Update to Rails 6.0.0

config/initializers/content_security_policy.rb

@@ -21,6 +21,9 @@ end
 # If you are using UJS then enable automatic nonce generation
 # Rails.application.config.content_security_policy_nonce_generator = -> request { SecureRandom.base64(16) }
 
+# Set the nonce only to specific directives
+# Rails.application.config.content_security_policy_nonce_directives = %w(script-src)
+
 # Report CSP violations to a specified URI
 # For further information see the following documentation:
 # https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Content-Security-Policy-Report-Only