Use SSL/TLS in development

See https://github.com/socketry/localhost/tree/v1.1.9/guides/browser-configuration

Uses the new integration in Puma: puma/puma#2610

.foreman

@@ -1 +1,2 @@
+formation: development=1
 port: 8080

Gemfile

@@ -27,6 +27,7 @@ gem 'pry'
 
 group :development do
   gem 'foreman'
+  gem 'localhost'
 end
 
 group :test do

Gemfile.lock

@@ -34,6 +34,7 @@ GEM
       domain_name (~> 0.5)
     i18n (1.8.10)
       concurrent-ruby (~> 1.0)
+    localhost (1.1.9)
     method_source (1.0.0)
     mime-types (3.3.1)
       mime-types-data (~> 3.2015)
@@ -145,6 +146,7 @@ DEPENDENCIES
   github-markup
   haml
   html-pipeline
+  localhost
   minitest
   octokit
   pg
@@ -170,4 +172,4 @@ RUBY VERSION
    ruby 2.6.8p205
 
 BUNDLED WITH
-   2.2.23
+   2.2.25

Procfile

@@ -1 +1,2 @@
 web: bundle exec puma -C config/puma.rb
+development: bundle exec puma -b tcp://localhost:$(($PORT-100)) -b ssl://localhost:$(($PORT-100-1000))

config.ru

@@ -16,8 +16,21 @@ end
 
 require_relative 'config/app'
 
-unless development? || test?
-  use Rack::SSL
+# SSL/TLS in development on port $PORT-1000 (port $PORT will redirect there)
+# https://github.com/socketry/localhost
+require 'localhost' if development?
+
+unless test?
+  options = if development?
+    # Subtract 100 because of foreman offset bug:
+    #   https://github.com/ddollar/foreman/issues/714
+    #   https://github.com/ddollar/foreman/issues/418
+    { host: "localhost:#{ENV.fetch('PORT').to_i - 100 - 1000}" }
+  else
+    {}
+  end
+
+  use Rack::SSL, options
 end
 
 use Rack::Session::Cookie,

test/integration/app_boot_test.rb

@@ -25,4 +25,18 @@ def test_app_boot
     WaitForIt.new(command_from_procfile, options) do |spawn|
     end
   end
+
+  def test_app_development_boot
+    options = {
+      timeout: 5,
+      wait_for: /Worker.+booted/,
+    }
+
+    ClimateControl.modify(RACK_ENV: "development", PORT: "5000") do
+      command = command_from_procfile(worker: "development")
+
+      WaitForIt.new(command, options) do |spawn|
+      end
+    end
+  end
 end