Ansible Yum Upgrade Failure

ERROR! 'sudo' is not a valid attribute for a Play

The error appears to be in '/home/jp025343/ansible/playbooks/yum-upgrade.yml': line 2, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

# Playbook for upgrading all Graylog nodes
- hosts: graylog
  ^ here