CLI tool & correctly stopping it?

[ringods]

I am designing a data migration tool. To perform migration and intermediate transformation steps, each could be very elegantly be implmented as an actor. But when all the data is migrated, how should/would I signal this to all the actors to stop and be able to return an exit code from my main function?

[halturin]

I would use Events for that https://docs.ergo.services/basics/events

PS I'm working on act.Saga now, which is intended specifically for such cases. It will be a part of 3.1 release.

[ringods]

What is the 3.1 timeframe?

[halturin]

~ April 2025

[ringods]

@halturin I will have a look at Events. But when I look at the examples, they all seem to end with a node.Wait(), for instance:

https://github.com/ergo-services/examples/blob/0cc99885eef07c013ab86d968e7bd123f608c745/call/demo.go#L54

How should I implement a grafeful exit, preferrably with the ability to return an exit code as most CLI's have.

[halturin]

Use Stop method of gen.Node interface https://docs.ergo.services/basics/node#node-shutdown

There is no way to specify exit code so far. Probably good to add it at some point.

[ringods]

@halturin In one actor, I emit an event, with the last event having another message type. When that specific message is received on the subscriber side, I trigger:

	case backend.NoMoreStacksMessage:
		// All stack were emitted, so we stop the CLI
		a.Node().Stop()

and I get the following log messages:

1734687840811712000 [info] <420FB26D.0.1004>: Supervisor: terminate children <420FB26D.0.1005>
1734687840811738000 [info] <420FB26D.0.1004>: Supervisor: terminate children <420FB26D.0.1007>
1734687840811751000 [info] <420FB26D.0.1005>: terminated with reason: <420FB26D.0.1004>: shutdown

But my process does not end and return to the shell prompt. Both my Application and Supervisor are configured for transient restarts. What am I missing?

[halturin]

missing this one:

[ringods]

@halturin thanks for highlighting this. Calling it from a goroutine indeed solved it. Tnx.