To share the sessions across subdomains for a Rails a app, you may set the configuration like this as the documentation suggest:

App.config.session_store ... , :domain => :all

Unfortually, it does’t work unless you’re visit by localhost.

The :all defaults to a TLD length of 1, which means if you’re testing with Pow (myapp.dev) it does’t work because the TLD is 2:

App.config.session_store ... , :domain => :all, :tld_length => 2


[References]

  • http://excid3.com/blog/sharing-a-devise-user-session-across-subdomains-with-rails-3/
  • http://stackoverflow.com/questions/10402777/share-session-cookies-between-subdomains-in-rails/15009883#15009883