Add cookie sharing with subdomains

src/invidious.cr

@@ -846,8 +846,13 @@ post "/login" do |env|
           secure = false
         end
 
+        if CONFIG.domain
+          env.response.cookies["SID"] = HTTP::Cookie.new(name: "SID", domain: ".#{CONFIG.domain}", value: sid, expires: Time.now + 2.years,
+            secure: secure, http_only: true)
+        else
           env.response.cookies["SID"] = HTTP::Cookie.new(name: "SID", value: sid, expires: Time.now + 2.years,
             secure: secure, http_only: true)
+        end
       else
         error_message = "Invalid username or password"
         next templated "error"
@@ -891,9 +896,14 @@ post "/login" do |env|
         secure = false
       end
 
+      if CONFIG.domain
+        env.response.cookies["SID"] = HTTP::Cookie.new(name: "SID", domain: ".#{CONFIG.domain}", value: sid, expires: Time.now + 2.years,
+          secure: secure, http_only: true)
+      else
         env.response.cookies["SID"] = HTTP::Cookie.new(name: "SID", value: sid, expires: Time.now + 2.years,
           secure: secure, http_only: true)
       end
+    end
 
     env.redirect referer
   end

src/invidious/helpers/helpers.cr

@@ -16,6 +16,7 @@ class Config
     hmac_key:     String?,
     full_refresh: Bool,
     geo_bypass:   Bool,
+    domain:       String?,
   })
 end