Vue.js app works in development but not mounting template in production with Rails 5.2.0 / Webpacker - blank screen with no errors in console

Question

I\'m using Rails 5.2.0 and Webpacker gem to deploy a Vue application.

The show.html.erb file is very simple:

Answer 1

I had similar problem in Rails 5.2 + webpack Vue. All was good in development, but not working in production. After hours of investigating I found the reason. It was in this recommendation from webpaker gem docs.

Adding this

Rails.application.config.content_security_policy do |policy|
  if Rails.env.development?
    policy.script_src :self, :https, :unsafe_eval
  else
    policy.script_src :self, :https
  end
end

brokes production. Removing else part - fixing the situation.

Chrome silently ignoring this. Firefox shows warnings.