Disable push and tag push events for the primary Geo system hook

Closes #1752

app/models/geo_node.rb

@@ -141,6 +141,8 @@ class GeoNode < ActiveRecord::Base
     if self.primary?
       self.oauth_application = nil
       update_clone_url
+      self.system_hook.push_events = false
+      self.system_hook.tag_push_events = false
     else
       update_oauth_application!
       update_system_hook!

db/migrate/20170419063751_remove_push_events_from_geo_primary_system_hook.rb

+class RemovePushEventsFromGeoPrimarySystemHook < ActiveRecord::Migration
+  include Gitlab::Database::MigrationHelpers
+
+  DOWNTIME = false
+
+  # Older version of Geo added push and tag push events to the
+  # primary system hook. This would cause unnecessary hooks to be
+  # fired.
+  def up
+    return unless geo_enabled?
+
+    execute <<-SQL
+      UPDATE web_hooks
+      SET push_events = false, tag_push_events = false WHERE
+      type = 'SystemHook' AND
+      id = (
+      SELECT system_hook_id FROM geo_nodes WHERE
+        host = #{quote(Gitlab.config.gitlab.host)} AND
+        port = #{quote(Gitlab.config.gitlab.port)} AND
+        relative_url_root = #{quote(Gitlab.config.gitlab.relative_url_root)});
+    SQL
+  end
+
+  def geo_enabled?
+    select_all("SELECT 1 FROM geo_nodes").present?
+  end
+end

spec/models/geo_node_spec.rb

@@ -46,6 +46,20 @@ describe GeoNode, type: :model do
     end
   end
 
+  context 'system hooks' do
+    it 'primary creates a system hook with no push events' do
+      hook = primary_node.system_hook
+      expect(hook.push_events).to be_falsey
+      expect(hook.tag_push_events).to be_falsey
+    end
+
+    it 'secondary creates a system hook with push events' do
+      hook = new_node.system_hook
+      expect(hook.push_events).to be_truthy
+      expect(hook.tag_push_events).to be_truthy
+    end
+  end
+
   context 'prevent locking yourself out' do
     subject do
       GeoNode.new(host: Gitlab.config.gitlab.host,