diff --git a/.bundle/config b/.bundle/config
new file mode 100644
index 0000000000000..2369228816d46
--- /dev/null
+++ b/.bundle/config
@@ -0,0 +1,2 @@
+---
+BUNDLE_PATH: "vendor/bundle"
diff --git a/.dockerignore b/.dockerignore
new file mode 100644
index 0000000000000..5381ad50b730c
--- /dev/null
+++ b/.dockerignore
@@ -0,0 +1,2 @@
+*
+!Gemfile*
diff --git a/.gitignore b/.gitignore
index b4038acab8641..8e19eaabb3144 100644
--- a/.gitignore
+++ b/.gitignore
@@ -18,8 +18,7 @@ bin
 !html/sitemap.xml
 metastore_db
 html_docs/
-!resources/asciidoctor/**/bin
-resources/asciidoctor/vendor/**/cache
+vendor
 
 # Comes from running tests in resources/asciidoctor
 resources/asciidoctor/build
diff --git a/Dockerfile b/Dockerfile
index ca05909ce3e8e..a6799e2b9c138 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -52,24 +52,6 @@ RUN install_packages \
 # have to be empty. So we delete them.
 RUN rm -rf /var/log/nginx && rm -rf /run
 
-# Gem inventory:
-# * Used by the docs build
-#   * asciidoctor
-#   * thread_safe
-# * Speculative
-#   * asciidoctor-diagram
-#   * asciimath
-# * Used to check the build in CI
-#   * rubocop
-#   * rspec
-RUN gem install --no-document \
-  asciidoctor:1.5.8 \
-  asciidoctor-diagram:1.5.12 \
-  asciimath:1.0.8 \
-  rubocop:0.64.0 \
-  rspec:3.8.0 \
-  thread_safe:0.3.6
-
 # Wheel inventory:
 # * Used to test the docs build
 #   * beautifulsoup4
@@ -79,3 +61,14 @@ RUN pip3 install \
   beautifulsoup4==4.7.1 \
   lxml==4.3.1 \
   pycodestyle==2.5.0
+
+# Install ruby deps with bundler to make things more standard for Ruby folks.
+RUN gem install bundler:2.0.1
+RUN bundle config --global silence_root_warning 1
+COPY Gemfile* /
+RUN bundle install --binstubs --system --frozen
+# --frozen forces us to regenerate Gemfile.lock locally before using it in
+# docker which is important because we need Gemfile.lock to lock the gems to a
+# consistent version and we can't rely on running bundler in docker to update
+# it because we can't copy from the image to the host machine while building
+# the image.
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 0000000000000..c402a99f5f481
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,18 @@
+# IMPORTANT: If you change this file you should run `bundle lock` to
+# regenerate Gemfile.lock or building the docker image will fail.
+source "https://rubygems.org"
+
+ruby "~> 2.3"
+
+# We commit Gemfile.lock so we're not going to have "unexpected" version bumps
+# of our gems. This file specifies what we think *should* work. Gemfile.lock
+# specifies what we *know* does work.
+gem "asciidoctor", "~> 1.5"          # Used by the docs build
+gem "thread_safe", "~> 0.3.6"        # Used by asciidoctor
+gem "asciidoctor-diagram", "~> 1.5"  # Speculative
+gem "asciimath", "~> 1.0"            # Speculative
+
+group :test do
+  gem "rspec", "~> 3.8"
+  gem "rubocop", "~> 0.64.0"
+end
diff --git a/Gemfile.lock b/Gemfile.lock
new file mode 100644
index 0000000000000..1c425240a3811
--- /dev/null
+++ b/Gemfile.lock
@@ -0,0 +1,56 @@
+GEM
+  remote: https://rubygems.org/
+  specs:
+    asciidoctor (1.5.8)
+    asciidoctor-diagram (1.5.12)
+      asciidoctor (~> 1.5.0)
+    asciimath (1.0.8)
+    ast (2.4.0)
+    diff-lcs (1.3)
+    jaro_winkler (1.5.2)
+    parallel (1.16.2)
+    parser (2.6.2.0)
+      ast (~> 2.4.0)
+    powerpack (0.1.2)
+    rainbow (3.0.0)
+    rspec (3.8.0)
+      rspec-core (~> 3.8.0)
+      rspec-expectations (~> 3.8.0)
+      rspec-mocks (~> 3.8.0)
+    rspec-core (3.8.0)
+      rspec-support (~> 3.8.0)
+    rspec-expectations (3.8.2)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.8.0)
+    rspec-mocks (3.8.0)
+      diff-lcs (>= 1.2.0, < 2.0)
+      rspec-support (~> 3.8.0)
+    rspec-support (3.8.0)
+    rubocop (0.64.0)
+      jaro_winkler (~> 1.5.1)
+      parallel (~> 1.10)
+      parser (>= 2.5, != 2.5.1.1)
+      powerpack (~> 0.1)
+      rainbow (>= 2.2.2, < 4.0)
+      ruby-progressbar (~> 1.7)
+      unicode-display_width (~> 1.4.0)
+    ruby-progressbar (1.10.0)
+    thread_safe (0.3.6)
+    unicode-display_width (1.4.1)
+
+PLATFORMS
+  ruby
+
+DEPENDENCIES
+  asciidoctor (~> 1.5)
+  asciidoctor-diagram (~> 1.5)
+  asciimath (~> 1.0)
+  rspec (~> 3.8)
+  rubocop (~> 0.64.0)
+  thread_safe (~> 0.3.6)
+
+RUBY VERSION
+   ruby 2.5.3p105
+
+BUNDLED WITH
+   1.17.1
diff --git a/build_docs b/build_docs
index b68440fe213b6..12f80605914a6 100755
--- a/build_docs
+++ b/build_docs
@@ -67,7 +67,7 @@ def build_docker_image():
             else:
                 acc.append(line)
 
-        cmd = ["docker", "image", "build", "-t", "elastic/docs_build", "-"]
+        cmd = ["docker", "image", "build", "-t", "elastic/docs_build", DIR]
         build = common_popen(cmd, dockerfile)
         handle_popen(build, handle_line)
         if build.returncode != 0:
diff --git a/resources/asciidoctor/README b/resources/asciidoctor/README
index 5aeb409088683..e777151b16bbd 100644
--- a/resources/asciidoctor/README
+++ b/resources/asciidoctor/README
@@ -1,3 +1,12 @@
 These are Elastic's extensions to Asciidoctor! The `lib` directory contains
 the actual extensions and the spec directory contains the tests. You can run
-the tests with `build_docs --self-test`.
\ No newline at end of file
+the tests with `build_docs --self-test` to reproduce the authoritative, in
+docker tests. You can also use more ruby standard stuff like:
+
+```
+bundle install
+bundle exec rspec
+bundle exec rubocop
+```
+
+but it is not authoritative.