Envoy's L4 Golang extension

[antJack]

Recently, my team implemented the L7 golang extension. Similarly, we have implemented an L4 golang extension using the same cgo technique as L7. And the L4 extension has already been widely utilized within our company for almost a year, enabling our internal customized protocol to benefit from the high-performance network infrastructure of Envoy and the superior development efficiency of Golang. Additionally, the L4 golang extension can also provide a better implementation path for envoy's future support of Dapr, etc. Given the above, we are consider to open source our L4 golang extension very soon.

[taoyuanyuan]

Cool stuff !~

[rakesh-eltropy]

I tired to use this extension.

func (f *filter) DecodeHeaders(header api.RequestHeaderMap, endStream bool) api.StatusType {

	f.path, _ = header.Get(":path")
	fmt.Println(f.path)

	method, _ := header.Get(":method")
	fmt.Println(method)

	useragent, _ := header.Get(":useragent")
	fmt.Println(useragent)

	host, _ := header.Get(":host")
	fmt.Println(host)
	

	if f.path == "/localreply_by_config" {
		return f.sendLocalReplyInternal()
	}
	return api.Continue
}

I am able to get path and method but other headers are blank. Also, I see header.Range is still not implemented so not sure what all keys are available. Can you please guide me how to get host, useragent, cookies etc headers.

[doujiang24]

@rakesh-eltropy This issue is for L4 filter, while your question is L7 filter related, better create a new issue for it.

For your questions:

1. for the keys of the header, you could follow this, i.e. header.Get("user-agent").
   https://github.com/envoyproxy/envoy/blob/main/source/common/http/headers.h#L212
2. we plan to introduce some new methods in the HeaderMap interface, i.e. Host, Path, Method and etc. so that people could use it easier.

Yep, Range and doc are on the way, thanks for your try and reminder.

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[antJack]

#26173

[github-actions]

This issue has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in the next 7 days unless it is tagged "help wanted" or "no stalebot" or other activity occurs. Thank you for your contributions.

[huanghuangzym]

#26173

when will support l4 extenstion?