Return custom type

[sleek lantern]

Yes, as long as the other object is in the same module. From that error ("expected iterable") I assume what you have is different from what you shared here. Can you share the signature of the function you're calling, and the command you're using?

[red oracle]

@object_type
class ServiceContainer:
    name: str = field()
    port: int = field()
    ctr: dagger.Service


@object_type
class Localservice:
    services: list[ServiceContainer] = field(
        default=lambda: ServiceContainer(
            name="localstack",
            port=4566,
            ctr=dag.container()
            .from_("localstack/localstack:latest")
            .with_exposed_port(4566)
            .as_service(),
        )
    )

    @function
    async def add_service(self, name: str, path: Directory) -> "Localservice":
        port = random.choice(PORTS)
        ctr = dag.container().build(path).with_exposed_port(port).as_service()

        self.services.append(ServiceContainer(name=name, port=port, ctr=ctr))

        PORTS.remove(port)
        return self

    @function
    async def list_services(self) -> str:
        return ", ".join(
            [f"{service.name} ({service.port})" for service in self.services]
        )

Context: local testing of multiple containers + localstack

Have somewhat reworked this to avoid it:

@object_type
class Localservice:
    proxy = dag.proxy()

    @function
    async def add_service(self, name: str, path: Directory) -> "Localservice":
        port = random.choice(PORTS)
        ctr = dag.container().build(path).with_exposed_port(port).as_service()

        self.proxy.with_service(ctr, name, port, 80)

        PORTS.remove(port)
        return self

    @function
    async def run(self) -> dagger.Service:
        return self.proxy.service()

But out of interest I'd like to see the solution if it's possible

[sleek lantern]

Your default value for services is returning a single ServiceContainer but it's defined as list[ServiceContainer].

[red oracle]

That did it. Always something small. Thanks!

[sleek lantern]

Unrelated but you seem to be mutating a global PORTS. I'm afraid you may get unexpected behavior because each function runs in their own runtime container. They don't share the same process/memory. In order to preserve that state it would have to be a field in an object.

[red oracle]

I'm going to rework that and ask the user for a port anyway 🙂

[sleek lantern]

You can also let the engine assign a random one. Better chance to avoid a conflict. If random is what you actually want.

[red oracle]

Remind me how to do that? Don't think I recall ever doing so before