Added delayed puma shutdown gem and updated puma to use plugin

Author: davezuckerman

Gemfile

@@ -19,6 +19,7 @@ gem 'omniauth-cas', '3.0.0'
 gem 'omniauth-rails_csrf_protection', '~> 1.0'
 gem 'pg', '~> 1.4.6'
 gem 'puma', '~> 6.4.1'
+gem 'puma-plugin-delayed_stop', '~> 0.1.2'
 gem 'rack-timeout', '~> 0.6.3'
 gem 'rails', '~> 7.1.5'
 gem 'rsolr', '>= 1.0', '< 3'

Gemfile.lock

@@ -319,6 +319,8 @@ GEM
     public_suffix (6.0.1)
     puma (6.4.3)
       nio4r (~> 2.0)
+    puma-plugin-delayed_stop (0.1.2)
+      puma (>= 5.0, < 8)
     racc (1.8.1)
     rack (2.2.10)
     rack-protection (3.2.0)
@@ -552,6 +554,7 @@ DEPENDENCIES
   omniauth-rails_csrf_protection (~> 1.0)
   pg (~> 1.4.6)
   puma (~> 6.4.1)
+  puma-plugin-delayed_stop (~> 0.1.2)
   rack-timeout (~> 0.6.3)
   rails (~> 7.1.5)
   rsolr (>= 1.0, < 3)

config/puma.rb

@@ -36,3 +36,7 @@
 
 # Allow puma to be restarted by `bin/rails restart` command.
 plugin :tmp_restart
+
+# Adds a drain period during shutdown so swarm can elegantly remove it from
+# the routing mesh
+plugin :delayed_stop