feat: allow sending headers upstream returned by OPA server

[Revolyssup]

Description

Fixes #9704

Documentation to be updated

Checklist

• I have explained the need for this PR and the problem it solves
• I have explained the changes or the new features added to this PR
• I have added tests corresponding to this change
• I have updated the documentation to reflect this change
• I have verified that this change is backward compatible (If not, please discuss on the APISIX mailing list first)

[monkeyDluffy6017]

Please make the ci pass and no test cases?

[Revolyssup]

Please make the ci pass and no test cases?

Added test case @monkeyDluffy6017

[Revolyssup]

@monkeyDluffy6017 PTAL

[monkeyDluffy6017]

Is it necessary to proxy all of opa's request headers?

[Revolyssup]

What else do you propose? How to select which ones to proxy?

[Sn0rt]

what HTTP header should pass upstream? instead of forwarding all HTTP header

[Sn0rt]

@chusov pls help us take a look

[chusov]

Maybe add a parameter with a list of headers?
send_header_upstream_list

[Revolyssup]

Maybe add a parameter with a list of headers? send_header_upstream_list

@monkeyDluffy6017 What do you think about this?

[monkeyDluffy6017]

@chusov i think the headers that need to be passed to upstream from OPA server should be fixed, what headers do you exactly need?

[chusov]

@monkeyDluffy6017
at the moment it is enough X-Username, in the future there were plans to add more depending on the service

[monkeyDluffy6017]

Maybe add a parameter with a list of headers? send_header_upstream_list

@monkeyDluffy6017 What do you think about this?

LGTM

[Revolyssup]

Maybe add a parameter with a list of headers? send_header_upstream_list

@monkeyDluffy6017 What do you think about this?

LGTM

Okay I'm making the change. @Sn0rt This one change remaining as suggested above by user

[monkeyDluffy6017]

Suggested change

	send_headers_upstream = {
	type = "array",
	minItems = 0,
	items = {
	type = "string"
	},
	description = "list of headers to pass to upstream in request"
	},
	send_headers_upstream = {
	type = "array",
	minItems = 1,
	items = {
	type = "string"
	},
	description = "list of headers to pass to upstream in request"
	},

[Revolyssup]

done

[monkeyDluffy6017]

Suggested change

	else if result.headers and #conf.send_headers_upstream > 0 then
	local headersToSend = {}
	for key in pairs(conf.send_headers_upstream) do
	headersToSend[key] = true
	end
	for key,value in pairs(result.headers) do
	if headersToSend[key] then
	core.request.set_header(ctx,key,value)
	end
	end
	end
	else if result.headers and conf.send_headers_upstream then
	local headersToSend = {}
	for key in pairs(conf.send_headers_upstream) do
	headersToSend[key] = true
	end
	for key,value in pairs(result.headers) do
	if headersToSend[key] then
	core.request.set_header(ctx,key,value)
	end
	end
	end

[monkeyDluffy6017]

The indent is not right, only four spaces are needed

[Revolyssup]

done

[monkeyDluffy6017]

Suggested change

	for key,value in pairs(result.headers) do
	for key, value in pairs(result.headers) do

[monkeyDluffy6017]

No blank is needed

[monkeyDluffy6017]

Suggested change

	core.request.set_header(ctx,key,value)
	core.request.set_header(ctx, key, value)

[monkeyDluffy6017]

I think you could refactor this block like this:

        for _, name in ipairs(conf.send_headers_upstream) do
            if result.headers[name] then
                core.request.set_header(ctx, name, value)
            end
        end

[Revolyssup]

Makes more sense. Done