replace --agent-type with subcommand, #1032, #1085

[kba]

• Instead of an option --agent-type, implement the behavior as subcommands, i.e.

ocrd-foo --agent-type worker ...

becomes

ocrd-foo worker ...

Also removes the exception handling because it does not actually handle the exceptions, just stringifies them and we want full stack traces if something goes wrong.

[MehmedGIT]

Initially, I did not see a reason why we would need that change. However, now when I think about it, this refines the way we handle the worker and server subcommands. The --queue option is exclusive for the worker and the --address option is exclusive for the server.

So ocrd-* worker --help and ocrd-* server --help could have a more meaningful output for the general user.

Currently, ocrd-* --help is still lacking the --address flag and the additional processing worker flags (--create-queue and --queue-connect-attempts) added in #1075.

Options for Processing Worker server:
  --queue                         The RabbitMQ server address in format
                                  "amqp://{user}:{pass}@{host}:{port}/{vhost}"
                                  [amqp://admin:admin@localhost:5672]
  --database                      The MongoDB server address in format
                                  "mongodb://{host}:{port}"
                                  [mongodb://localhost:27018]
  --type                          type of processing: either "worker" or "server"

[MehmedGIT]

I could already push here the adaptation changes needed in the ocrd network to use the subcommands.

[MehmedGIT]

The bash library should still be adapted appropriately. Currently, it still accepts --type.

[kba]

So ocrd-* worker --help and ocrd-* server --help could have a more meaningful output for the general user.

OK, so how about three --help variants. One for the general CLI which lists the worker/server subcommands but omits the sections Options for Processing Worker: and Options for Processor Server:. Then one for ocrd-* worker --help which lists only those options and one for ocrd-* server which lists those options plus the general Options for processing?

[MehmedGIT]

That would be even better!

[kba]

The bash library should still be adapted appropriately. Currently, it still accepts --type.

Implemented in e6a35a1, now to fix the errors I've introduced apparently :/

[kba]

now to fix the errors I've introduced apparently :/

Debug echo&exit was still in there 🙃 time for weekend.