Code review comment for lp://staging/~cjohnston/ubuntu-ci-services-itself/ts-ticket-read-api

> Francis, how will the ticket statuses be kept up to date?

The original design had the ticket system polling the lander for progress. This was updated to use a message queue instead. The ticket system provides a message queue handle to the lander as part of the execute_request call. The lander then uses this to provide regular progress updates (every 60 seconds or sooner if status changes). The exact details of what is in the message haven't been designed yet, but it would probably have to provide the status of all lander stages in each message. For example:

{"Package Building": "Completed",
 "Image Building": "In Progress",
 "Image Testing": "Not Started",
 "Package Publishing": "Not Started"}