Recently I had a strange problem when sessions didn’t work on my site on Rails in production environment. The problem was in Internet Explorer while it worked in Firefox and Chrome.
I found out that Internet Explorer doesn’t set cookies for some reason.
I’ve tried many settings for session_store in my config like
config.session_store :cookie_store, key: '_sess', :domain => :all
config.session_store :cookie_store, key: '_sess', :domain => '.mysite.com'
config.session_store :cookie_store, key: '_sess', :domain => '.mysite.com', :secure => falseand many many others. But it didn’t help.
The problem was in the name of my subdomain – it had an underscore ( “_” ), for example, dev_rails.mysite.com.
IE has problems accepting cookies from subdomains that contain underscore.
In order to work in IE subdomains must meet the requirements of the URI RFC.
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