ngx.req.get_header()获取请求的请求头，

ngx.req.get_header()获取请求的请求头，

获取请求头str字符串

local = header_str = ngx.say(ngx.req.raw_header())
print(header_str)

获取请求头table

local headers = ngx.req_get_headers()
for k, v in pairs(headers) do
     print(k .. ":" .. v)
end

local headers = ngx.req.get_headers()

if not headers["parent"] then
    config_file = ngx.var.config_file
    for line in io.lines(config_file) do
        id = string.match(line, "id:%s?(%w+)")
        if id then
            return id
        end
    end
    return ""
else
    return headers["parent"]
end