Add flag to use webhooks and API call to register a hook

It almost works with webhooks now. Still TODO is:
* Remove the hook after the recording is published
* To process the publish_ended event from the webhooks either the webhook
  needs to include the metadata (currently it doesn't) or GreenLight has
  find out the meeting token without reading it from the metadata.

app/controllers/bbb_controller.rb

@@ -155,18 +155,31 @@ class BbbController < ApplicationController
   end
 
   def treat_callback_event(event)
+    eventName = (event.present? && event['header'].present?) ? event['header']['name'] : nil
 
     # a recording is ready
-    if event['header']['name'] == "publish_ended"
-      token = event['payload']['metadata'][META_TOKEN]
-      record_id = event['payload']['meeting_id']
+    if eventName == "publish_ended"
+      if event['payload'] && event['payload']['metadata'] && event['payload']['meeting_id']
+        token = event['payload']['metadata'][META_TOKEN]
+        record_id = event['payload']['meeting_id']
 
-      # the webhook event doesn't have all the data we need, so we need
-      # to send a getRecordings anyway
-      # TODO: if the webhooks included all data we wouldn't need this
-      rec_info = bbb_get_recordings(token, record_id)
-      rec_info = rec_info[:recordings].first
-      RecordingCreatedJob.perform_later(token, parse_recording_for_view(rec_info))
+        # the webhook event doesn't have all the data we need, so we need
+        # to send a getRecordings anyway
+        # TODO: if the webhooks included all data in the event we wouldn't need this
+        rec_info = bbb_get_recordings(token, record_id)
+        rec_info = rec_info[:recordings].first
+        RecordingCreatedJob.perform_later(token, parse_recording_for_view(rec_info))
+
+        # TODO: remove the webhook now that the meeting and recording are done
+        # remove only if the meeting is not running, otherwise the hook is needed
+        # if ENV['GREENLIGHT_USE_WEBHOOKS']
+        #   webhook_remove("#{base_url}/callback")
+        # end
+      else
+        logger.error "Bad format for event #{event}, won't process"
+      end
+    else
+      logger.info "Callback event will not be treated. Event name: #{eventName}"
     end
 
     render head(:ok) && return

app/lib/bbb_api.rb

@@ -78,9 +78,13 @@ module BbbApi
           "meta_#{BbbApi::META_TOKEN}": meeting_token
         }
 
-        meeting_options.merge!(
-          { "meta_#{BbbApi::META_HOOK_URL}": options[:hook_url] }
-        ) if options[:hook_url]
+        if ENV['GREENLIGHT_USE_WEBHOOKS']
+          webhook_register(options[:hook_url], meeting_id)
+        else
+          meeting_options.merge!(
+            { "meta_#{BbbApi::META_HOOK_URL}": options[:hook_url] }
+          ) if options[:hook_url]
+        end
 
         # Create the meeting
         bbb.create_meeting(options[:meeting_name], meeting_id, meeting_options)
@@ -253,6 +257,26 @@ module BbbApi
     }
   end
 
+  def webhook_register(url, meeting_id=nil)
+    params = { callbackURL: url }
+    params.merge!({ meetingID: meeting_id }) if meeting_id.present?
+    bbb_safe_execute :send_api_request, "hooks/create", params
+  end
+
+  def webhook_remove(url)
+    res = bbb_safe_execute :send_api_request, "hooks/list"
+    if res && res[:hooks] && res[:hooks][:hook]
+      res[:hooks][:hook] = [res[:hooks][:hook]] unless res[:hooks][:hook].is_a?(Array)
+      hook = res[:hooks][:hook].select{ |h|
+        h[:callbackURL] == url
+      }.first
+      if hook.present?
+        params = { hookID: hook[:hookID] }
+        bbb_safe_execute :send_api_request, "hooks/destroy", params
+      end
+    end
+  end
+
   def success_join_res(join_url)
     {
       returncode: true,

sample.env

@@ -7,6 +7,16 @@ RAILS_ENV=development
 BIGBLUEBUTTON_ENDPOINT=http://test-install.blindsidenetworks.com/bigbluebutton/
 BIGBLUEBUTTON_SECRET=8cd8ef52e8e101574e400365b55e11a6
 
+# If "true", GreenLight will register a webhook callback for each meeting
+# created. This callback is called for all events that happen in the meeting,
+# including the processing of its recording. These events are used to update
+# the web page dynamically as things happen in the server.
+# If not "true", the application will add a metadata to the meetings with this same
+# callback URL. Scripts can then be added to BigBlueButton to call this callback
+# URL and send specific events to GreenLight (e.g. a post publish script to warn
+# the application when recordings are done).
+GREENLIGHT_USE_WEBHOOKS=false
+
 # OmniAuth
 TWITTER_ID=
 TWITTER_SECRET=