---
upgrade:
  - |
    Composable service templates can now define external_update_tasks
    and external_upgrade_tasks. They are meant for update/upgrade
    logic of services deployed via external_deploy_tasks. The external
    update playbook first executes external_update_tasks and then
    external_deploy_tasks, the procedure for upgrades works
    analogously. All happens within a single playbook, so variables or
    fact overrides exported from the update/upgrade tasks will be
    available to the deploy tasks during the update/upgrade procedure.