Add specific DecodeURL function in decoder package

[dmvolod]

What do you want to see?

As developer, I would like to have out-of the-box solution to stream documents from the URL and decode them.
Yes, most of the functions utilize io.Reader and can be wrapped, but separate specific function is much better to use.
This will help in situations where we need to install components from URL, such as Prometheus or CertManager in examples.

Extra Labels

No response

[dmvolod]

/assign

[vladimirvivien]

Hi @dmvolod can you provide a concrete code example to help with this issue?

[dmvolod]

Hi @vladimirvivien

I would like to utilize this function in controller tests and examples as well to replace kubectl binary involving for installing/removing CertManager and Prometheus.
It would be nice to avoid using third-party tools in e2e test when possible to reduce CI images size and reduce number of problems when binaries are not found there or locally.

The code will look like this

	r, err := resources.New(cfg.Client().RESTConfig())
	if err != nil {
		return ctx, err
	}
	err = decoder.DecodeURL(
		ctx,
		certMgrUrl,
		decoder.CreateHandler(r),
	)
	if err != nil {
		return ctx, err
       }

Thank you.