concourse-worker-ecs-registration-issue

gistfile1.txt

the worker's logs contain the guardian boot logs ending with:
{"timestamp":"2019-03-13T16:47:15.393870712Z","level":"info","source":"guardian","message":"guardian.start.completed","data":{"session":"6"}}
{"timestamp":"2019-03-13T16:47:15.393904447Z","level":"info","source":"guardian","message":"guardian.list-containers.starting","data":{"session":"31"}}
{"timestamp":"2019-03-13T16:47:15.393977952Z","level":"info","source":"guardian","message":"guardian.list-containers.finished","data":{"session":"31"}}
{"timestamp":"2019-03-13T16:47:15.394037655Z","level":"info","source":"guardian","message":"guardian.started","data":{"addr":"0.0.0.0:7777","network":"tcp"}}

followed by this block of worker logs which repeats endlessly (and no logs regarding tsa registration):
{"timestamp":"2019-03-13T16:55:18.819487298Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:23.819466498Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:28.819417692Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:33.819386132Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:38.819407749Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:43.807490461Z","level":"info","source":"guardian","message":"guardian.list-containers.starting","data":{"session":"48"}}
{"timestamp":"2019-03-13T16:55:43.807570726Z","level":"info","source":"guardian","message":"guardian.list-containers.finished","data":{"session":"48"}}
{"timestamp":"2019-03-13T16:55:43.819367997Z","level":"debug","source":"worker","message":"worker.beacon-runner.beacon.keepalive.tick","data":{"session":"9.1.2"}}
{"timestamp":"2019-03-13T16:55:43.827133863Z","level":"debug","source":"worker","message":"worker.sweeper-runner.tick.run.command-exited","data":{"command":"report-containers","session":"12.17.2"}}
{"timestamp":"2019-03-13T16:55:43.847025669Z","level":"debug","source":"worker","message":"worker.sweeper-runner.tick.run.command-exited","data":{"command":"report-volumes","session":"12.17.5"}}
{"timestamp":"2019-03-13T16:55:43.862499890Z","level":"debug","source":"worker","message":"worker.sweeper-runner.tick.run.command-exited","data":{"command":"sweep-containers","session":"12.17.7"}}
{"timestamp":"2019-03-13T16:55:43.877986725Z","level":"debug","source":"worker","message":"worker.sweeper-runner.tick.run.command-exited","data":{"command":"sweep-volumes","session":"12.17.9"}}

Are you previously / currently using direct worker registration? from the release notes under one of the many breaking changes:

Along the way, we removed support for direct worker registration.
The --peer-ip flag is no longer available on concourse worker. 
To transition to 5.0, just remove the flag - the worker will register via forwarding instead.

...also that was a blind guess so sorry if this doesnt help you at all