List of workers can give wrong result

[jirihnidek]

Describe the bug
List of workers can be incomplete or it can contain workers that are not active anymore

To Reproduce

1. Start yggdrasil on Terminal 1: go run ./cmd/yggd --server tcp://localhost:1883 --log-level trace --client-id $(hostname)
2. Start echo worker on Terminal 2: go run ./worker/echo -log-level trace
3. Try to get list of workers on Terminal 3 using: go run ./cmd/yggctl workers list or busctl --user call com.redhat.Yggdrasil1 /com/redhat/Yggdrasil1 com.redhat.Yggdrasil1 ListWorkers

Current result
List of workers is empty. The worker gets into the list of workers only after receiving the first message from MQTT.

Expected behavior
List of running workers.

Something like this in the case of yggctl:

echo - DispatchedAt:
echo - Version: 1

Something like this in the case of busctl (or any other D-Bus app):

a{sa{ss}} 1 "echo" 2 "Version" "1" "DispatchedAt" ""

Additional Information

• OS: Fedora 38
• Version: main branch

When worker has been stopped, then you can still see worker in the list of active workers despite MQTT message for the worker has been received and yggdrasil wasn't able to dispatch data from the MQTT message.

[jirihnidek]

Started discussion that is related to this issue: #169

[subpop]

Each worker is expected to own a name on the bus under the namespace com.redhat.Yggdrasil1.Worker1 (i.e. com.redhat.Yggdrasil1.Worker1.echo). When asked for a list of workers, yggd should enumerate all names on the bus, filter for names that begin with the namespace value above, and return the results.