Going from describe_task_definition to register_task_definition

[canadiannomad]

I feel like I'm using the SDK in hard mode.. So it is likely just a misunderstanding of mine... Yet I can't find decent documentation on how to do it...
How can I take the output from a "describe" function, modify it, and send it to an update function without going through .every .single.function. of the associated builder?

Currently I have code similar to the following:

        let task_definition_output = ecs_client
            .describe_task_definition()
            .task_definition(task_definition_name)
            .send()
            .await?;
            
       let mut task_definition = task_definition_output.task_definition.unwrap();
       // ... make modifications to task_definition ... 
       
       let register_task_definition_output = ecs_client
            .register_task_definition()
            .set_family(task_definition.family)
            .set_task_role_arn(task_definition.task_role_arn)
            .set_execution_role_arn(task_definition.execution_role_arn)
            .set_network_mode(task_definition.network_mode)
            .set_container_definitions(task_definition.container_definitions)
            .set_volumes(task_definition.volumes)
            .set_placement_constraints(task_definition.placement_constraints)
            .set_requires_compatibilities(task_definition.requires_compatibilities)
            .set_cpu(task_definition.cpu)
            .set_memory(task_definition.memory)
            .set_inference_accelerators(task_definition.inference_accelerators)
            .set_pid_mode(task_definition.pid_mode)
            .set_ipc_mode(task_definition.ipc_mode)
            .set_proxy_configuration(task_definition.proxy_configuration)
            .send()
            .await?;

When I really feel like I should be able to do something like:

        let task_definition_output = ecs_client
            .describe_task_definition()
            .task_definition(task_definition_name)
            .send()
            .await?;
            
       let mut task_definition = task_definition_output.task_definition.unwrap();
       // ... make modifications to task_definition ... 
       
       let register_task_definition_output = ecs_client
            .register_task_definition()
            .from_task_definition(task_definition.clone())
            .send()
            .await?;

Or more generically I'd love to be able to skip the builder altogether, and send a *Input to the client.. eg:

let register_task_definition_input = RegisterTaskDefinitionInput {
 ...
}
ecs_client.from_input(register_task_definition_input).send();

Then I'd be able to create my own helpers to convert one to the other. (In many cases it is a 1:1 value copy..)

So what is it that I'm missing to be able to do these describe-modify-update type actions using the SDK?

[jdisanti]

You're not missing anything. The way ECS is modeled is just not well tailored to this use-case.

[canadiannomad]

Fair enough, unfortunately it isn't just ECS though..

Describe ELB, Update ELB
Describe ALB Rule, Update ALB Rule
Describe Lambda Function, Update Lambda Function
Describe EC2, Create EC2

The SDK seems to break this generic case of "describe something, create/update similar something".