Lua HAProxy example

auth-request.lua

local http = require("http")

core.register_action("auth-request", { "tcp-req", "http-req" }, function(txn)
	auth_request(txn)
end, 0)

function set_var_pre_2_2(txn, var, value)
	return txn:set_var(var, value)
end
function set_var_post_2_2(txn, var, value)
	return txn:set_var(var, value, true)
end

set_var = function(txn, var, value)
	local success = pcall(set_var_post_2_2, txn, var, value)
	if success then
		set_var = set_var_post_2_2
	else
		set_var = set_var_pre_2_2
	end

	return set_var(txn, var, value)
end

function auth_request(txn)
	set_var(txn, "txn.auth_response_successful", false)
	txn:Info("auth_request: start")
	
	local auth_backend_name = "ll_auth_server"
	
	-- Check whether the given backend exists.
	if core.backends[auth_backend_name] == nil then
		txn:Alert("Unknown auth-request backend '" .. auth_backend_name .. "'")
		set_var(txn, "txn.auth_response_code", 500)
		return
	end
	txn:Info("auth_request: auth backend postoji")
	
	-- Check whether the given backend has servers that
	-- are not `DOWN`.
	local auth_srv_address_port = nil
	for name, server in pairs(core.backends[auth_backend_name].servers) do
		local status = server:get_stats()['status']
		if status == "no check" or status:find("UP") == 1 then
			auth_srv_address_port = server:get_addr()
			break
		end
	end
	if auth_srv_address_port == nil then
		txn:Warning("No servers available for auth-request backend: '" .. auth_backend_name .. "'")
		set_var(txn, "txn.auth_response_code", 500)
		return
	end
	txn:Info("auth_request: auth backend adresa: " .. auth_srv_address_port)
	
	local client_ip = txn.f:src()
	txn:Info("auth_request: client ip: " .. client_ip)
	
	local headers = {}
	local method = "GET"
	local response, err = http.send(method:upper(), {
		url = "http://" .. auth_srv_address_port .. "/haproxy?ip_address=" .. client_ip,
		headers = headers,
	})
	--TODO provjeriti err
	txn:Info("auth_request: status code: " .. response.status_code)
	txn:Info("auth_request: content: " .. response.content)
	
	if response.content == 'true' then
		set_var(txn, "txn.auth_response_successful", true)
	else
		set_var(txn, "txn.auth_response_successful", false)
	end
	
	
	txn:Info("auth_request: END")
	
end