Implement a more generic parser for command line arguments

[andreeaflorescu]

We currently duplicate the parsing logic in the try_from functions of MemoryConfig, VcpuConfig, KernelConfig, NetConfig, BlockConfig. As we add more devices and configuration, this duplication generates too much boilerplate code.

We should try to see if we can somehow reduce this duplication (without adding new rust crates dependencies).

[FedericoPonzi]

Could you please assign this to me?

[andreeaflorescu]

@FedericoPonzi done! Happy coding!

[gabhijit]

Related: I am thinking whether it's a good idea to use builder pattern here. Something along the lines of hyper Request builder?

So the code would look like -

let vmm_cfg = VMMConfig::builder()
.memory(...)
.kernel(...)
.net(...)

And with right set of defaults, so not everything becomes a required config?

[andreeaflorescu]

Related: I am thinking whether it's a good idea to use builder pattern here. Something along the lines of hyper Request builder?

So the code would look like -

let vmm_cfg = VMMConfig::builder()
.memory(...)
.kernel(...)
.net(...)

I personally like the builder pattern, I wonder how much it helps in this scenario. A prototype would be nice.

And with right set of defaults, so not everything becomes a required config?

Besides the kernel path, for everything else we can have defaults.

@gabhijit are you interested in contributing your proposal?

[gabhijit]

@andreeaflorescu , Sure I can give it a try . Let me create a separate issue?

[andreeaflorescu]

@andreeaflorescu , Sure I can give it a try . Let me create a separate issue?

Yap, sounds good.