Migrate from Google Analytics and Mixpanel to Ahoy

[ferblape]

We are removing application Google Analytics service and replacing it by Ahoy. If a customer setup its own analytics code, it'll be kept, meaning customers that don't set an Analytics code will have Ahoy stats.

Right now there are two analytics signatures installed:

• by default, the application installs the code defined in config/application.ymlsetting
• optional, the site has an attribute to set a specific code. We are keeping this code if has been set

First part: remove Analytics

• remove the attribute from config/application.yml and update docs
• remove the app analytics JS from the templates. If the customer is using it's own code, keep it
• extra ball: remove references to Mixpanel

Second part: add Ahoy track

• install ahoy gem
• track site visits, probably in an after filter
• track visits with a sidekiq job
• configure it to track site requests. Keep in mind the multitenancy, so you might wan to add the site host to the ahoy event

[furilo]

Some clients are using their own Analytics. Maybe if a custom Analytics ID has been set up from the admin, we should leave it?

[ferblape]

You are right, I'll reword the issue

[furilo]

We should activate this: https://github.com/ankane/ahoy#gdpr-compliance-1