Apply 7.0 default config and add cookie rotator

config/application.rb

@@ -21,8 +21,7 @@
 module CoredumpWaterSensorApi
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
-    config.load_defaults 6.1
-    config.active_support.cache_format_version = 7.0 # Can be removed when changing load_defaults to 7.0
+    config.load_defaults 7.0
 
     # Configuration for the application, engines, and railties goes here.
     #

config/initializers/cookie_rotator.rb

@@ -0,0 +1,19 @@
+Rails.application.config.after_initialize do
+  Rails.application.config.action_dispatch.cookies_rotations.tap do |cookies|
+    authenticated_encrypted_cookie_salt = Rails.application.config.action_dispatch.authenticated_encrypted_cookie_salt
+    signed_cookie_salt = Rails.application.config.action_dispatch.signed_cookie_salt
+
+    secret_key_base = Rails.application.secret_key_base
+
+    key_generator = ActiveSupport::KeyGenerator.new(
+      secret_key_base, iterations: 1000, hash_digest_class: OpenSSL::Digest::SHA1
+    )
+    key_len = ActiveSupport::MessageEncryptor.key_len
+
+    old_encrypted_secret = key_generator.generate_key(authenticated_encrypted_cookie_salt, key_len)
+    old_signed_secret = key_generator.generate_key(signed_cookie_salt)
+
+    cookies.rotate :encrypted, old_encrypted_secret
+    cookies.rotate :signed, old_signed_secret
+  end
+end