diff --git a/.kokoro/build.bat b/.kokoro/build.bat
new file mode 100644
index 00000000..5ff89c88
--- /dev/null
+++ b/.kokoro/build.bat
@@ -0,0 +1,16 @@
+REM This file runs tests for merges, PRs, and nightlies.
+REM There are a few rules for what tests are run:
+REM  * PRs run all non-acceptance tests for every library.
+REM  * Merges run all non-acceptance tests for every library, and acceptance tests for all altered libraries.
+REM  * Nightlies run all acceptance tests for every library.
+REM Currently only runs tests on 2.5.1
+
+SET url="https://raw.githubusercontent.com/googleapis/google-cloud-ruby/master/.kokoro/build.bat"
+
+SET "download=powershell -C Invoke-WebRequest -Uri %url% -OutFile master-build.bat"
+
+SET EXIT_STATUS=1
+
+%download% && master-build.bat && SET EXIT_STATUS=0
+
+EXIT %EXIT_STATUS%
diff --git a/.kokoro/build.sh b/.kokoro/build.sh
new file mode 100755
index 00000000..7f4e00fb
--- /dev/null
+++ b/.kokoro/build.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+script_url="https://raw.githubusercontent.com/googleapis/google-cloud-ruby/master/.kokoro/build.sh"
+curl -o master-build.sh $script_url && source master-build.sh
diff --git a/.kokoro/continuous/common.cfg b/.kokoro/continuous/common.cfg
new file mode 100644
index 00000000..0dd62354
--- /dev/null
+++ b/.kokoro/continuous/common.cfg
@@ -0,0 +1,24 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Build logs will be here
+action {
+  define_artifacts {
+    regex: "**/*sponge_log.xml"
+  }
+}
+
+# Download trampoline resources.
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
+
+# Download resources for system tests (service account key, etc.)
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-ruby"
+
+env_vars: {
+    key: "JOB_TYPE"
+    value: "continuous"
+}
+
+env_vars: {
+    key: "REPO_DIR"
+    value: "github/getting-started-ruby"
+}
diff --git a/.kokoro/continuous/linux.cfg b/.kokoro/continuous/linux.cfg
new file mode 100644
index 00000000..08fc7b71
--- /dev/null
+++ b/.kokoro/continuous/linux.cfg
@@ -0,0 +1,25 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/trampoline.sh"
+
+# Configure the docker image for kokoro-trampoline.
+# Dockerfile is maintained at https://github.com/googleapis/google-cloud-ruby/tree/master/.kokoro/docker/multi
+env_vars: {
+    key: "TRAMPOLINE_IMAGE"
+    value: "gcr.io/cloud-devrel-kokoro-resources/yoshi-ruby/multi"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/getting-started-ruby/.kokoro/build.sh"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_SCRIPT"
+    value: "trampoline_v1.py"
+}
+
+env_vars: {
+    key: "OS"
+    value: "linux"
+}
diff --git a/.kokoro/continuous/osx.cfg b/.kokoro/continuous/osx.cfg
new file mode 100644
index 00000000..75eba531
--- /dev/null
+++ b/.kokoro/continuous/osx.cfg
@@ -0,0 +1,8 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/osx.sh"
+
+env_vars: {
+    key: "OS"
+    value: "osx"
+}
diff --git a/.kokoro/continuous/post.cfg b/.kokoro/continuous/post.cfg
new file mode 100644
index 00000000..8603496c
--- /dev/null
+++ b/.kokoro/continuous/post.cfg
@@ -0,0 +1,30 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/trampoline.sh"
+
+# Configure the docker image for kokoro-trampoline.
+# Dockerfile is maintained at https://github.com/googleapis/google-cloud-ruby/tree/master/.kokoro/docker/multi-node
+env_vars: {
+    key: "TRAMPOLINE_IMAGE"
+    value: "gcr.io/cloud-devrel-kokoro-resources/yoshi-ruby/multi-node"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/getting-started-ruby/.kokoro/build.sh"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_SCRIPT"
+    value: "trampoline_v1.py"
+}
+
+env_vars: {
+    key: "OS"
+    value: "linux"
+}
+
+env_vars: {
+    key: "JOB_TYPE"
+    value: "post"
+}
diff --git a/.kokoro/continuous/windows.cfg b/.kokoro/continuous/windows.cfg
new file mode 100644
index 00000000..023a32fe
--- /dev/null
+++ b/.kokoro/continuous/windows.cfg
@@ -0,0 +1,29 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/trampoline.bat"
+
+# Configure the docker image for kokoro-trampoline.
+env_vars: {
+    key: "TRAMPOLINE_IMAGE"
+    value: "gcr.io/cloud-devrel-kokoro-resources/yoshi-ruby/windows"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/getting-started-ruby/.kokoro/build.bat"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_SCRIPT"
+    value: "trampoline_windows.py"
+}
+
+env_vars: {
+    key: "REPO_DIR"
+    value: "getting-started-ruby"
+}
+
+env_vars: {
+    key: "OS"
+    value: "windows"
+}
diff --git a/.kokoro/osx.sh b/.kokoro/osx.sh
new file mode 100755
index 00000000..8be8ec05
--- /dev/null
+++ b/.kokoro/osx.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+script_url="https://raw.githubusercontent.com/googleapis/google-cloud-ruby/master/.kokoro/osx.sh"
+curl -o master-osx.sh $script_url && source master-osx.sh
diff --git a/.kokoro/presubmit/common.cfg b/.kokoro/presubmit/common.cfg
new file mode 100644
index 00000000..bb0eb58a
--- /dev/null
+++ b/.kokoro/presubmit/common.cfg
@@ -0,0 +1,24 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+# Build logs will be here
+action {
+  define_artifacts {
+    regex: "**/*sponge_log.xml"
+  }
+}
+
+# Download trampoline resources.
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/trampoline"
+
+# Download resources for system tests (service account key, etc.)
+gfile_resources: "/bigstore/cloud-devrel-kokoro-resources/google-cloud-ruby"
+
+env_vars: {
+    key: "JOB_TYPE"
+    value: "presubmit"
+}
+
+env_vars: {
+    key: "REPO_DIR"
+    value: "github/getting-started-ruby"
+}
diff --git a/.kokoro/presubmit/linux.cfg b/.kokoro/presubmit/linux.cfg
new file mode 100644
index 00000000..a0ca6dcd
--- /dev/null
+++ b/.kokoro/presubmit/linux.cfg
@@ -0,0 +1,24 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/trampoline.sh"
+
+# Configure the docker image for kokoro-trampoline.
+env_vars: {
+    key: "TRAMPOLINE_IMAGE"
+    value: "gcr.io/cloud-devrel-kokoro-resources/yoshi-ruby/multi"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/getting-started-ruby/.kokoro/build.sh"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_SCRIPT"
+    value: "trampoline_v1.py"
+}
+
+env_vars: {
+    key: "OS"
+    value: "linux"
+}
diff --git a/.kokoro/presubmit/osx.cfg b/.kokoro/presubmit/osx.cfg
new file mode 100644
index 00000000..75eba531
--- /dev/null
+++ b/.kokoro/presubmit/osx.cfg
@@ -0,0 +1,8 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/osx.sh"
+
+env_vars: {
+    key: "OS"
+    value: "osx"
+}
diff --git a/.kokoro/presubmit/windows.cfg b/.kokoro/presubmit/windows.cfg
new file mode 100644
index 00000000..023a32fe
--- /dev/null
+++ b/.kokoro/presubmit/windows.cfg
@@ -0,0 +1,29 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+build_file: "getting-started-ruby/.kokoro/trampoline.bat"
+
+# Configure the docker image for kokoro-trampoline.
+env_vars: {
+    key: "TRAMPOLINE_IMAGE"
+    value: "gcr.io/cloud-devrel-kokoro-resources/yoshi-ruby/windows"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/getting-started-ruby/.kokoro/build.bat"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_SCRIPT"
+    value: "trampoline_windows.py"
+}
+
+env_vars: {
+    key: "REPO_DIR"
+    value: "getting-started-ruby"
+}
+
+env_vars: {
+    key: "OS"
+    value: "windows"
+}
diff --git a/.kokoro/trampoline.bat b/.kokoro/trampoline.bat
new file mode 100644
index 00000000..1634b071
--- /dev/null
+++ b/.kokoro/trampoline.bat
@@ -0,0 +1,10 @@
+
+SET url="https://raw.githubusercontent.com/googleapis/google-cloud-ruby/master/.kokoro/trampoline.bat"
+
+SET "download=powershell -C Invoke-WebRequest -Uri %url% -OutFile master-trampoline.bat"
+
+SET EXIT_STATUS=1
+
+%download% && master-trampoline.bat && SET EXIT_STATUS=0
+
+EXIT %EXIT_STATUS%
diff --git a/.kokoro/trampoline.sh b/.kokoro/trampoline.sh
new file mode 100755
index 00000000..4325866e
--- /dev/null
+++ b/.kokoro/trampoline.sh
@@ -0,0 +1,4 @@
+#!/bin/bash
+
+script_url="https://raw.githubusercontent.com/googleapis/google-cloud-ruby/master/.kokoro/trampoline.sh"
+curl -o master-trampoline.sh $script_url && source master-trampoline.sh
diff --git a/.rubocop.yml b/.rubocop.yml
new file mode 100644
index 00000000..7c3191e5
--- /dev/null
+++ b/.rubocop.yml
@@ -0,0 +1,19 @@
+inherit_gem:
+    google-style: google-style.yml
+
+AllCops:
+    Exclude:
+        - "**/spec/**/*.rb"
+        - "Rakefile"
+
+Metrics/BlockLength:
+    Exclude:
+        - "**/*test.rb"
+Style/Documentation:
+    Enabled: false
+Style/GuardClause:
+    Enabled: false
+Style/MixinUsage:
+    Exclude:
+        - "bookshelf/**/*"
+        - "**/*test.rb"
diff --git a/Gemfile b/Gemfile
new file mode 100644
index 00000000..36a4d6d1
--- /dev/null
+++ b/Gemfile
@@ -0,0 +1,20 @@
+# Copyright 2020 Google, LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+source "https://rubygems.org"
+
+group :development, :test do
+  gem "google-style", "~> 1.24.0"
+  gem "rake", "~> 13.0"
+end
diff --git a/Rakefile b/Rakefile
new file mode 100644
index 00000000..1c57de59
--- /dev/null
+++ b/Rakefile
@@ -0,0 +1,128 @@
+require "json"
+require "rake"
+require "open3"
+require "timeout"
+
+task :test do
+  run_tests local: true
+end
+
+task :acceptance do
+  run_tests local: true, acceptance: true
+end
+
+namespace :kokoro do
+  task :presubmit do
+    run_tests
+  end
+
+  task :continuous do
+    run_tests
+  end
+
+  task :post do
+    require_relative "rakelib/link_checker.rb"
+
+    link_checker = LinkChecker.new
+    link_checker.run
+    exit link_checker.exit_status
+  end
+end
+
+def header str, token = "#"
+  line_length = str.length + 8
+  puts ""
+  puts token * line_length
+  puts "#{token * 3} #{str} #{token * 3}"
+  puts token * line_length
+  puts ""
+end
+
+def header_2 str, token = "#"
+  puts "\n#{token * 3} #{str} #{token * 3}\n"
+end
+
+def each_sample
+  gemfiles = Dir.glob("**/Gemfile") - ["Gemfile"]
+  gemfiles.map! { |gemfile| File.dirname gemfile }.uniq!
+  gemfiles.each do |dir|
+    yield dir
+  end
+end
+
+def load_env_vars
+  service_account = "#{ENV['KOKORO_GFILE_DIR']}/service-account.json"
+  raise "#{service_account} is not a file" unless File.file? service_account
+  ENV["GOOGLE_APPLICATION_CREDENTIALS"] = service_account
+  filename = "#{ENV['KOKORO_GFILE_DIR']}/env_vars.json"
+  raise "#{filename} is not a file" unless File.file? filename
+  env_vars = JSON.parse File.read(filename)
+  env_vars.each { |k, v| ENV[k] = v }
+end
+
+def job_info sample = nil
+  header "Using Ruby - #{RUBY_VERSION}"
+  header_2 "Job Type: #{ENV['JOB_TYPE']}"
+  header_2 "Sample: #{sample}"
+  puts ""
+end
+
+def run_tests acceptance: false, local: false
+  failed = false
+  failed = true if run "bundle exec rubocop"
+  Dir.chdir "sessions" do
+    Bundler.with_clean_env do
+      job_info "sessions"
+      failed = true if run "bundle update"
+      load_env_vars unless local
+      failed = true if run "bundle exec rake test"
+      if acceptance
+        failed = true if run "bundle exec rake acceptance", 1800
+      end
+    end
+  end
+  exit failed ? 1 : 0 unless acceptance
+  Dir.chdir "bookshelf" do
+    Bundler.with_clean_env do
+      job_info "bookshelf"
+      failed = true if run "wget -q https://storage.googleapis.com/gcd/tools/cloud-datastore-emulator-1.1.1.zip -O cloud-datastore-emulator.zip"
+      failed = true if run "unzip -o cloud-datastore-emulator.zip"
+
+      failed = true if run "cloud-datastore-emulator/cloud_datastore_emulator create gcd-test-dataset-directory"
+      failed = true if run "cloud-datastore-emulator/cloud_datastore_emulator start --testing ./gcd-test-dataset-directory/ &"
+
+      failed = true if run "RAILS_ENV=test bundle exec rake --rakefile=Rakefile assets:precompile"
+      failed = true if run "bundle update"
+      load_env_vars unless local
+      failed = true if run "bundle exec rspec"
+    end
+  end
+  exit failed ? 1 : 0
+end
+
+def run command, timeout = 0
+  if timeout.positive?
+    run_command_with_timeout command, timeout
+  else
+    run_command command
+  end
+end
+
+def run_command command
+  out, err, st = Open3.capture3 command
+  puts out
+  if st.to_i != 0
+    puts err
+    return true
+  end
+  false
+end
+
+def run_command_with_timeout command, timeout
+  Timeout.timeout timeout do
+    return run_command command
+  end
+rescue Timeout::Error
+  header_2 "TIMEOUT - #{timeout / 60} minute limit exceeded."
+  true
+end
diff --git a/authenticating-users/Gemfile b/authenticating-users/Gemfile
index d0e716d6..ffacdd89 100644
--- a/authenticating-users/Gemfile
+++ b/authenticating-users/Gemfile
@@ -2,7 +2,7 @@
 
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
+git_source(:github) { |repo_name| "https://github.com/#{repo_name}" }
 
 # [START getting_started_requirements]
 gem "jwt", "~> 2.2"
diff --git a/authenticating-users/app.rb b/authenticating-users/app.rb
index 7b4d21a7..6ac55c99 100644
--- a/authenticating-users/app.rb
+++ b/authenticating-users/app.rb
@@ -61,8 +61,7 @@ def validate_assertion assertion
   key_id = JSON.parse(a_header)["kid"]
   cert = OpenSSL::PKey::EC.new settings.certificates[key_id]
   info = JWT.decode assertion, cert, true, algorithm: "ES256", audience: settings.audience
-  return info[0]["email"], info[0]["sub"]
-
+  [info[0]["email"], info[0]["sub"]]
 rescue StandardError => e
   puts "Failed to validate assertion: #{e}"
   [nil, nil]
diff --git a/bookshelf/Gemfile b/bookshelf/Gemfile
index 78779992..f371cc0c 100644
--- a/bookshelf/Gemfile
+++ b/bookshelf/Gemfile
@@ -14,36 +14,36 @@
 source "https://rubygems.org"
 git_source(:github) { |repo| "https://github.com/#{repo}.git" }
 
-ruby '>= 2.5'
+ruby ">= 2.5"
 
 # Bundle edge Rails instead: gem 'rails', github: 'rails/rails'
-gem 'rails', '~> 5.2.3'
+gem "google-cloud-error_reporting"
 gem "google-cloud-firestore", "~> 1.0"
 gem "google-cloud-storage", "~> 1.10"
-gem "google-cloud-error_reporting"
+gem "rails", "~> 5.2.3"
 
 gem "jquery-rails"
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console
-  gem 'byebug', platforms: [:mri, :mingw, :x64_mingw]
+  gem "byebug", platforms: [:mri, :mingw, :x64_mingw]
 end
 
 group :development do
   # Access an interactive console on exception pages or by calling 'console' anywhere in the code.
-  gem 'web-console', '>= 3.3.0'
-  gem 'listen', '>= 3.0.5', '< 3.2'
+  gem "listen", ">= 3.0.5", "< 3.2"
+  gem "web-console", ">= 3.3.0"
 end
 
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
-gem 'tzinfo-data', platforms: [:mingw, :mswin, :x64_mingw, :jruby]
+gem "tzinfo-data", platforms: [:mingw, :mswin, :x64_mingw, :jruby]
 
 group :test do
-  gem "rspec-rails"
-  gem "rspec-retry"
-  gem "rack-test"
   gem "capybara"
+  gem "phantomjs", require: "phantomjs/poltergeist"
   gem "poltergeist"
-  gem 'phantomjs', :require => 'phantomjs/poltergeist'
+  gem "rack-test"
+  gem "rspec-rails"
+  gem "rspec-retry"
 end
diff --git a/bookshelf/Rakefile b/bookshelf/Rakefile
index 3c82c54c..95cac7f1 100644
--- a/bookshelf/Rakefile
+++ b/bookshelf/Rakefile
@@ -14,6 +14,6 @@
 # Add your own tasks in files placed in lib/tasks ending in .rake,
 # for example lib/tasks/capistrano.rake, and they will automatically be available to Rake.
 
-require_relative 'config/application'
+require_relative "config/application"
 
 Rails.application.load_tasks
diff --git a/bookshelf/app/controllers/books_controller.rb b/bookshelf/app/controllers/books_controller.rb
index e87fd7cc..1dab4fa3 100644
--- a/bookshelf/app/controllers/books_controller.rb
+++ b/bookshelf/app/controllers/books_controller.rb
@@ -12,7 +12,6 @@
 # limitations under the License.
 
 class BooksController < ApplicationController
-
   PER_PAGE = 10
 
   def index
@@ -66,5 +65,4 @@ def book_params
     params.require(:book).permit :title, :author, :published_on, :description,
                                  :cover_image
   end
-
 end
diff --git a/bookshelf/app/controllers/stackdriver_controller.rb b/bookshelf/app/controllers/stackdriver_controller.rb
index 279fd30a..d4c36ded 100644
--- a/bookshelf/app/controllers/stackdriver_controller.rb
+++ b/bookshelf/app/controllers/stackdriver_controller.rb
@@ -13,7 +13,7 @@
 
 class StackdriverController < ApplicationController
   def logs
-    Rails.logger.add(Logger::INFO, "Hey, you triggered a custom log entry. Good job!")
+    Rails.logger.add Logger::INFO, "Hey, you triggered a custom log entry. Good job!"
     redirect_to "/books", flash: { success: "Log message sent" }
   end
 
diff --git a/bookshelf/app/models/book.rb b/bookshelf/app/models/book.rb
index 85aabdf7..8d82a6d9 100644
--- a/bookshelf/app/models/book.rb
+++ b/bookshelf/app/models/book.rb
@@ -11,6 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# rubocop:disable Metrics/ClassLength
 class Book
   # Add Active Model support.
   # Provides constructor that takes a Hash of attribute values.
@@ -45,7 +46,7 @@ def self.storage_bucket
       # [START bookshelf_cloud_storage_client]
       require "google/cloud/storage"
       bucket_id = project_id + "_bucket"
-      storage = Google::Cloud::Storage.new project_id: config["project_id"],
+      storage = Google::Cloud::Storage.new project_id:  config["project_id"],
                                            credentials: config["keyfile"]
       bucket = storage.bucket bucket_id
       # [END bookshelf_cloud_storage_client]
@@ -64,11 +65,8 @@ def self.query options = {}
     query = query.start_after options[:last_title] if options[:last_title]
 
     books = []
-    begin
-      query.get do |book|
-        books << Book.from_snapspot(book)
-      end
-    rescue
+    query.get do |book|
+      books << Book.from_snapspot(book)
     end
     books
   end
@@ -79,7 +77,7 @@ def self.requires_pagination last_title
         .order(:title)
         .limit(1)
         .start_after(last_title)
-        .get.count > 0
+        .get.count.positive?
     end
   end
 
@@ -142,14 +140,14 @@ def upload_image
       cover_image.tempfile,
       "cover_images/#{id}/#{cover_image.original_filename}",
       content_type: cover_image.content_type,
-      acl: "public"
+      acl:          "public"
     @image_url = file.public_url
   end
 
   def destroy
     delete_image if image_url
     book_ref = Book.collection.doc id
-    book_ref.delete if book_ref
+    book_ref&.delete
   end
 
   def delete_image
@@ -165,9 +163,10 @@ def delete_image
     end
   end
 
-##################
+  ##################
 
   def persisted?
     id.present?
   end
 end
+# rubocop:enable Metrics/ClassLength
diff --git a/bookshelf/bin/bundle b/bookshelf/bin/bundle
index f0160ef3..733a1433 100755
--- a/bookshelf/bin/bundle
+++ b/bookshelf/bin/bundle
@@ -13,5 +13,5 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
-load Gem.bin_path('bundler', 'bundle')
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path "../Gemfile", __dir__
+load Gem.bin_path("bundler", "bundle")
diff --git a/bookshelf/bin/rails b/bookshelf/bin/rails
index 9ce2e125..a66d698c 100755
--- a/bookshelf/bin/rails
+++ b/bookshelf/bin/rails
@@ -13,6 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-APP_PATH = File.expand_path('../config/application', __dir__)
-require_relative '../config/boot'
-require 'rails/commands'
+APP_PATH = File.expand_path "../config/application", __dir__
+require_relative "../config/boot"
+require "rails/commands"
diff --git a/bookshelf/bin/rake b/bookshelf/bin/rake
index b5a09919..57ef663c 100755
--- a/bookshelf/bin/rake
+++ b/bookshelf/bin/rake
@@ -13,6 +13,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-require_relative '../config/boot'
-require 'rake'
+require_relative "../config/boot"
+require "rake"
 Rake.application.run
diff --git a/bookshelf/bin/setup b/bookshelf/bin/setup
index a6e0ff37..1d2c5929 100755
--- a/bookshelf/bin/setup
+++ b/bookshelf/bin/setup
@@ -13,13 +13,13 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-require 'fileutils'
+require "fileutils"
 include FileUtils
 
 # path to your application root.
-APP_ROOT = File.expand_path('..', __dir__)
+APP_ROOT = File.expand_path "..", __dir__
 
-def system!(*args)
+def system! *args
   system(*args) || abort("\n== Command #{args} failed ==")
 end
 
@@ -27,9 +27,9 @@ chdir APP_ROOT do
   # This script is a starting point to setup your application.
   # Add necessary setup steps to this file.
 
-  puts '== Installing dependencies =='
-  system! 'gem install bundler --conservative'
-  system('bundle check') || system!('bundle install')
+  puts "== Installing dependencies =="
+  system! "gem install bundler --conservative"
+  system("bundle check") || system!("bundle install")
 
   # puts "\n== Copying sample files =="
   # unless File.exist?('config/database.yml')
@@ -37,11 +37,11 @@ chdir APP_ROOT do
   # end
 
   puts "\n== Preparing database =="
-  system! 'bin/rails db:setup'
+  system! "bin/rails db:setup"
 
   puts "\n== Removing old logs and tempfiles =="
-  system! 'bin/rails log:clear tmp:clear'
+  system! "bin/rails log:clear tmp:clear"
 
   puts "\n== Restarting application server =="
-  system! 'bin/rails restart'
+  system! "bin/rails restart"
 end
diff --git a/bookshelf/config.ru b/bookshelf/config.ru
index e8150033..6807d6b9 100644
--- a/bookshelf/config.ru
+++ b/bookshelf/config.ru
@@ -13,6 +13,6 @@
 
 # This file is used by Rack-based servers to start the application.
 
-require_relative 'config/environment'
+require_relative "config/environment"
 
 run Rails.application
diff --git a/bookshelf/config/application.rb b/bookshelf/config/application.rb
index 8fbe6a48..c5e57745 100644
--- a/bookshelf/config/application.rb
+++ b/bookshelf/config/application.rb
@@ -11,7 +11,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-require_relative 'boot'
+require_relative "boot"
 
 require "rails"
 # Pick the frameworks you want:
diff --git a/bookshelf/config/boot.rb b/bookshelf/config/boot.rb
index 122835d2..c9a65abb 100644
--- a/bookshelf/config/boot.rb
+++ b/bookshelf/config/boot.rb
@@ -11,6 +11,6 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ENV['BUNDLE_GEMFILE'] ||= File.expand_path('../Gemfile', __dir__)
+ENV["BUNDLE_GEMFILE"] ||= File.expand_path "../Gemfile", __dir__
 
-require 'bundler/setup' # Set up gems listed in the Gemfile.
+require "bundler/setup" # Set up gems listed in the Gemfile.
diff --git a/bookshelf/config/environment.rb b/bookshelf/config/environment.rb
index 49506954..47af2ed8 100644
--- a/bookshelf/config/environment.rb
+++ b/bookshelf/config/environment.rb
@@ -12,7 +12,7 @@
 # limitations under the License.
 
 # Load the Rails application.
-require_relative 'application'
+require_relative "application"
 
 # Initialize the Rails application.
 Rails.application.initialize!
diff --git a/bookshelf/config/environments/development.rb b/bookshelf/config/environments/development.rb
index d381801e..21eab417 100644
--- a/bookshelf/config/environments/development.rb
+++ b/bookshelf/config/environments/development.rb
@@ -27,12 +27,12 @@
 
   # Enable/disable caching. By default caching is disabled.
   # Run rails dev:cache to toggle caching.
-  if Rails.root.join('tmp', 'caching-dev.txt').exist?
+  if Rails.root.join("tmp", "caching-dev.txt").exist?
     config.action_controller.perform_caching = true
 
     config.cache_store = :memory_store
     config.public_file_server.headers = {
-      'Cache-Control' => "public, max-age=#{2.days.to_i}"
+      "Cache-Control" => "public, max-age=#{2.days.to_i}"
     }
   else
     config.action_controller.perform_caching = false
diff --git a/bookshelf/config/environments/production.rb b/bookshelf/config/environments/production.rb
index 4bc53ce0..b0e54a17 100644
--- a/bookshelf/config/environments/production.rb
+++ b/bookshelf/config/environments/production.rb
@@ -33,7 +33,7 @@
 
   # Disable serving static files from the `/public` folder by default since
   # Apache or NGINX already handles this.
-  config.public_file_server.enabled = ENV['RAILS_SERVE_STATIC_FILES'].present?
+  config.public_file_server.enabled = ENV["RAILS_SERVE_STATIC_FILES"].present?
 
   # Enable serving of images, stylesheets, and JavaScripts from an asset server.
   # config.action_controller.asset_host = 'http://assets.example.com'
@@ -58,7 +58,7 @@
   config.log_level = :debug
 
   # Prepend all log lines with the following tags.
-  config.log_tags = [ :request_id ]
+  config.log_tags = [:request_id]
 
   # Use a different cache store in production.
   # config.cache_store = :mem_cache_store
@@ -88,9 +88,9 @@
   # config.logger = ActiveSupport::TaggedLogging.new(Syslog::Logger.new 'app-name')
 
   if ENV["RAILS_LOG_TO_STDOUT"].present?
-    logger           = ActiveSupport::Logger.new(STDOUT)
+    logger           = ActiveSupport::Logger.new STDOUT
     logger.formatter = config.log_formatter
-    config.logger    = ActiveSupport::TaggedLogging.new(logger)
+    config.logger    = ActiveSupport::TaggedLogging.new logger
   end
 
   # Do not dump schema after migrations.
diff --git a/bookshelf/config/environments/test.rb b/bookshelf/config/environments/test.rb
index e43533e9..35e28bdb 100644
--- a/bookshelf/config/environments/test.rb
+++ b/bookshelf/config/environments/test.rb
@@ -28,7 +28,7 @@
   # Configure public file server for tests with Cache-Control for performance.
   config.public_file_server.enabled = true
   config.public_file_server.headers = {
-    'Cache-Control' => "public, max-age=#{1.hour.to_i}"
+    "Cache-Control" => "public, max-age=#{1.hour.to_i}"
   }
 
   # Show full error reports and disable caching.
diff --git a/bookshelf/config/initializers/session_store.rb b/bookshelf/config/initializers/session_store.rb
index dc6bbade..b277a3f7 100644
--- a/bookshelf/config/initializers/session_store.rb
+++ b/bookshelf/config/initializers/session_store.rb
@@ -13,4 +13,4 @@
 
 # Be sure to restart your server when you modify this file.
 
-Rails.application.config.session_store :cookie_store, key: '_Bookshelf_session'
+Rails.application.config.session_store :cookie_store, key: "_Bookshelf_session"
diff --git a/bookshelf/config/initializers/wrap_parameters.rb b/bookshelf/config/initializers/wrap_parameters.rb
index dc9d176a..41341fd7 100644
--- a/bookshelf/config/initializers/wrap_parameters.rb
+++ b/bookshelf/config/initializers/wrap_parameters.rb
@@ -17,7 +17,7 @@
 # is enabled by default.
 
 # Enable parameter wrapping for JSON. You can disable this by setting :format to an empty array.
-ActiveSupport.on_load(:action_controller) do
+ActiveSupport.on_load :action_controller do
   wrap_parameters format: [:json]
 end
 
diff --git a/bookshelf/config/routes.rb b/bookshelf/config/routes.rb
index be9781b9..b63e78b8 100644
--- a/bookshelf/config/routes.rb
+++ b/bookshelf/config/routes.rb
@@ -12,7 +12,6 @@
 # limitations under the License.
 
 Rails.application.routes.draw do
-
   # Route root of application to BooksController#index action
   root "books#index"
 
@@ -21,5 +20,4 @@
 
   get "/logs", to: "stackdriver#logs"
   get "/errors", to: "stackdriver#errors"
-
 end
diff --git a/gce/Gemfile b/gce/Gemfile
index cc0b14e2..91d27464 100644
--- a/gce/Gemfile
+++ b/gce/Gemfile
@@ -2,6 +2,4 @@
 
 source "https://rubygems.org"
 
-git_source(:github) {|repo_name| "https://github.com/#{repo_name}" }
-
 gem "sinatra", "~> 2.0"
diff --git a/rakelib/link_checker.rb b/rakelib/link_checker.rb
new file mode 100644
index 00000000..d1b5f49f
--- /dev/null
+++ b/rakelib/link_checker.rb
@@ -0,0 +1,64 @@
+require "open3"
+
+class LinkChecker
+  def initialize
+    @failed = false
+  end
+
+  def run
+    job_info
+    git_commit = ENV.fetch "KOKORO_GITHUB_COMMIT", "master"
+
+    markdown_files = Dir.glob "**/*.md"
+    broken_markdown_links = check_links markdown_files,
+                                        "https://github.com/googleapis/signet/tree/#{git_commit}",
+                                        " --skip '^(?!(\\Wruby.*google|.*google.*\\Wruby|.*cloud\\.google\\.com))'"
+
+    broken_devsite_links = check_links ["signet"],
+                                       "https://googleapis.dev/ruby",
+                                       "/latest/ --recurse --skip https:.*github.*"
+
+    puts_broken_links broken_markdown_links
+    puts_broken_links broken_devsite_links
+  end
+
+  def check_links location_list, base, tail
+    broken_links = Hash.new { |h, k| h[k] = [] }
+    location_list.each do |location|
+      out, err, st = Open3.capture3 "npx linkinator #{base}/#{location}#{tail}"
+      puts out
+      unless st.to_i.zero?
+        @failed = true
+        puts err
+      end
+      checked_links = out.split "\n"
+      checked_links.select! { |link| link =~ /\[\d+\]/ && !link.include?("[200]") }
+      unless checked_links.empty?
+        @failed = true
+        broken_links[location] += checked_links
+      end
+    end
+    broken_links
+  end
+
+  def puts_broken_links link_hash
+    link_hash.each do |location, links|
+      puts "#{location} contains the following broken links:"
+      links.each { |link| puts "  #{link}" }
+      puts
+    end
+  end
+
+  def job_info
+    line_length = "Using Ruby - #{RUBY_VERSION}".length + 8
+    puts
+    puts "#" * line_length
+    puts "### Using Ruby - #{RUBY_VERSION} ###"
+    puts "#" * line_length
+    puts
+  end
+
+  def exit_status
+    @failed ? 1 : 0
+  end
+end
diff --git a/sessions/acceptance/app_test.rb b/sessions/acceptance/app_test.rb
index 5dc39fd6..1877c6ba 100644
--- a/sessions/acceptance/app_test.rb
+++ b/sessions/acceptance/app_test.rb
@@ -1,4 +1,4 @@
-require File.expand_path "../../test/test_helper.rb", __FILE__
+require File.expand_path "../test/test_helper.rb", __dir__
 
 include Rack::Test::Methods
 
@@ -7,15 +7,15 @@ def app
 end
 
 def firestore
-  firestore = Google::Cloud::Firestore.new
+  Google::Cloud::Firestore.new
 end
 
 def col
-  col = firestore.col "sessions"
+  firestore.col "sessions"
 end
 
 def docs
-  docs = col.list_documents
+  col.list_documents
 end
 
 def delete_all_sessions
@@ -37,7 +37,7 @@ def delete_all_sessions
 
   it "should display the number of views" do
     get "/"
-    assert_match /\d+ views for /, last_response.body
+    assert_match(/\d+ views for /, last_response.body)
   end
 
   it "should increment the number of views on successive views" do
diff --git a/sessions/test/app_test.rb b/sessions/test/app_test.rb
index f7f57967..651ea9d8 100644
--- a/sessions/test/app_test.rb
+++ b/sessions/test/app_test.rb
@@ -1,4 +1,4 @@
-require File.expand_path "../test_helper.rb", __FILE__
+require File.expand_path "test_helper.rb", __dir__
 
 include Rack::Test::Methods
 
@@ -14,7 +14,7 @@ def initialize app, options = {}
 
   def find_session _req, session_id
     return [generate_sid, {}] if session_id.nil?
-    return session_id, @data[session_id]
+    [session_id, @data[session_id]]
   end
 
   def write_session _req, session_id, new_session, _opts
@@ -30,7 +30,7 @@ def delete_session _req, session_id, _opts
 
 describe "app" do
   before do
-    @mock_session = lambda do |app, options = {}| 
+    @mock_session = lambda do |app, _options = {}|
       FirestoreSessionMock.new app, {}
     end
   end
@@ -41,13 +41,12 @@ def delete_session _req, session_id, _opts
       greetings = /"Hello World"|"Hallo Welt"|"Ciao Mondo"|"Salut le Monde"|"Hola Mundo"/
       assert_match greetings, last_response.body
     end
-    
   end
 
   it "should display the number of views" do
     Rack::Session::FirestoreSession.stub :new, @mock_session do
       get "/"
-      assert_match /\d+ views for /, last_response.body
+      assert_match(/\d+ views for /, last_response.body)
     end
   end
 
diff --git a/sessions/test/test_helper.rb b/sessions/test/test_helper.rb
index 9a71cf16..1e6d564a 100644
--- a/sessions/test/test_helper.rb
+++ b/sessions/test/test_helper.rb
@@ -2,4 +2,4 @@
 require "minitest/autorun"
 require "rack/test"
 
-require File.expand_path "../../app.rb", __FILE__
+require File.expand_path "../app.rb", __dir__