diff --git a/Rakefile b/Rakefile
index 12ac12710fb..cc02aa130ab 100755
--- a/Rakefile
+++ b/Rakefile
@@ -12,7 +12,8 @@ load 'tools/distrib/docker_for_windows.rb'
 # Add rubocop style checking tasks
 RuboCop::RakeTask.new(:rubocop) do |task|
   task.options = ['-c', 'src/ruby/.rubocop.yml']
-  task.patterns = ['src/ruby/{lib,spec}/**/*.rb']
+  # add end2end tests to formatter but don't add generated proto _pb.rb's
+  task.patterns = ['src/ruby/{lib,spec}/**/*.rb', 'src/ruby/end2end/*.rb']
 end
 
 spec = Gem::Specification.load('grpc.gemspec')
diff --git a/src/ruby/.rubocop.yml b/src/ruby/.rubocop.yml
index 0f61ccfa812..7174f3b15af 100644
--- a/src/ruby/.rubocop.yml
+++ b/src/ruby/.rubocop.yml
@@ -9,6 +9,7 @@ AllCops:
     - 'bin/math_services_pb.rb'
     - 'pb/grpc/health/v1/*'
     - 'pb/test/**/*'
+    - 'end2end/lib/*'
 
 Metrics/CyclomaticComplexity:
   Max: 9
diff --git a/src/ruby/end2end/channel_closing_client.rb b/src/ruby/end2end/channel_closing_client.rb
index a9df0784217..84497973607 100755
--- a/src/ruby/end2end/channel_closing_client.rb
+++ b/src/ruby/end2end/channel_closing_client.rb
@@ -31,10 +31,13 @@
 
 require_relative './end2end_common'
 
+# Calls '#close' on a Channel when "shutdown" called. This tries to
+# trigger a hang or crash bug by closing a channel actively being watched
 class ChannelClosingClientController < ClientControl::ClientController::Service
   def initialize(ch)
     @ch = ch
   end
+
   def shutdown(_, _)
     @ch.close
     ClientControl::Void.new
@@ -53,7 +56,8 @@ def main
     end
   end.parse!
 
-  ch = GRPC::Core::Channel.new("localhost:#{server_port}", {}, :this_channel_is_insecure)
+  ch = GRPC::Core::Channel.new("localhost:#{server_port}", {},
+                               :this_channel_is_insecure)
 
   srv = GRPC::RpcServer.new
   thd = Thread.new do
diff --git a/src/ruby/end2end/channel_closing_driver.rb b/src/ruby/end2end/channel_closing_driver.rb
index 98c8eaa1cdf..43e2fe8cbbd 100755
--- a/src/ruby/end2end/channel_closing_driver.rb
+++ b/src/ruby/end2end/channel_closing_driver.rb
@@ -29,23 +29,24 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-# make sure that the client doesn't hang when channel is closed explictly while it's used
+# make sure that the client doesn't hang when channel is closed
+# explictly while it's used
 
 require_relative './end2end_common'
 
 def main
-  STDERR.puts "start server"
+  STDERR.puts 'start server'
   server_runner = ServerRunner.new
   server_port = server_runner.run
 
   sleep 1
 
-  STDERR.puts "start client"
-  control_stub, client_pid = start_client("channel_closing_client.rb", server_port)
+  STDERR.puts 'start client'
+  control_stub, client_pid = start_client('channel_closing_client.rb',
+                                          server_port)
 
   sleep 3
 
-
   begin
     Timeout.timeout(10) do
       control_stub.shutdown(ClientControl::Void.new)
@@ -55,8 +56,9 @@ def main
     STDERR.puts "timeout wait for client pid #{client_pid}"
     Process.kill('SIGKILL', client_pid)
     Process.wait(client_pid)
-    STDERR.puts "killed client child"
-    raise 'Timed out waiting for client process. It likely hangs when a channel is closed while connectivity is watched'
+    STDERR.puts 'killed client child'
+    raise 'Timed out waiting for client process. It likely hangs when a ' \
+      'channel is closed while connectivity is watched'
   end
 
   server_runner.stop
diff --git a/src/ruby/end2end/channel_state_client.rb b/src/ruby/end2end/channel_state_client.rb
index 476329ff73a..08c21bbb8e8 100755
--- a/src/ruby/end2end/channel_state_client.rb
+++ b/src/ruby/end2end/channel_state_client.rb
@@ -34,15 +34,16 @@ require_relative './end2end_common'
 def main
   server_port = ''
   OptionParser.new do |opts|
-    opts.on('--client_control_port=P', String) do |p|
-      STDERR.puts "client_control_port ignored"
+    opts.on('--client_control_port=P', String) do
+      STDERR.puts 'client_control_port ignored'
     end
     opts.on('--server_port=P', String) do |p|
       server_port = p
     end
   end.parse!
 
-  ch = GRPC::Core::Channel.new("localhost:#{server_port}", {}, :this_channel_is_insecure)
+  ch = GRPC::Core::Channel.new("localhost:#{server_port}", {},
+                               :this_channel_is_insecure)
 
   loop do
     state = ch.connectivity_state
diff --git a/src/ruby/end2end/channel_state_driver.rb b/src/ruby/end2end/channel_state_driver.rb
index 8ef32acfffe..c3184bf9392 100755
--- a/src/ruby/end2end/channel_state_driver.rb
+++ b/src/ruby/end2end/channel_state_driver.rb
@@ -34,14 +34,14 @@
 require_relative './end2end_common'
 
 def main
-  STDERR.puts "start server"
+  STDERR.puts 'start server'
   server_runner = ServerRunner.new
   server_port = server_runner.run
 
   sleep 1
 
-  STDERR.puts "start client"
-  _, client_pid = start_client("channel_state_client.rb", server_port)
+  STDERR.puts 'start client'
+  _, client_pid = start_client('channel_state_client.rb', server_port)
 
   sleep 3
 
@@ -53,8 +53,9 @@ def main
     STDERR.puts "timeout wait for client pid #{client_pid}"
     Process.kill('SIGKILL', client_pid)
     Process.wait(client_pid)
-    STDERR.puts "killed client child"
-    raise 'Timed out waiting for client process. It likely hangs when ended abruptly'
+    STDERR.puts 'killed client child'
+    raise 'Timed out waiting for client process. ' \
+           'It likely hangs when ended abruptly'
   end
 
   server_runner.stop
diff --git a/src/ruby/end2end/end2end_common.rb b/src/ruby/end2end/end2end_common.rb
index d98e41f6421..9534bb20787 100755
--- a/src/ruby/end2end/end2end_common.rb
+++ b/src/ruby/end2end/end2end_common.rb
@@ -43,6 +43,7 @@ require 'socket'
 require 'optparse'
 require 'thread'
 require 'timeout'
+require 'English' # see https://github.com/bbatsov/rubocop/issues/1747
 
 # GreeterServer is simple server that implements the Helloworld Greeter server.
 class EchoServerImpl < Echo::EchoServer::Service
@@ -52,9 +53,11 @@ class EchoServerImpl < Echo::EchoServer::Service
   end
 end
 
+# ServerRunner starts an "echo server" that test clients can make calls to
 class ServerRunner
   def initialize
   end
+
   def run
     @srv = GRPC::RpcServer.new
     port = @srv.add_http2_port('0.0.0.0:0', :this_port_is_insecure)
@@ -66,10 +69,11 @@ class ServerRunner
     @srv.wait_till_running
     port
   end
+
   def stop
     @srv.stop
     @thd.join
-    raise "server not stopped" unless @srv.stopped?
+    fail 'server not stopped' unless @srv.stopped?
   end
 end
 
@@ -81,22 +85,24 @@ def start_client(client_main, server_port)
   tmp_server.close
 
   client_path = File.join(this_dir, client_main)
-  client_pid = Process.spawn(RbConfig.ruby, client_path,
-			     "--client_control_port=#{client_control_port}",
-			     "--server_port=#{server_port}")
+  client_pid = Process.spawn(RbConfig.ruby,
+                             client_path,
+                             "--client_control_port=#{client_control_port}",
+                             "--server_port=#{server_port}")
   sleep 1
-  control_stub = ClientControl::ClientController::Stub.new("localhost:#{client_control_port}", :this_channel_is_insecure)
-  return control_stub, client_pid
+  control_stub = ClientControl::ClientController::Stub.new(
+    "localhost:#{client_control_port}", :this_channel_is_insecure)
+  [control_stub, client_pid]
 end
 
 def cleanup(control_stub, client_pid, server_runner)
   control_stub.shutdown(ClientControl::Void.new)
   Process.wait(client_pid)
 
-  client_exit_code = $?.exitstatus
+  client_exit_code = $CHILD_STATUS
 
   if client_exit_code != 0
-    raise "term sig test failure: client exit code: #{client_exit_code}"
+    fail "term sig test failure: client exit code: #{client_exit_code}"
   end
 
   server_runner.stop
diff --git a/src/ruby/end2end/sig_handling_client.rb b/src/ruby/end2end/sig_handling_client.rb
index f0b2ba61caf..5b1e54718ec 100755
--- a/src/ruby/end2end/sig_handling_client.rb
+++ b/src/ruby/end2end/sig_handling_client.rb
@@ -31,20 +31,25 @@
 
 require_relative './end2end_common'
 
+# Test client. Sends RPC's as normal but process also has signal handlers
 class SigHandlingClientController < ClientControl::ClientController::Service
   def initialize(srv, stub)
     @srv = srv
     @stub = stub
   end
+
   def do_echo_rpc(req, _)
     response = @stub.echo(Echo::EchoRequest.new(request: req.request))
-    raise "bad response" unless response.response == req.request
+    fail 'bad response' unless response.response == req.request
     ClientControl::Void.new
   end
+
   def shutdown(_, _)
     Thread.new do
-      #TODO(apolcyn) There is a race between stopping the server and the "shutdown" rpc completing,
-      # See if stop method on server can end active RPC cleanly, to avoid this sleep.
+      # TODO(apolcyn) There is a race between stopping the
+      # server and the "shutdown" rpc completing,
+      # See if stop method on server can end active RPC cleanly, to
+      # avoid this sleep.
       sleep 3
       @srv.stop
     end
@@ -64,17 +69,19 @@ def main
     end
   end.parse!
 
-  Signal.trap("TERM") do
-    STDERR.puts "SIGTERM received"
+  Signal.trap('TERM') do
+    STDERR.puts 'SIGTERM received'
   end
 
-  Signal.trap("INT") do
-    STDERR.puts "SIGINT received"
+  Signal.trap('INT') do
+    STDERR.puts 'SIGINT received'
   end
 
   srv = GRPC::RpcServer.new
-  srv.add_http2_port("0.0.0.0:#{client_control_port}", :this_port_is_insecure)
-  stub = Echo::EchoServer::Stub.new("localhost:#{server_port}", :this_channel_is_insecure)
+  srv.add_http2_port("0.0.0.0:#{client_control_port}",
+                     :this_port_is_insecure)
+  stub = Echo::EchoServer::Stub.new("localhost:#{server_port}",
+                                    :this_channel_is_insecure)
   srv.handle(SigHandlingClientController.new(srv, stub))
   srv.run
 end
diff --git a/src/ruby/end2end/sig_handling_driver.rb b/src/ruby/end2end/sig_handling_driver.rb
index 4d205da9ae3..c5d46e074cb 100755
--- a/src/ruby/end2end/sig_handling_driver.rb
+++ b/src/ruby/end2end/sig_handling_driver.rb
@@ -35,20 +35,21 @@
 require_relative './end2end_common'
 
 def main
-  STDERR.puts "start server"
+  STDERR.puts 'start server'
   server_runner = ServerRunner.new
   server_port = server_runner.run
 
   sleep 1
 
-  STDERR.puts "start client"
-  control_stub, client_pid = start_client("sig_handling_client.rb", server_port)
+  STDERR.puts 'start client'
+  control_stub, client_pid = start_client('sig_handling_client.rb', server_port)
 
   sleep 1
 
   count = 0
   while count < 5
-    control_stub.do_echo_rpc(ClientControl::DoEchoRpcRequest.new(request: 'hello'))
+    control_stub.do_echo_rpc(
+      ClientControl::DoEchoRpcRequest.new(request: 'hello'))
     Process.kill('SIGTERM', client_pid)
     Process.kill('SIGINT', client_pid)
     count += 1