captn3m0/google-sre-ebook:latest
 ```
 
--   You should see the final EPUB/MOBI/PDF files in the `output` directory after the above runs.
--   The file may be owned by the root user.
+### Only EPUB
+
+If you only require an EPUB file, there is a much slimmer image that is based on [Alpine Linux](https://alpinelinux.org/) instead of Ubuntu. (Image size is ~400MB instead of ~900MB for the all versions image). You may also use this if you already have calibre installed and can do the EPUB->MOBI or EPUB->PDF conversion elsewhere.
+
+```
+$ docker run --rm --volume "$(pwd):/output" captn3m0/google-sre-ebook:epub
+```
+
+
+### Docker Notes
+
+You should see the final EPUB/MOBI/PDF files in the `output` directory after the above runs. The generated files may be owned by the root user.
 
 **NOTE:** You'll have to allow docker access to a directory that's local to your system. The safest way to do this is as follows:
 
@@ -29,7 +43,7 @@ $ chcon -Rt svirt_sandbox_file_t /tmp/sreoutput
 $ docker run --rm --volume "/tmp/sreoutput:/output" captn3m0/google-sre-ebook:latest
 ```
 
-The build for the above Docker image can be audited at <https://cloud.docker.com/swarm/captn3m0/repository/docker/captn3m0/google-sre-ebook/builds>.
+The build for the above Docker images can be audited at <https://cloud.docker.com/swarm/captn3m0/repository/docker/captn3m0/google-sre-ebook/builds>.
 
 ## macOS
 
@@ -37,17 +51,24 @@ Review and run the `bootstrap.sh` script to generate the EPUB, MOBI, and PDF fil
 
 Requirements:
 
--   Ruby
+-   `brew install pandoc wget ruby`
 -   `gem install bundler`
 -   `bundle install`
--   `brew install pandoc`
 -   `brew cask install calibre`
--   `brew install wget`
+
+## Linux
+
+Install the `ruby-bundler`, `pandoc-bin`, `wget`, and `calibre` packages.
+
+## Running Locally
+
+This requires bundler version>=2.0. Once you have the dependencies, just run `./bootstrap.sh`
 
 # Known Issues
 
 -   metadata.xml is not complete. There are just too many authors
 -   Foreword/Preface is not part of the index
+-   Footnotes on PDFs don't work
 
 # LICENSE
 

epub.Dockerfile

@@ -17,7 +17,7 @@ COPY Gemfile* /tmp/
 
 WORKDIR /tmp
 
-RUN gem install bundler --no-ri --no-document \
+RUN gem install bundler --no-document \
     && bundle install
 
 WORKDIR /src