Simplify GitSource proxy settings

[imjasonh]

The GitSource type has a few fields related to proxying requests:

type GitSource struct {
...
	HTTPProxy string  `json:"httpProxy,omitempty"`
	HTTPSProxy string `json:"httpsProxy,omitempty"`
	// NoProxy can be used to specify domains for which no proxying should be performed. Optional.
	NoProxy string.   `json:"noProxy,omitempty"`
...
}

(ref)

Would it make sense to communicate this information in one field, Proxy string json:"proxy"`?

At the time people are defining the source, they would know whether it's an HTTP or HTTPS repo, and I don't know why they'd want to specify "don't proxy this domain" -- is that the default?

These were added long long ago, alongside a lot of other stuff, so I don't know if they were added with a particular purpose in mind. @sbose78 might know.

With a single Proxy field, we could generate HTTPS_PROXY=${proxy} HTTP_PROXY=${proxy} git clone ${url} if it's set, and just git clone ${url} otherwise, unless there's some semantics to Git proxying I'm not understanding (entirely possible!)

(This isn't a high priority but it might make sense to try to do this before v1beta1 and definitely before v1)

[imjasonh]

/kind cleanup
/priority awaiting-more-evidence

[imjasonh]

/kind api-change

[imjasonh]

Upon further review, these fields don't seem to be hooked up to anything, and should be safe to remove. If anybody was setting them before, they weren't doing anything. I'll send a PR to remove them.

/assign

[sbose78]

Yeah they were added long ago with a hope that they would be utilised soon enough. It's been close to a year, we may remove these. And bring them in with an enhancement proposal if needed.

[sbose78]

I'm good with using a single field later on. 👍