Fix rails restart issue with Puma

- We need to pass the restart command to Puma so that it will use it
  while restarting the server.
- Also made sure that all the options passed by user while starting
  the server are used in the generated restart command so that they will
  be used while restarting the server.
- Besides that we need to remove the server.pid file for the previous running
  server because otherwise Rack complains about it's presence.
- We don't care if the server.pid file does not exist. We only want to delete
  it if it exists.
- This also requires some changes on Puma side which are being tracked
  here - https://github.com/puma/puma/pull/936.
- Fixes #23910.

7 files changed, 45 insertions, 1 deletions

diff --git a/railties/CHANGELOG.md b/railties/CHANGELOG.md
index 7193238e83..52c2e0743c 100644
--- a/railties/CHANGELOG.md
+++ b/railties/CHANGELOG.md
@@ -1,3 +1,8 @@
+*   Make `rails restart` command work with Puma by passing the restart command
+    which Puma can use to restart rails server.
+
+    *Prathamesh Sonpatki*
+
 *   The application generator writes a new file `config/spring.rb`, which tells
     Spring to watch additional common files.
 
diff --git a/railties/lib/rails/commands/server.rb b/railties/lib/rails/commands/server.rb
index c2434d62e2..7418dff18b 100644
--- a/railties/lib/rails/commands/server.rb
+++ b/railties/lib/rails/commands/server.rb
@@ -94,7 +94,8 @@ module Rails
         environment:        (ENV['RAILS_ENV'] || ENV['RACK_ENV'] || "development").dup,
         daemonize:          false,
         caching:            nil,
-        pid:                Options::DEFAULT_PID_PATH
+        pid:                Options::DEFAULT_PID_PATH,
+        restart_cmd:        restart_command
       })
     end
 
@@ -130,5 +131,9 @@ module Rails
           Rails.logger.extend(ActiveSupport::Logger.broadcast(console))
         end
       end
+
+      def restart_command
+        "bin/rails server #{ARGV.join(' ')}"
+      end
   end
 end
diff --git a/railties/lib/rails/dev_caching.rb b/railties/lib/rails/dev_caching.rb
index 4760010851..3c20164f0f 100644
--- a/railties/lib/rails/dev_caching.rb
+++ b/railties/lib/rails/dev_caching.rb
@@ -15,6 +15,7 @@ module Rails
         end
 
         FileUtils.touch 'tmp/restart.txt'
+        FileUtils.rm_f('tmp/pids/server.pid')
       end
 
       def enable_by_argument(caching)
diff --git a/railties/lib/rails/tasks/restart.rake b/railties/lib/rails/tasks/restart.rake
index f36c86d81b..7e15bb55a1 100644
--- a/railties/lib/rails/tasks/restart.rake
+++ b/railties/lib/rails/tasks/restart.rake
@@ -2,4 +2,5 @@ desc "Restart app by touching tmp/restart.txt"
 task :restart do
   FileUtils.mkdir_p('tmp')
   FileUtils.touch('tmp/restart.txt')
+  FileUtils.rm_f('tmp/pids/server.pid')
 end
diff --git a/railties/test/application/rake/dev_test.rb b/railties/test/application/rake/dev_test.rb
index 59b46c6e79..deb9bc8dee 100644
--- a/railties/test/application/rake/dev_test.rb
+++ b/railties/test/application/rake/dev_test.rb
@@ -29,6 +29,15 @@ module ApplicationTests
           assert_match(/Development mode is no longer being cached/, output)
         end
       end
+
+      test 'dev:cache removes server.pid also' do
+        Dir.chdir(app_path) do
+          FileUtils.mkdir_p("tmp/pids")
+          FileUtils.touch("tmp/pids/server.pid")
+          `rake dev:cache`
+          assert_not File.exist?("tmp/pids/server.pid")
+        end
+      end
     end
   end
 end
diff --git a/railties/test/application/rake/restart_test.rb b/railties/test/application/rake/restart_test.rb
index 4cae199e6b..30f662a9be 100644
--- a/railties/test/application/rake/restart_test.rb
+++ b/railties/test/application/rake/restart_test.rb
@@ -34,6 +34,15 @@ module ApplicationTests
           assert File.exist?('tmp/restart.txt')
         end
       end
+
+      test 'rake restart removes server.pid also' do
+        Dir.chdir(app_path) do
+          FileUtils.mkdir_p("tmp/pids")
+          FileUtils.touch("tmp/pids/server.pid")
+          `rake restart`
+          assert_not File.exist?("tmp/pids/server.pid")
+        end
+      end
     end
   end
 end
diff --git a/railties/test/commands/server_test.rb b/railties/test/commands/server_test.rb
index 964b9a44de..38a1605d1f 100644
--- a/railties/test/commands/server_test.rb
+++ b/railties/test/commands/server_test.rb
@@ -118,4 +118,18 @@ class Rails::ServerTest < ActiveSupport::TestCase
       assert_equal old_default_options, server.default_options
     end
   end
+
+  def test_restart_command_contains_customized_options
+    original_args = ARGV.dup
+    args = ["-p", "4567"]
+    ARGV.replace args
+
+    options = Rails::Server::Options.new.parse! args
+    server = Rails::Server.new options
+    expected = "bin/rails server -p 4567"
+
+    assert_equal expected, server.default_options[:restart_cmd]
+  ensure
+    ARGV.replace original_args
+  end
 end