Display notification that max concurrent sessions has been reached (GRN-41) (#317)

* <Added max concurrent sessions check>

* <Refactored some exception logic>

* <Fixed code style>

* <Generalized BBBException error message>

app/controllers/rooms_controller.rb

@@ -94,7 +94,11 @@ class RoomsController < ApplicationController
     opts = default_meeting_options
     opts[:user_is_moderator] = true
 
-    redirect_to @room.join_path(current_user.name, opts, current_user.uid)
+    begin
+      redirect_to @room.join_path(current_user.name, opts, current_user.uid)
+    rescue BigBlueButton::BigBlueButtonException => exc
+      redirect_to room_path, notice: I18n.t(exc.key.to_s.underscore, default: I18n.t("bigbluebutton_exception"))
+    end
 
     # Notify users that the room has started.
     # Delay 5 seconds to allow for server start, although the request will retry until it succeeds.

app/models/room.rb

@@ -63,6 +63,7 @@ class Room < ApplicationRecord
       bbb.create_meeting(name, bbb_id, create_options)
     rescue BigBlueButton::BigBlueButtonException => exc
       puts "BigBlueButton failed on create: #{exc.key}: #{exc.message}"
+      raise exc
     end
   end
 

app/views/rooms/show.html.erb

@@ -13,6 +13,14 @@
 # with BigBlueButton; if not, see <http://www.gnu.org/licenses/>.
 %>
 
+<% unless flash.empty? %>
+  <%= render "shared/error_banner" do %>
+    <% flash.each do |key, value| %>
+      <%= content_tag :div, value, class: "flash #{key} d-inline" %>
+    <% end %>
+  <% end %>
+<% end %>
+
 <div class="background pb-1">
   <div class="container">
     <div class="row pt-9">

config/locales/en.yml

@@ -22,6 +22,7 @@ en:
       user:
         accepted_terms: "Terms and Conditions"
   bigbluebutton: BigBlueButton
+  bigbluebutton_exception: Oops, there was an error when starting the meeting!
   cancel: Cancel
   copy: Copy
   delete: Delete
@@ -78,6 +79,7 @@ en:
     version: We've released a new version of Greenlight, but your database isn't compatible.
   ldap_error: Unable to connect to the LDAP server. Please check your LDAP configuration in the env file and ensure your server is running.
   login: Sign in
+  max_concurrent: The maximum number of concurrent sessions allowed has been reached!
   modal:
     create_room:
       auto_join: Automatically join me into the room.